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Back to Annual Meeting Program
TUESDAY AFTERNOON, April 28, 1992
1:45 p.m. SIMULTANEOUS SCIENTIFIC SESSION A - ADULT CARDIAC SURGERY - Los Angeles Ballroom
18. Prolonged Orthotopic Xenoheart Transplantation in Infant Baboons
KAWAUCHI MOTOHIRO, M.D.*, STEVEN R. GUNDRY, M.D., JAVIER ALONSO de BEGONA, M.D.*, FRANCOIS BOUCHART, M.D.*, ANEES J. RAZZOUK, M.D.*, NORI FUKUSHIMA, M.D.*, ARTHUR J. HAUCK, M.D.* DOUGLAS A. WEEKS, M.D.*, SANDRA NEHLSEN-CANNARELLA, Ph.D.* and LEONARD L. BAILEY, M.D. Lotna Linda, California
The donor pool for infant heart transplantation is severely limited. Many infants die each year awaiting suitable donor hearts. To study the feasibility of an animal donor "bridge" to allotransplantation, we examined Orthotopic concordant xenotransplantation in a juvenile primate model. Eighteen donor rhesus monkeys weighing 2.4-3.8 kg (mean 2.9 kg) were matched with juvenile baboons, aged 9-19 months (mean 12.7 mo) and weighing 3.2-4.8 kg (mean 3.9 kg) using ABH blood type and mixed lymphocyte culture. Rhesus monkey hearts were orthotopically transplanted without immunosuppression into six control baboons (Or. 1). In five baboons (Gr. 2), 4 mg/kg/day of an-tilymphocyte globulin (ALG) was given for 3 days preoperatively and 5 days postoperatively. Splenectomy was also performed, and 18 mg/kg/day of oral FK506 was administered. Intravenous Methotrexate and/or Methylpred-nisolone were used as rescue therapy. Seven baboons (Gr. 3), received the same immunosuppression as Gr. 2, but an intravenous dose of Methotrexate (0.1-5 mg) was given twice weekly to suppress the proliferative response monitored by in vitro immunologic assays. Baboons in Gr. 1 survived 6,7,8,8,9 and 10 days (mean 8 days); all died from rejection. Baboons in Gr. 2 survived 25,32,53,57 and 75 days (mean 48.4 days) (p<0.05 vs Gr. 1). Two died during rescue therapy for rejection and three died from CMV infection. Two baboons in Gr. 2 revealed mild rejection at autopsy. Three baboons in Gr. 3 succumbed at 35,43 and 96 days; one from pulmonary infection, one from CMV pneumonia, and one from renal failure aggravated by Gancyclovir. Only one of the 3 deceased baboons in Gr. 3 showed mild rejection at autopsy. Four baboons in Gr. 3 remain alive and well 43,105,113 and 127 days posttransplantation (mean 80 days). FK-506 coupled with low-dose maintenance Methotrexate has produced host survival in this xenotransplant model. Results suggest that concordant xenotransplantation would be a suitable biologic bridge to allotransplanta-tion in infant recipients.
*By Invitation 19. Defibrillator Therapy in Ischemic and Non-Ischemic Ventricular Arrhythmias
T. BRUCE FERGUSON, JR., M.D.*, BRUCE D. LINDSAY, M.D.*, MICHAEL E. CAIN, M.D.* and JAMES L. COX, M.D. St. Louis, Missouri
The role of the implantable cardioverter-defibrillator (ICD) is non-ischemic ventricular arrhythmias (tachycardia-VT, fibrillation-VF, and sudden cardiac death-SCD is well established. However, its role in ischemic VT that is refractory to conventional medical therapy is less clear; ablative surgical procedures and amiodarone provide alternative therapies to the ICD for VT. Over the past four years, we have followed the treatment algorithm that 1) ablative surgery for cure of VT is preferable in patients with discrete aneurysms and preserved regional ventricular function; 2) all other patients who are not candidates for direct surgery (e.g., severe global dysfunction) undergo ICD implantation, if VT criteria are met; and 3) due to the side effects of the drug, amiodarone is used only if an ICD is not indicated. Potentially, however, this approach might increase the mortality in the ICD group by selecting out the best VT patients for ablative surgery and by including patients in whom amiodarone should be the preferred treatment. Therefore, our experience with 93 consecutive patients undergoing complete ICD system placement for ischemic (ISCH) and non-ischemic (NI) VT/VF was examined. Data are expressed as mean ± SD; (significance: p<0.05, independent Student's t test):
*(LESD = least energy for 3 successful defibnllations)
Eight total (5 ISCH, 3 NI) patients were transplant candidates. 19 ISCH patients underwent concomitant coronary bypass grafting. All perioperative deaths in the ISCH group were due to myocardial infarction and ventricular failure; the NI death was due to amiodarone toxicity. In all patients with manifestations of amiodarone toxicity, surgical mortality for ICD implantation was 50%. Kaplan-Meier analysis (Mantel-Haenszel) demonstrated that freedom from SCD and any death was not different between the groups. Therefore, despite worse ventricular function, concomitant coronary disease and higher LESDs, the surgical mortality, long-term survival and freedom from SCD following ICD implantation in ISCH patients is not significantly different from that for ICD patients with NI disease; the somewhat higher mortality in the ISCH group is directly related to the underlying coronary disease and not the VT. ICD therapy in these ischemic patients who do not meet criteria for ablative and potentially curative surgery is comparable to ICD therapy in non-ischemic patients; this ICD patient stratification should become useful when less surgically invasive implant techniques are considered.
