MONDAY AFTERNOON, APRIL 16, 1973

2:00 P.M. Scientific Session

Regency Ballroom

9. Diaphragm Pacing by Radiofrequency Transmission in the Treatment of Chronic Ventilatory Insufficiency: Present Status

W. W. L. GLENN, W. G. HOLCOMB,* J. HOGAN,*

I. MATANO,* J. B. L. GEE,* E. K. MOTOYAMA,* C. S. KIM*

and R. A. POIRIER,* New Haven, Connecticut

The indications for, complications of and long term results of diaphragm pacing in IS patients with chronic ventilatory insufficiency will be reported. In 12 patients the respiratory center was affected (Ondine's curse); in 3 patients there was partial or complete severance of the upper cervical cord. The diaphragm pacemaker consists of a radiowave generator transmitting programmed signals via an antenna to a subcutaneous receiver connected to bipolar electrodes around one or both phrenic nerves. Receiver failure, initially troublesome, appears to have been corrected. Nerve fatigue is evident after 10-12 hours of continuous unidirectional stimulation but its onset may be delayed by utilizing a bidirectional stimulus.

In one patient pacing failed after 2 weeks. In the remaining patients adequate ventilation of the lungs, as evidenced by spirometry, normal blood gas concentration and Xenon 133 diffusion studies, has been achieved up to 44 months without evidence of injury to the phrenic nerve; the phrenic nerve stimulation threshold rose initially but stabilized within 6 months usually at between 1 and 2 milliamperes. Right heart failure and pulmonary hypertension, when present, improved during diaphragm pacing. Evidence to date indicates that pacing of the diaphragm is an effective, practical and reasonably safe technique for long term partial or complete ventilatory support.

*By invitation

10. Development of an Implantable Artificial Lung

ARTHUR PALMER,* JOHN COLLINS* and LOUIS R. HEAD,

Chicago, Illinois

A membrane oxygenator, which can be implanted in the chest, has been developed to function as an artificial lung. It operates at pulmonary artery pressure and requires no external power source for ventilation. Silastic capillary tubes function as the membrane surface. These are manifolded in parallel into modules containing 2288 to 6270 individual tubes. The modules are then sealed in a Silastic ventilating envelope which is connected to an artificial bronchus. Blood flows through the capillary tubes and the gas in the ventilating envelope is continuously changed by the normal motion of the dogs chest.

Ten artificial lungs have been implanted in dogs. Blood flow through the prosthesis ranged from 80-260cc/min at mean pulmonary artery pressures of 10-25mm. of Hg. Oxygen transfer ranged from 15-23cc/min/M2 at physiologic levels of pO2, pCO2 and ph.

The major problem remaining is prevention of intravascular coagulation in the artificial lung. Regional heparinization is presently used and various antithrom-bogenic surface treatments are under investigation.

*By invitation

11. Delayed Sequelae of Penetrating Cardiac Wounds

P. N. SYMBAS, DAVID A. DiORIO,* D. H. TYRAS,*

R. E. WARE* and CHARLES R. HATCHER, Jr.,

Atlanta, Georgia

In order to determine the course and sequelae of penetrating cardiac wounds, the cases of 76 patients with such injuries treated at Grady Memorial Hospital from July 1964 through June 1972 were reviewed. Of these 76 patients, 56 survived the immediate postinjury period with no further mortality attributable to their injury during an average 19 month follow-up period. A variety of anatomic and physiologic sequelae of the cardiac wounds were encountered, including 5 ventricular aneurysms (3 pseudo, 1 true, and 1 undefined aneurysm), 3 ventricular septal defects, 3 instances of valvular incompetence (2 mitral, 1 pulmonic), 2 aortopulmonary fistulae and 2 instances of bullets retained within the interventricular septum. With the exception of the 2 patients with ventricular septal defects and both patients with aortopulmonary fistulae, none of these patients were more than mildly symptomatic and most were totally asymptomatic. Operative intervention has been carried out without mortality and with excellent results in the 4 patients with marked symptoms (2 VSD and both AP fistulae) and in 4 patients with ventricular aneurysms (3 pseudo and 1 true).

This experience re-emphasizes the need for close follow-up of patients sustaining penetrating cardiac wounds and repair of the delayed sequelae of such wounds when either hemodynamically significant or potentially dangerous to the patient.

*By invitation

12. Air Embolism Following Penetrating Lung Injury

ARTHUR N. THOMAS,* San Francisco, California

Sponsored by Benson B. Roe

The literature does not mention the occurrence of air embolism after penetrating lung injury. Nevertheless we have documented coronary air embolism after penetrating lung injury in three patients. We believe that this was responsible for difficulty in resuscitating the patient in one instance and resulted in death in two.

In order to evaluate the mechanism and significance of air embolism penetrating lung injuries were created in 14 anesthetized dogs. A polyethylene shunt between the aortic root and femoral vein was used as an air bubble trap and detector. The lung was penetrated with a #22 scalpel blade. Air immediately appeared in the shunt in 10 of 14 dogs. Airway, pulmonary artery, right ventricle, left atrial and femoral arterial pressures were measured in animals receiving controlled ventilation.

Air caused rapid death from coronary embolism in 6, and caused hemody-namic changes that spontaneously ceased in 4. Lung injury produced no detectable air embolism in 4 dogs. A communication between the airway, pulmonary artery and pulmonary vein was shown in all lung wounds. The sequential hemodynamic changes measured were left ventricular failure, left atrial hypertension, pulmonary arterial hypertension and systemic hypotension.