*By Invitation 20. Clinic, Hemodynamic and Electrophysioiogic Results of 200 Left Ventricular Patch Reconstructions for Post Infarction Left Ventricular Aneurysm
VINCENT DOR, M.D., MICHEL SABATIER, M.D.*, FRANCOISE MONTIGLIO, M.D.*, MOHAMED SAAB, M.D.* PHILIPPE COSTE, M.D.*, PHILIPPE ROSSI, M.D.* and MARISA DiDONATO, M.D* Monte Carlo, Monaco
From 1987 to 1991, 200 consecutive pts (181 men and 19 women, mean age 58 ±9 yr), with postinfarction left ventricular (LV) aneurysm (187 anterior and 13 posterior) underwent LV reconstruction (LVR). Surgical technique consisted of endoventricular circular patch plasty with septal exclusion, using a circular patch of synthetic or autologous tissue anchored inside the LV in the contractile myocardium, after the resection of the endocardial scar and resection or exclusion of the aneurysm. Methods: all pts underwent complete hemodynamic study (right and left heart catheterization, ventricular angiography and coronary arteriography) before and early after surgery (9-12 days). 115/200 pts underwent programmed right ventricular stimulation (PVS), before and after surgery. At present, clinical follow up is available in 148 of the surviving pts; 60 of them underwent complete hemodynamic study, including PVS, after 1 yr. Preoperative data: 33 pts were operated in emergency. 145 pts were in NYHA class III-IV (72%); 31/200 pts had spontaneous VT (15%) and 46/115 had inducible VT (40%). Mean EF was 36 ± 14% (EF <40% in 116 pts and <20% in 18 pts) Contractile EF was 44 ± 11%. Postoperative results: LVR was performed with a synthetic patch in 115 pts and with autologous patch in 85. Non guided subtotal endocardectomy was performed in all pts with spontaneous and inducible VT, 24 of them had associated cryotherapy. Complete myocardial revascularization was performed in 189 pts (95%). Global peroperative mortality was 6.5% (13 pts). Early control: Mean EF significantly increased (49 ± 13%, p<0.01); no pt had EF <20%; 29 pts had EF <40%. When LV function has been evaluated by pressure-volume and pressure length loops, preop abnormal morphology and orientation of the loops tend to normalize after surgery. 42 out of the 44 surviving pts with preop inducible VT had non inducible VT after surgery (95% p<0.01); 29 out of the 30 surviving pts with preop spontaneous VT had no spontaneous or provoked arrythmias after surgery. 8 pts without preop inducible VT had postop inducible VT and 1 pt without preop spontaneousVT had postop spontaneous VT. Late control: In the 60 pts controlled after 1 year, EF was still significantly increased (44 ± 13, p<.05). VT was induced in 3 pts and no spontaneous episodes of VT have been recorded. Late mortality (interval 3m-4yr) was 11/148 pts (7.4%); in 6 pts it was not of cardiac origin. 88% of pts were in NYHA class I-II. One pt underwent redux surgery for a false aneurysm after 1 year.
2:45 p.m. INTERMISSION - VISIT EXHIBITS
*By Invitation 3:15 p.m. SIMULTANEOUS SCIENTIFIC SESSION A - ADULT CARDIAC SURGERY - Los Angeles Ballroom
21. Aprotinin Partially Inhibits the Contact and Platelet Activation Systems During Extracorporeal Perfusion
YANINA T. WACHTFOGEL, M.D.*, UMBERTO KUCICH, Ph.D.*, C. KIRK HACK, M.D.*, STEFAN NIEWIAROWSKI, M.D.*, ROBERT W. COLMAN, M.D.* and L. HENRY EDMUNDS, JR., M.D. Philadelphia, Pennsylvania
Aprotinin reduces blood loss after cardiac surgery by inhibiting plasmin and decreasing bleeding times. The mechanism of action of aprotinin on the contact system of plasma proteins, which mediates part of the "whole body inflammatory response", and on platelets is not clearly understood. We investigated the effect of aprotinin at four different doses on the contact activation system, neutrophil degranulation, and platelet release and aggregation during ex vivo extracorporeal circulation. Fresh heparinized human blood was recirculated at 37 °C for two hours in a membrane oxygenator-roller pump perfusion circuit. Changes in platelet count, leukocyte count, platelet response to ADP, plasma p-thromboglobulin (BTG), kallikrein-C1 inhibitor complex (Kal-C1), C1-C1 inhibitor complex (C1-INH) and neutrophil elastase were measured before and at 5, 30, 60 and 120 minutes of recirculation in 30 studies at 0, 0.015, 0.03, 0.06 and 0.12 mgm/ml aprotinin. Without aprotinin plateletes decreased to 36 ± 12% of control at 5 min and increased to 56 ±13% at 120 min. Plasma BTG increased progressively to 2.10 mg/ml at 120 min. Aprotinin did not affect these values at a dose of 0.12 mgm/ml but did increase the sensitivity of platelets to ADP. Kal-Cl-INH and C1-C1-INH complexes increased progressively to 0.533 ± 0.135 µ/ml and 2.20 ± 1.17 n/ml respectively at 120 min without aprotinin. Kal-C1-INH complexes were completely inhibited at aprotinin concentrations of 0.03 mg/ml or greater. The increase in C1-C1-INH was not affected by any dose of aprotinin. Release of neutrophil elastase was partially but not completely inhibited at the highest dose of aprotinin and was 50% inhibited at 0.03 mg/ml concentrations. We conclude that aprotinin in high dose completely inhibits kallikrein-induced activation of neutrophils but does not inhibit the classical complement pathway. Aprotinin does not affect platelet adhesion or release but improves platelet function. Since this system does not generate plasmin, the effect on platelets may be mediated through neutrophil products. The data indicate that aprotinin partially preserves platelet function, totally inhibits contact activation, and partially inhibits neutrophil release, and thus attenuates the whole body inflammatory response.
*By Invitation 22. Venovenous Compares Favorably to Venoarterial Access for Extra-Corporeal Membrane Oxygenation in Neonatal Respiratory Failure
RALPH DELIUS, M.D.*, ROBERT H. BARTLETT, M.D., HARRY ANDERSON, III, M.D.*, ROBERT SCHUMACHER, M.D.*, MICHAEL SHAPIRO, M.D.*, TETSURO OTSU, M.D.* and JENNIFER HIRSCH* Ann Arbor, Michigan
Venoarterial ECMO with jugular and carotid cannulation has become standard treatment for severe respiratory failure in the newborn. Venovenous access has theoretical advantages, and is now possible using jugular cannulation with a double lumen catheter. We retrospectively compared 22 VV ECMO patients with 20 patients supported with traditional VA bypass. The two groups of patients were selected to be comparable in terms of diagnosis and severity of respiratory insufficiency. The diagnoses in both groups were limited to meconium aspiration syndrome or persistent pulmonary hypertension of the newborn. The average oxygenation index in both groups were similar (46.6 VV, 47.2 VA, p<0.05). Both VV and VA allowed flow rates > 100 ml/kg/min, which was adequate for gas exchange support. One patient required conversion of VV to VA bypass due to hemodynamic instability. The average time of support was 115 hours (range 24 to 338 hours) for VV ECMO and 134 hours (range 47 to 361 hours) for VA ECMO (p>0.05). The time to extubation after decannulation from ECMO was 133 hours (range 38 to 720 hours) for VV and 100 hours (range 27 to 192 hours) for VA (p>0.05). One patient supported with VA ECMO had an intracranial hemorrhage. There were no documented neurological injuries in the patients managed with VV ECMO. There were no deaths in either group. Venovenous ECMO through a double lumen cannula provides adequate respiratory support for neonates and pulmonary failure and avoids ligation of the common carotid artery.
*By Invitation 23. Successful Restoration of Cell Mediated Immune Response Following Cardiopulmonary Bypass by Immunomodulation
ANDREAS MARKEWLTZ, M.D.*, EUGEN FAIST, M.D.*, STEPHAN LANG, M.D.*, STEPHAN ENDRES, M.D.*, DIETMAR FUCHS, M.D.* and BRUNO REICH ART, M.D.* Munich, Germany Sponsored by: Norman E. Shumway, M.D., Stanford, California
The most common pathogens found in patients (pts) with septic multi organ failure after cardiopulmonary bypass (CPB) are opportunistic microorganisms indicating a depression of cell mediated immunity (CMI). It was therefore the purpose of our prospective randomized trial to study the immunologic changes due to CPB and the possible influence of im-munomodulation on CMI parameters. Patients and Methods: 32 male and 8 female pts with a mean age of 63.3 years undergoing coronary artery bypass grafting (n = 31) or valve replacement (n = 9) were included in the study. 20 pts received conventional therapy (Gr. 1), another 20 pts had additional im-munomodulatory treatment (Gr. 2) with the cyclooxygenase inhibitor in-domethacin (Indo) (3x50 mg i.v. daily for 5 d) and the thymomimetic substance thymopentin (TP-5) (50 mg s.c. 2 hours prior to operation, on d2 and d4). Indo blocks synthesis of prostaglandin E2 which downregulates CMI, TP-5 enhances T-lymphocytic reactivity. Immunologic screening was carried out preop., on dl, d3, and d7. CMI parameters studied included in vitro phenotyping of T-helper (T4) - and T-suppressor (T8) cells, mitogen induced lymphoproliferation (LP) and synthesis of interleukin (IL)-l, IL-2, tumor necrosis factor (TNF), and interferon (IFN)-gamma. Delayed type hypersensitivity (DTH) response to an antigen skin test battery served as in vivo parameter for CMI reactivity. Results: When compared to preop baseline data on dl, T4/T8 ratio, LP, IL-1, TNF, IL-2, and IFN-gamma synthesis were significantly reduced in controls (Gr. 1). Depression of CMI parameters persisted until d7; in addition DTH response was significantly impaired on d7. In Gr. 2 pts (Indo and TP-5 treatment) only LP were found to be significantly reduced on dl (Gr. 1 vs. Gr. 2: p< .05 for T4/T8 ratio, LP, IL-1, IL-2, TNF). On d3 all parameters studied had returned to preop baseline (Gr. 1 vs. G. 2: p<.05 for T4/T8 ratio, LP, IL-2, TNF, IFN-gamma) and remained normal until d7 (Gr. 1 vs. Gr. 2: p<.05 for T4/T8 ratio, LP, IL-2, IFN-gamma). DTH response showed no change on d7 as compared to preop. (Gr. 1 vs. Gr. 2: p<.05). Conclusions: 1. CMI response is seriously impaired following CPB. 2. Immunomodulation with Indo and TP-5 can successfully counteract the depression of CMI; this is - to our knowledge - the first time that a restoration of CMI response could be demonstrated following CPB.
*By Invitation 24. Redo Cardiac Surgery: Late Bleeding Complications From Topical Thrombin Induced Factor V Deficiency
BRIAN L. CMOLIK, M.D.*, JOEL A. SPERO, M.D.*, GEORGE J. MAGOVERN, M.D. and RICHARD E. CLARK, M.D. Pittsburgh, Pennsylvania
Bovine thrombin induced Factor V (FV) deficiency was
thought to be a very rare acquired coagulopathy with only one case documented
in the literature. We report the first series of 7 patients over a 2 year
period who developed this unique coagulopathy 1-2 weeks following
cardiopulmonary bypass. All patients had normal coagulation profiles
preoperatively. The coagulopathy was characterized by a markedly elevated
prothrombin time (PT) (26.6-69.9 sec.), an elevated activated partial
thromboplastin time (APTT) (68-M80 sec.), a positive lupus anticoagulant study
(7/7), and markedly decreased level of Factor V ( Admission PT(sec) Highest PT(sec) Lowest Factor V (% of
Normal) Outcome/ Complications 1
Redo CABG 13.5 69.9 <1 Alive/GI Bleeding 2
Redo CABG 12.7 47.6 <1 Alive 3
Redo MVR 13.6 30.6 6 Death/Bleeding 4
Redo MVR 13.5 64.2 4 Alive/Bleeding 5
AVR (S/P CABG) 11.3 31.2 8 Alive 6
Redo CABG 11.7 26.6 28 Alive 7
Asc. Ao. Repl. 12.9 39.6 2 Alive MEAN ± -SEM 12.7
± 0.3 44.2
± 6.5 7.1
± 3.6 The coagulopathy failed
to respond to intravenous Vitamin K, fresh frozen plasma or platelet
transfusions. Intravenous gamma globulin (IVIG), resulted in transient
improvement in abnormal PT, APTT, and FV levels. Four patients never
demonstrated clinical evidence of bleeding. Three patients (3/7) developed a
significant bleeding diathesis. One patient developed coagulopathic bleeding
which contributed directly to death by cardiac arrhythmia. One patient suffered
from spontaneous bleeding into surgical wounds which significantly prolonged
her hospital stay, and one developed minor gastrointestinal bleeding. Six of
seven patients were discharged from the hospital. Bovine
thrombin induced FV deficiency was previously unrecognized. This syndrome
should be suspected in patients undergoing redo cardiac surgery who develop marked
elevations in their PT 7-10 days after their exposure to bovine thrombin. The
resulting coagulopathy has produced bleeding complications and death. Current
treatment modalities are ineffective in correcting this coagulopathy, although
plasmapheresis may have a role in its management. These observations have
resulted in a more selective use of bovine thrombin as a topical hemostatic
agent at our institution. SPECIAL PRESENTATION - Los
Angeles Ballroom 75 Years Ago the Incredible Beginnings of Thoracic Surgery and
the AATS Andreas P. Naef, M.D., Pully-Lausanne, Switzerland 4:50 p.m. EXECUTIVE SESSION (Members Only) 7:00 p.m. 75th ANNIVERSARY DINNER/DANCE (Black Tie) *By Invitation TUESDAY AFTERNOON,
April 28, 1992 1:45
p.m. SIMULTANEOUS SCIENTIFIC SESSION
B - GENERAL THORACIC SURGERY - Beverly Hills Room 25. Intrathoracic Stomach: Presentation and
Results of Operation MARK S. ALLEN, M.D.*, VICTOR F. TRASTEK,