The conclusion is that air embolism is a potential hazard following lung wounds. It is most apt to occur in patients who are in shock and require positive pressure ventilation.

*By invitation

13. The Role of Bronchial Brushing on the Decision for Thoracotomy

J. J. FENNESSY* and C. F. KITTLE, Chicago, Illinois

More than 600 transcatheter or bronchial brush biopsies have been performed at The University of Chicago Hospitals between 1965 and 1972. Tissue thus secured was examined histologically and cytologically, and cultured for fungus and bacteria. In most of these patients the indication for the procedure was the presence in the lung of a lesion suspected to be malignant. Flexible fiber optic bronchoscopy has been done for the past 3 years in these patients.

This presentation is a retrospective analysis of the clinical and radiologic data available on patients subjected to bronchial brush biopsy and flexible bronchos-copy to determine to what extent, if any, the results of the procedure influenced the surgeon's decision to operate.

These patients have been analyzed by reviewing the clinical data pre-brushing to determine if the surgeon would advise thoracotomy. A retrospective analysis was also done by both authors to determine if brushing was helpful in the overall management.

Definite indications for brushing have been established: the possibility of inflammatory disease and a need for culture material, the question of metastatic disease with multiple nodules, and the opportunity of obtaining a tissue diagnosis for x-ray therapy when other conditions precluded operation. In many instances "brushing" has been of supplemental interest only without decision-making importance.

*By invitation

14. Parasternal Mediastinotomy-A Useful Adjunct in the Diagnosis of Chest Disease

PHILIP C. JOLLY,* LUCIUS D. HILL, THOMAS WEST*

and PETER LAWLESS,* Seattle, Washington

One hundred consecutive cases of parasternal mediastinotomy have been compared to 240 cases of mediastinoscopy. Distant metastases were not present in these patients to contraindicate thoracotomy or allow easy tissue diagnosis. There was no mortality and morbidity was low after both procedures. Sixty-eight percent of the patients had carcinoma of the lung. In those patients with lung cancer tissue diagnosis was obtained by mediastinotomy in 69% and by mediastinoscopy in 32%. Undifferentiated tumors yielded a higher diagnostic return in both groups. Mediastinotomy proved superior to mediastinoscopy in evaluating patients for resectability. Resectability rates at thoracotomy correlated accurately with the findings at mediastinotomy and mediastinoscopy. Of the malignant cases, thoracotomy was avoided in 62% by mediastinotomy and in 30% by mediastinoscopy.

Parasternal mediastinotomy is a simple, versatile procedure. Lung biopsies were obtained in 22 patients yielding a diagnosis in a variety of chest diseases. Therapeutic procedures such as pericardial window, excision of pericardial cysts and placement of epicardial electrodes for pacemaking are possible through this incision.

*By invitation

15. Delayed Cutaneous Hypersensitivity Reactions to Tumor Antigens and to Non-Specific Antigens: Prognostic Significance in Patients with Lung Cancer

SAMUEL A. WELLS,* Durham, North Carolina

JAMES F. BURDICK* and CHRISTINE CHRISTIANSEN,*

Bethesda, Maryland, WILLIAM L. JOSEPH,* WALTER G.

WOLFE* and PAUL C. ADKINS, Washington, D.C.

Oncogenesis is favored by an environment of depressed immunity, but there are few studies in humans correlating both general immunological status and reactivity to tumor specific antigens with the patient's clinical course.

Delayed cutaneous hypersensitivity reactions (DCHR) to bacterial antigens (mumps, Candida and streptokinase-streptodornase) and to a previously unen-countered antigen, dinitrochlorobenzene (DNCB), were evaluated in 100 ambulatory patients, 75 with lung cancer and 25 with benign lung disease. Eighteen cancer patients were also tested with membrane antigen extracts (MAE) of autologous tumor tissue.

Twenty-four patients with benign disease had positive DCHR to both bacterial antigens and DNCB. In the 75 cancer patients 72 developed DCHR to bacterial antigens, but reactivity to DNCB was markedly depressed with only 40 patients reacting and in 12 patients with non-resectable disease only 2 reacted. Eight of 18 patients developed DCHR to autologous MAE of lung tumor, but not to normal lung. Seven of these patients were well at eight months, while only 3 patients with negative DCHR to tumor MAE were alive without recurrent disease.

These data demonstrate that in lung cancer patients, a poor prognosis is associated with a depressed immune recognition of DNCB and negative cutaneous reactivity to autologous tumor MAE.

*By invitation

16. Segmental Resection for Lung Cancer-A 15-Year Experience

ROBERT J. JENSIK, L. PENFIELD FABER, FRANK J.

MILLOY* and DAVID O. MONSON,* Chicago, Illinois

One hundred fourteen patients with primary lung cancer underwent segmental resective surgery over the past 15 years. The patients were placed in the following groups:

I. In 14 patients, previous contralateral resective surgery had been carried out;

II. In 26 patients, the procedure was done for palliation;

III. In 74 patients, the resection was considered as a definitive curative operation.

Four patients of Group I survived more than two years with the longest survivor still alive seven plus years later.

Only five patients survived more than two years in the palliative group, the longest attaining a five-year survival.

A 55% five-year survival calculated by actuarial method was achieved in Group III. This declined to 2 1% over the 15-year period.

Tumor histology and location, the type of segmental procedures, and factors influencing the decision for limited resection will be discussed.

An operative mortality of 5% to 6%with a 55% five-year survival suggests that segmentectomy may be the procedure of choice when indicated.

*By invitation