M.D., CLAUDE DESCHAMPS, M.D.* and PETER C. PAIROLERO, M.D. Rochester, Minnesota Between January
1, 1980 and December 31, 1990, 147 patients (96 females and 51 males) were
found to have an intrathoracic upside-down stomach. Median age was 69 years
(range 34-89). Signs and symptoms occurred in 141 patients (95.9%) and were
primarily obstructive. They included postprandial pain in 87 (59.2%) patients,
vomiting in 46 (31.3%), and dysphagia in 44 (29.9%). Only 23 (15.6%) presented
with reflux. Anemia was present in 31 (21.1%). One hundred
and twenty patients underwent elective surgical repair. The hernia was known to
be present for a median of 60 months (range 0-420) prior to operation. A
transthoracic uncut Collis-Nissen repair was done in 79 patients (65.8%), a
Belsey in 19 (15.8%), a transthoracic Nissen in 12 (10.0%), a transabdominal
Nissen in four (3.3%), and other procedures in six (5.0%). Twenty-three
patients (19.2%) had complications. There were no operative deaths. Median
follow-up of 116 patients (96.7%) was 46 months (range 1-139). Seventy-one
patients (61.2%) had excellent results, 38 (32.8%) good, six (5.2%) fair, and
one (0.9%) had poor results. Five patients had emergent operations for
suspected strangulation with one death. Of the remaining four, only two had
excellent results. Twenty-two other patients were followed for a median of 96 months
(range 12-268) with medical management. Two developed progressive symptoms and
one died following aspiration. We conclude
that patients with an intrathoracic upside-down stomach presenting with
obstructive symptoms should be repaired and that elective operation is safe and
effective. *By Invitation 26. Surveillance Endoscopy for Barrett's
Esophagus: Does It Help? JOHN M. STREITZ, JR., M.D.*, CHARLES W. ANDREWS, JR., M.D.* and F. HENRY ELLIS, JR., M.D. Burlington, Massachusetts Patients with
Barrett's esophagus (BE) are at increased risk for the development of
adenocarcinoma of the esophagus. Although endoscopic surveillance is commonly
practiced, it is not known whether it will improve post-resection survival
compared with patients whose carcinoma develops while not under surveillance.
This is our initial report of 19 patients in whom either high grade dysplasia
or invasive adenocarcinoma developed in a known pre-existing benign BE. Seventy-nine
cases with adenocarcinoma arising in BE were seen at our institution from
January 1973 to October 1991, 19 of whom were known previously to have had BE.
Surveillance endoscopy was carried out in these 19 patients at intervals
ranging from 1 month to 4 years, with a median interval of 6 months. Two
patients had a surveillance interval greater than 12 months and presented with
advanced tumors 3 and 4 years after their last endoscopy. All patients
underwent esophagogastrectomy except one who refused operation when severe
dysplasia was diagnosed and who returned 1 year later with an unresectable
carcinoma. Comparison of
the pathologic stages of these 19 tumors with those of the 60 patients not
under surveillance at the time of discovery showed a significant difference
with 11 (58%) vs 9 (15%) in stages 0 and 1, 4 (21%) vs 17 (28%) in stage 2, 4
(21%) vs 30 (50%) in stage 3, and 0 vs 4 (7%) in stage 4 (p= 0.002). Adjusted postoperative survival for 16 patients who underwent endoscopy
at least every 12 months and who underwent resection when advised was compared
with the group not under surveillance. The difference was significant with
survival at 1 year being 93% vs 67%, at 3 years 84% vs 36%, and at 5 years 67%
vs 22% (Tarone-Ware p = 0.02). Our data
strongly suggest that surveillance endoscopy allows early detection of
developing malignancy in BE and will improve long-term postoperative survival. *By Invitation 27. Epiphrenic Diverticulae, Why is Operation
Necessary? NASSER K. ALTORKI, M.D.*, DA VID B. SKINNER,
M.D. New York, New York Diverticulae
of the thoracic esophagus are uncommon disorders. The indications for surgical
intervention in asymptomatic or minimally symptomatic patients are unclear.
Among 20 patients referred over 20 years there were 6 males and 14 females with
a median age of 65 years. Two had had previous diverticulectomies. Dysphagia
was present in 9 (45%) and regurgita-tion in 11 (55%). Nine patients had severe
nocturnal cough with symptoms of aspiration. In two of these nine and in three
other patients (25%) pulmonary symptoms were the only manifestation of disease
with no or minimal esophageal symptoms. One patient was misdiagnosed as
bronchial asthma for several years, one had massive aspiration prior to a
hernia repair, one developed a bronchoesophageal fistula and lung abscess and 2
had severe persistent cough. All patients had a diagnostic barium esophagogram
and en-doscopy. Operation was performed in 17 patients while 3 declined. There
was one hospital mortality. Follow-up is complete on 17/19 patients until June 1991.
All operative survivors but one are asymptomatic. Of three patients refusing
surgery, one died from aspiration pneumonia, another died from a myocardial
infarction and one lives with severe dysphagia. Because of
the high incidence of aspiration (45%) and the potential for life threatening
pulmonary complications in some patients (15%), we conclude that operative
intervention should be undertaken in all patients with thoracic esophageal
diverticulae regardless of the presence or absence of symptoms. 2:45 p.m. INTERMISSION - VISIT EXHIBITS *By Invitation 3:15 p.m. SIMULTANEOUS SCIENTIFIC SESSION B
-GENERAL THORACIC SURGERY - Beverly Hills Room 28. Omentopexy and Early Postoperative
Corticosteroid in Clinical Lung Transplantation Toronto, Ontario Sponsored by: G. Alec Patterson, M.D., St.
Louis, Missouri Early success in clinical lung transplantation was
believed in part due to the technique of bronchial anastomosis, routine
bronchial omentopexy and avoidance of early postoperative corticosteroid. The
most recent 16 month consecutive experience of two programs with single (SLTx)
or bilateral (BLTx) lung transplant was compared to study the current
short-term effect of these perioperative strategies. In Center A, of 31
patients undergoing LTx, 29 had telescoped bronchial anastomoses, coverage of
the bronchus with local tissue only (no omentopexy), and routine perioperative
corticosteroid. In Center B, of 50 patients having LTx, 44 had end-to-end
bronchial anastomoses wrapped in omentum and received no routine perioperative
corticosteroid. These 29 patients from Center A and 44 patients from Center B
comprise the experience described below. SLTx BLTx Bronchial Anast. Biopsy Proven Operative 1 Yr. At Risk Dilatation Stent Acute Reject Mortality Act. Surv. Center A n = 29 4 25 54 2 1 14 5 81% Center B n = 44 21 23 67 1 - 19 4 82% In Center A, septic lung disease was the most
frequent indication (15 of 29 patients) whereas in Center B obstructive lung
disease was the most frequently encountered condition (24 of 44 patients).
Sepsis accounted for 3 of 5 early deaths in Center A (all due to resistant
pseudomonas cepacia infection in cystic fibrosis recipients) and for 2 of 4
perioperative deaths in Center B (one pseudomonas, one cadida). In Center A,
CMV prophylaxis was administered to all patients except negative recipients
receiving grafts from negative donors. CMV infection requiring treatment was
encountered in 5 of 29 patients at Center A in comparison to 23 of 44
recipients at Center B where only D+ and R- mismatches received prophylaxis.
Routine omentopexy is not required for successful lung transplantation. Early
postoperative corticosteroids do not
impair airway healing but neither do these agents appear to protect against
acute rejection episodes. While routine corticosteroids do not predispose the
recipient to CMV infection, their use may increase the likelihood of
postoperative bacterial sepsis. *By Invitation 29. Comparative Outcome of Heart-Lung and Lung Transplantation
for Pulmonary Hypertension ALAIN R. CHAPELIER, M.D.*, PHILIPPE G. DARTEVELLE, M.D.*, PASCAL R. VOUHE, M.D.*, JACQUES CERRINA,
M.D.*, FRONCOIS LE ROY LADURIE, M.D.* and GERALD SIMONNEAU, M.D.* Le Plessis Robinson, France Sponsored by: Jean DesLauriers, M.D., St.
Foy, Quebec While several lung transplantation (LT) procedures
have been developed during the recent years, the most accurate for pulmonary
hypertension (PHT) remains controversial. Out of a total series of 72 LT
performed by the same team since 1986, 27 were for end-stage lung vascular
disease (primary PHT, n = 22; chronic pulmonary embolism, n = 3; histiocytosis
x, n = 2). There were three groups according to the
transplantation procedure: Group A, with heart-lung transplantation (HLT), 19
patients aged 37 ± 11 years, operated between 1986 and 1991; Group B, with
en-bloc double lung transplantation (DLT), 7 patients aged 36 ± 8 years,
operated since October 1990; Group C, with single lung transplantation (SLT), 1
patient aged 35 years operated in December 1990. In Group B the airway
anastomosis was performed by double proximal bronchial anastomoses which
resulted in 2 cases in stenosis corrected with stents; the associated ASD was
closed and correction of major pulmonary artery (PA) size discrepancy was
achieved using anastomosis of the recipient's left PA to the donor's main PA. In Group A, the cumulative survival rate is
78% and 53% at 1 and 4 years respectively (4 post-operative deaths). In
Group B, 1 patient died in postoperative course and in Group C, the patient is
alive 10 months later. Hemodynamic values are similar in Groups A and B. HLT (ht-lung) DLT (double) SLT (single) Pre-op. Post-op. Pre-op. Post-op. Pre-op. Post-op. P.A.P.?
(mm Hg) 66.2 ± 17.4 20.6 ± 3.3 7 1.4 ± 22.7 19.5 ± 3.3 80 42 C.I.
(1/m2) 2.1 ± 0.4 3.3 ± 0.7 1.9 ± 0.3 3.3 ± 0.7 1.9 3 P.V.R.
(Wood U.) 27.4 ± 13.6 3.2 ± 1.4 32.4 ± 8.2 3.1 ± 1.6 38.4 8 The respiratory functionn tests are similarly
favorable in Groups A and B. Three patients in Group B developed early and
reversible left ventricle dysfunction. The SLT patient had difficult
hemodynamic post-operative course and six months later is providing high PAP
levels (27 mm Hg) and maximum work load of 60 W compared with a mean 120 W in
Groups A and B. Conclusion:
1) En-bloc DLT should be preferred to HLT being followec by immediate right
ventricular function recovery and avoided of cardiac specific graft
complications despite transient left ventricle dysfunction. 2) DLT should also
be preferred to SLT, procedure complicated with a critica post-operative course
and with modest functional results. *By Invitation 30. Obliterative
Bronchiolitis After Lung or Heart-Lung Transplantation for Primary Pulmonary
Hypertension SARA J. SHUMWAY, M.D.*, MARSHALL I. HERTZ,
M.D.*, JOSE JESSURUN, M.D.*, RAOUF NAKHLEH, M.D.*, MICHAEL PETTY, R.N., B.S.N.* and R. MORTON BOLMAN, III, M.D. Minneapolis, Minnesota Since the advent of heart-lung (HLT) and lung (LT)
transplantation at the University of Minnesota in May 1986, 24 HLT, 26 SLT, 1
double lung, and 3 bilateral SLT have been performed. Nine patients underwent
HLT and four SLT for primary pulmonary hypertension (PPH). Of these 53
patients, 13 have developed obliterative bronchiolitis for an overall incidence
of 24.5%. Among these 13 patients with OB, seven have died, one has undergone
successful bilateral SLT after a SLT for PPH, and one died following an
unsuccessful attempt at SLT following HLT for PPH. Five are living with OB on
medical management; one is awaiting retransplantation and one is considering
retransplantation. Of patients transplanted for PPH, 6 of 13 (46%) have
developed OB (2 of 4 after SLT, 4 of 9 after HLT). The incidence of OB
following transplantation for etiologies other than PPH is 17.5% (7 of 40 patients).
Only one of 7 patients (14%) with alpha-1 antitrypsin deficiency developed OB
after SLT, and only one of the 9 heart-lung recipients (11%) presenting with
Eisenmenger's complex has developed OB. Compared to the incidence of OB
following transplantation for other etiologies, the rate of OB after
transplantation for PPH does not reach statistical significance, however the
trend definitely suggests that patients with PPH may be at increased risk to
develop OB after lung or heart-lung transplantation. Furthermore, the
disease-free interval before the onset of OB is longer when a HLT is done in
contrast to a single lung transplant for PPH (mean of 18 months for 4 patients
versus mean of 7 months for 2 patients, respectively). Given this trend toward
the increased development of OB following transplantation for PPH, we believe
that replacement of both lungs may provide the patient transplanted for PPH a
longer disease-free interval from obliterative bronchiolitis than replacement
of a single lung. *By Invitation 31. A
Decade of Pediatric Cardiac Transplantation and the Impact of FK506 BARTLEY P. GRIFFITH, M.D., JOHN M. ARMITAGE,
M.D.*, FREDERICK J. FRICKER, M.D.*, THOMAS E. STARZL, M.D., Ph.D.* Pittsburgh,
Pennsylvania The application of lung transplant technology
to the pediatric population was a natural extension of the success realized in
our adult transplant program which began in 1983. Fourteen pediatric patients
(age range 3 to 15 years) have undergone heart-lung (8) or double-lung (7)
transplantation (1985-1991). The etiology of end stage lung disease in this
pediatric group was primary pulmonary hypertension (4), congenital heart
disease (4), cystic fibrosis (2), pulmonary arteriovenous malformation (2),
graft versus host disease (1) and desquamative interstitial pneumonitis (1).
There were 3 perioperative deaths and no late deaths: sepsis (1),
cytomegalovirus (CMV) (1) and donor organ dysfunction (1). The overall survival
was 78% with follow-up of 6 years (2), 4 years (1), 3 years (1), 2 years (1), 1
year (1), and 6 months (5). Immunosuppression in our first 9 patients was
cyclosporine based therapy with azathioprine, steroids and rabbit antithymocyte
globulin (RATG). Encouraged by the dramatic immune advantage' and paucity of
side effects in the FK506 trial in pediatric cardiac transplantation we have
initiated the trial of FK506 with azathioprine and low dose steroids in the
pediatric pulmonary transplant recipients. The last 5 lung transplant
recipients' immunosuppression has been FK 506 based triple drug therapy without
antilymphocyte agents. Additionally one of the recipients was switched from
cyclosporine to FK506 due to severe hirsutism and hypertension which developed
three months post-transplant. Rejection was diagnosed by pulmonary function
tests (PFT), donor specific primed lymphocyte response and lung biopsy. Nine of
11 patients (80%) were treated with intravenous steroids for episodes of acute
rejection, however, only 2/11 recipients (18%) had chronic rejection and 1/11
patient (9%) had significant obliterative bron-chiolitis. Lung functions,
measured by serial home and hospital based PFT's, have remained good (average
FEV1 90%predicted) in all the children. Complications in the group have
been few: phrenic paresis 2/11, bronchial stenosis 1/11, and post-transplant
lymphoproliferative disease 1/11. Viral infections represented a constant
threat to the pediatric lung recipient: CMV (4), Epstein Barr Virus (2), and
Coxsackie virus (1). Since 1989 all lung recipients received intravenous
ganciclovir for 2-4 weeks post transplant and oralacyclovir
for six months. This anti-viral therapy has reduced the incidence of CMV to 1
of the last 7 recipients. Cardiac rejection and graft coronary arteriopathy
have not been observed in the heart-lung recipients. Airway management, the
diagnosis of rejection, lung biopsy and follow-up have posed unique problems in
the pediatric age group. However, pulmonary transplantation holds real hope for
children afflicted by both primary and secondary lung disease. SPECIAL PRESENTATION - Los
Angeles Ballroom 75 Years Ago the Incredible
Beginnings of Thoracic Surgery and the AATS Andreas P. Naef, M.D., Pully-Lausanne, Switzerland 4:50 p.m. EXECUTIVE SESSION (Members Only) 7:00 p.m. 75th ANNIVERSARY DINNER/DANCE (Black Tie) *By Invitation TUESDAY AFTERNOON, April 28, 1992 1:45 p.m. SIMULTANEOUS SCIENTIFIC SESSION C -
CONGENITAL HEART DISEASE - Santa
Monica Room 32. Surgical
Treatment of Coarctation of Aorta in Infants L. W. ERNEST van HEURN, M.D.*, MARC R.
DeLEVAL, M.D.*, JAROSLAV F. STARK, M.D., CM. WONG*, O.J. SPIEGELHALTER, M.D.* and London, England Despite advances in recent years there remains
controversy over the appropriate surgical treatment of coarctation in infants.
Thus we reviewed our recent experience. One hundred fifty-one infants less than three months
of age underwent repair of coarctation between 1985 and 1990. In 25% there was
hypoplasia of the isthmus and in 33% of the transverse arch. Surgical therapy
used was subclavian flap angioplasty (SFA) in 15, resection with a traditional
end to end anastomosis (E-E) in 43 and resection with an extended end to end
anastomosis into the arch (EE-EA) in 77. In 30 the extension was proximal to
the origin of the left carotid artery (REE-EA). Other procedures were used in
16. Mortality (13 early and 12 late deaths) was related
to the presence of associated major heart defect, to preoperative resuscitation
and to direct postoperative gradient over the arch. The gradient was
significantly lower after EE-EA and REE-EA if there was a hypoplastic isthmus
and after REE-EA if the transverse arch was hypoplastic. Actuarial freedom from
recoarcta-tion at 4 years was 57% (CL 28%-78%) after SFA, 77% (CL 60%-87%)
after E-E, 83% (CL 66%-92%) after EE-EA and 96% (CL 77%-100%) after REE-EA. We conclude that the extended end to end anastomosis
and radical end to end anastomosis offer the best prognosis to treat
coarctation in infants irrespective of the arch morphology. *By Invitation 33. Results of Surgical Repair of Supravalvular
Aortic Stenosis in Children JOHN L. MYERS, M.D. and JOHN A. WALDHAUSEN, M.D. Hershey, Pennsylvania From 1975 to 1991 thirteen patients (7 female, 6
male) have undergone surgical correction of supravalvular aortic stenosis.
Preoperative catheteriza-tion demonstrated left ventricular to aortic arch
gradients of 25 to 110 mmHg (mean 62 mmHg). The patients were operated on at 2
days to 14 years of age (mean 6 yrs). Repair was accomplished by one of two
techniques. 1) A bifurcated patch extending from the ascending aorta down into
the right and non-coronary sinuses of valsalva (N = 7) or 2) transection of the
aorta at the level of stenosis and incising into all three sinuses of valsalva;
counter incisions were made in the distal ascending aorta, allowing advancement
of these flaps into each sinus of valsalva (N = 6). This "Y" to "V" flap
advancement enlarges the supravalvular area with autologous aortic tissue and
eliminates the stenosis. The cross-clamp time was 22 to 104 minutes (mean 67
min). The mean reduction in gradient postoperatively was 47 mmHg. There was one postoperative death (8%) in a two day
old infant who had complete relief of her stenosis but died secondary to severe
hypertrophic car-diomyopathy. The average postoperative length of stay was
seven days. There are no late deaths. One patient had successful reoperation
for residual stenosis distal to the aortic patch. Follow-up has been one month
to 11.7 years (mean 3.4 yrs). Echocardiograms performed at most recent
follow-up demonstrate mild aortic insufficiency (AI) in five patients, and
trace or no AI in six patients. Eight patients have a gradient less than 25
mmHg, and three have gradients of 25 to 40 mmHg. All three of these patients had
the bifurcated patch technique. The technique of aortic division and advancing
aortic flaps into all three sinuses of valsalva produces a more anatomic repair
and has provided good relief of supravalvular aortic stenosis and deserves
broader use. *By Invitation 34. Management of Severe Subaortic Stenosis,
Ventricular Septal Defect and Aortic Arch Obstruction in the Neonate ARA K. PRIDJIAN, M.D.*, EDWARD L. BOVE, M.D., L. LUANN MINICH, M.D.*, FLAVIAN M. LUPINETTI,
M.D.* and A. REBECCA SNIDER, M.D.* Ann Arbor, Michigan Neonates with ventricular septal defect (VSD) and
aortic arch obstruction frequently have severe subaortic stenosis (SAS)
secondary to posterior deviation of the infundibular septum. The optimal method
of repair is uncertain and the use of conduits to bypass the obstruction has
been recommended because direct relief of the outflow tract obstruction through
the standard transaortic approach is difficult. From September 89 to August
91, 6 neonates and VSD, coarctation (n = 4) or interrupted aortic arch (n = 2)
and severe SAS underwent repair using a new operative technique. The
infundibular septum was partially removed via the right atrium by resecting the
superior margin of the VSD up to the level of the aortic annulus. The resulting
enlarged VSD was then closed with a patch to widen the subaortic area. In each
patient, the aortic arch was repaired by direct anastomosis. The patients
ranged in age from 4 to 28 days (median, 11 days) and in weight from 1.3 to 5.4
kg (mean, 3.2 kg). The preoperative ratio of the diameter of the left
ventricular outflow tract to the descending aorta in systole was 0.5 ± 0.1 mm
(SD) and ranged from 0.42 mm to 0.65 mm. All patients survived operation with
one late death 3 months after operation from noncardiac causes. The survivors
remain well from 1 to 12 months following repair (mean, 6 months). All are in
sinus rhythm and none has an important residual arch gradient or VSD. No
patient has residual SAS although one has significant valvar aortic stenosis
(Doppler gradient, 85 mmHg). Mild aortic regurgitation is present in one
patient. This series suggests that in neonates with VSD and severe SAS
secondary to posterior deviation of the infundibular septum, direct relief can
be satisfactorily accomplished from a right atrial approach. This method
provides effective widening of the left ventricular outflow tract and is
superior to palliative techniques or conduit procedures. 2:45 p.m. INTERMISSION - VISIT EXHIBITS *By Invitation 3:15 p.m. SIMULTANEOUS SCIENTIFIC SESSION C -
CONGENITAL HEART DISEASE - Santa Monica Room 35. Neonatal Repair of Truncus Arteriosus ALDO R. CASTANEDA, M.D., FRANK L. HANLEY,
M.D.*, JOHNE. MAYER, JR., M.D. and RICHARD A. JONAS, M.D. Boston, Massachusetts Between 1/87 and 10/91 patients with truncus arteriosus were surgically
managed. 57 of 60 patients (95%) underwent primary repair and 44 of 60 (73%)
were less than 3 months of age at repair. Among these 44 patients there has
been a recent trend towards earlier repair: # Cases Age (days) Hospital Deaths 1987 5 49 0 1988 5 47 2 1989 12 40 2 1990 11 29 3 1991 11 12 1 Three of 6
patients (50%) with associated interrupted aortic arch and 4 of 8 patients
(50%) with significant truncal valve dysfunction died. These lesions therefore
were associated with 7 of 8 (88%) of the hospital deaths. Other important
associated lesions, including branch pulmonary artery stenosis or anomalous
origin, multiple VSDs, anomalous pulmonary venous return, and coronary artery
anomalies were present in 9 additional patients and were not associated with
hospital mortality. Over the past two years, in association with early neonatal
repair, there have been no cases of post operative pulmonary hypertensive
crisis and mean pulmonary artery/right ventricular pressure has been uniformly
below 30% systemic pressure. Medium term follow-up (2 mo - 24 mo) was available
in 22 of 36 hospital survivors and revealed no further mortality. Conclusions:
Interrupted aortic arch and truncal valve dysfunction remain important risk factors
for surgical death. In the absence of these two associated lesions, truncus
arteriosus can be repaired with excellent surgical outcome in the early
neonatal period (29/30 survivors, 97%). Repair in the early neonatal period
appears to reduce the incidence of post operative pulmonary hypertension and
pulmonary vascular liability. *By Invitation 36. Results of a Protocol of Early Repair for
Truncus Arteriosus EDWARD L. BOVE, M.D., FLAVIAN M. LUPINETTI,
M.D.*, ARA K. PRIDJIAN, M.D.*, JON N. MELIONES, M.D.*, LOUISE B. CALLOW, R.N.* and A. REBECCA SNIDER, M.D.* Ann Arbor, Michigan Although the mortality for repair of truncus
arteriosus has decreased, routine repair in the neonate has not been widely
adopted. Since 1986, we have followed a protocol of early repair, generally
within the first month of life. From 1/86 to 10/91, 37 patients underwent
repair of truncus arteriosus. Ages ranged from 1 day to 7 months (median, 13
days) and weights from 1.9 to 5.4 kg (mean, 3.2 kg). Repair was done beyond 30
days of age in only 7 patients due to late referral (6) or noncardiac problems
(1). Associated lesions were: interrupted aortic arch (n = 4), nonconfluent
pulmonary arteries (n = 3), infracardiac TAPVR (n = l) and hypoplastic
pulmonary arteries (n = 3). Truncal valve regurgitation was absent in 18
patients, mild to moderate in 14 and severe in the remaining 5 patients.
Truncal valve replacement was performed in the 5 patients with severe
regurgitation, 3 of whom also had transvalvar gradients exceeding 30 mmHg. The
truncal valve was replaced with a mechanical prosthesis in 2 patients and with
a homograft in 3. Right ventricle to pulmonary artery reconstruction was
performed with homograft conduits in 32 patients (range, 8 to 15 mm), valved
porcine conduits in 4 (range, 12 to 14 mm) and with a nonvalved gortex tube in
1 patient (10 mm). Actuarial survival at 1, 6 and 12 months was 84%, 78% and
78%, respectively. There was 1 death among the 7 patients with interrupted arch
or nonconfluent pulmonary arteries. Late death occurred in 3 patients (one
noncardiac) with no additional mortality after the fourth postoperative month.
Reoperations were required in 4 patients for conduit obstruction (3 months to
3.5 years after initial repair) and in 2 for residual VSD. Despite the high
incidence of major associated anomalies, early repair has resulted in excellent
survival. We continue to recommend repair promptly after presentation,
optimally within the first month of life. *By Invitation 37. Anatomical Subtype of Hypoplastic Left
Heart Syndrome Influences Survival After Palliative Reconstruction RICHARD A. JONAS, M.D., DOLLYHANSEN, M.D.*, NANCY COOK, Ph.D.* and DAVID WESSEL, M.D.* Boston, Massachusetts The mortality of the reconstructive surgical
approach to hypoplastic left heart syndrome (HLHS) has remained high in many
centers, including those consistently achieving extremely low mortality rates
for virtually all other congenital heart anomalies. Accordingly, interest in
neonatal heart transplantation for HLHS has strengthened though widespread
application is limited by donor supply. We conducted a retrospective study of
78 consecutive patients undergoing palliative reconstructive surgery for HLHS
between 1983 and 1991 to identify predictors of mortality which might enable
more appropriate triage of patients to either reconstruction or
transplantation. Of the 78 patients, 29 had aortic atresia, mitral atresia
(AA,MA) (37%), 18 had aortic stenosis and mitral stenosis (AS,MS) (23%), 20 had
aortic atresia and mitral stenosis (AA,MS) (26%), and 11 had other variants
(14%). Aortic reconstruction was with a homograft gusset in 28 (36%), a
homograft tube graft in 9 (12%), a synthetic tube in 29 (37%) and other forms
of reconstruction in 12 (15%). A right sided Blalock shunt was used in 68 (87%)
and a central shunt in 10 (13%). One patient was lost to follow-up to August,
1991. There were 29 hospital deaths (37%). The product-limit (PL) survival
estimate among hospital survivors was 25% at five years. Analysis of hospital
deaths revealed no strong predictors of hospital mortality though there was a
suggestion that subgroup AA,MS may be at greater risk of hospital death
irrespective of surgical procedure (p=0.06). Age at surgery, ascending aortic
diameter, shunt type, method of aortic reconstruction and year of surgery did
not influence outcome. Anatomical subtype was a predictor of late survival with
a PL survival estimate at 3 years of 11 % in the AA,MA group with a trend to
worse survival with a very small ascending aorta, of 25% in the AA,MS subgroup
and of 76% in the AS,MS subgroup (logrank p = 0.03). This also held true (p =
0.05) when analysis was undertaken according to survival to next procedure
following neonatal palliation, thereby eliminating the mortality of the Fontan
operation which was evolving in this time frame. We conclude that patients with AA.MA in particular
those with an ascending aortic dimension of less than 2 mm, may be better
served by heart transplantation than a reconstructive approach. The longterm
outlook for the subgroup with aortic stenosis and mitral stenosis, however,
would appear to support a reconstructive approach for this subgroup. We
speculate that there are inherent limitations of the current neonatal procedure
reflected in a high uniform early mortality over time and between institutions
which should be addressed by innovative surgical or ancillary procedures. *By Invitation 38. High Dose Steroids Prevent Placenta!
Dysfunction After Fetal Cardiac Bypass JOSEPH F. SABIK, M.D.*, FRANK L. HANLEY, M.D.*, MARKUS K. HEINEMANN, M.D.* and RENATO S. ASSAD, M.D.* Sponsored by: Aldo R. Castaneda, M.D., Boston, Massachusetts Surgical
treatment of certain congenital heart lesions in utero may have therapeutic
advantage over post natal repair or palliation. To perform fetal heart surgery
a method to support the fetal circulation will need to be developed. Early
experimental attempts at fetal cardiac bypass were unsuccessful secondary to
increased placental vascular resistance during and after fetal cardiac bypass.
This increase in placental vascular resistance led to decreased placental blood
flow, fetal asphyxia and death. Our laboratory has demonstrated that the
administration of indomethacin (a cyclooxygenase inhibitor) during fetal cardiac
bypass prevents this increase in placental vascular resistance during and after
fetal cardiac bypass. The mechanism by which indomethacin achieves this effect
is either by inhibiting the production of a placental vasoconstrictive
prostaglandin, or by diverting substrate from the cyclooxygenase pathway to the
lipooxygenase pathway, thereby increasing production of a placental
vasodilating leukotriene. To determine which of these mechanisms is responsible
for preventing the increase in placental vascular resistance after fetal
cardiac bypass, we inhibited both prostaglandin and leukotriene synthesis at
the phospholipase stage with high dose steroids. Fourteen fetal lambs were used
in the study. Six animals received indomethacin (3 mg/kg), four animals received
high dose steroids (solumedrol 50 mg/kg), and four animals were used as
controls. Observations were made during a one hour pre-bypass period, a thirty
minute bypass period, and a two hour post bypass period. Placental blood flow
and placental vascular resistance were calculated at four times during the
experiments: Pre-Sternotomy; Post-Sternotomy; during bypass at thirty minutes;
and thirty minutes after cessation of bypass. Similar to
indomethacin, high dose steroid administration during fetal cardiac bypass,
prevents the rise in placenta! vascular resistance and preserves placental
blood flow during and after fetal cardiac bypass. This study clearly
demonstrates that the production of a placental vasoconstrictive prostaglan-din
is responsible for the increase in placental vascular resistance and decrease
in placental blood flow observed after fetal cardiac bypass. SPECIAL PRESENTATION - Los
Angeles Ballroom 75 Years Ago the Incredible
Beginnings of Thoracic Surgery and the AATS Andreas P. Naef, M.D., Pully-Lausanne, Switzerland 4:50 p.m. EXECUTIVE SESSION (Members Only) 7:00 p.m. 75th ANNIVERSARY DINNER/DANCE (Black Tie) *By Invitation |
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