Louis L. Smith

Experimental Whole-organ Transplantation of the Liver and of the Spleen°

THE RAPIDLY growing experience in experimental homotransplantation is largely based on observations of the skin, kidney, blood and bone marrow. These studies have been the pioneer ones for reasons that are clear historically: skin for its availability; kidney for its significance as a paired organ with a simple vascular pedicle, the biochemical product of which can easily be measured; blood for its circulatory support; and bone marrow for its use as a replacement tissue after hematopoietic destruction either in cancer

Transduodenal sphincteroplasty (not sphincterotomy) for biliary and pancreatic disease. Indications, contraindications, and results.

Abstract 1. 1. The anatomy and physiology of the constricting mechanisms at the lower end of the common duct are reviewed. 2. 2. The need for complete elimination of these operations are demonstrable by postcertain cases of recurrent pancreatitis and in problems of extrahepatic biliary obstruction has been stressed. 3. 3. Elimination of these sphincteric mechanisms requires sphincteroplasty and cannot be accomplished by sphincterotomy. 4. 4. Key points in the technic of sphincteroplasty are outlined. 5. 5. The importance of a pancreatic ductogram in selecting the surgical approach in patients with recurrent pancreatitis is re-emphasized. 6. 6. The anatomic differences between sphincteroplasty and sphincterotomy are described. 7. 7. The physiologic differences between these operations are demonstrable by postoperative T tube pressure studies, postoperative T tube cholangiograms, postoperative cineradiography, postoperative upper gastrointestinal studies, and clinical results. 8. 8. Indications and contraindications for sphincteroplasty are outlined. 9. 9. Two hundred forty-one sphincteroplasties are reported with an over-all mortality of 1.24 per cent and a morbidity of 4.9 per cent. 10. 10. Of the ninety-five patients with recurrent pancreatitis and no intrapancreatic ductal obstruction , 90.5 per cent were improved or asymptomatic after sphincteroplasty. This optimistic figure is misleading since forty-four of the ninety-five patients had calculous biliary tract disease, and a substantial number might have been relieved by eradication of this alone. However, in fifty patients with recurrent pancreatitis, no calculous disease, and no intrapancreatic ductal obstruction, the benefits derived appear to be due to the sphincteroplasty. 11. 11. All of the 146 patients with extrahepatic biliary tract obstruction were relieved of symptoms by sphincteroplasty. One hundred thirty-nine of these were operated upon for multiple common duct stones. No recurrent or residual stones developed after sphincteroplasty. 12. 12. Although sphincteroplasty should be performed only by a surgeon familiar with biliary tract surgery, we believe that if the technic outlined is carefully followed, the operation may be accomplished with minimal morbidity and mortality.

Arteriomesenteric duodenal compression

Abstract 1. 1. Fourteen surgically treated patients with arteriomesenteric duodenal compression are presented. Twelve have been relieved of digestive symptoms, and two are improved. 2. 2. A high index of suspicion is advocated in evaluating patients with vague abdominal complaints of long-standing. 3. 3. Methods of diagnosing this condition at the operating table are discussed. In four cases, five abdominal operations by other surgeons had failed to demonstrate the condition. Air insufflation has been of value in our hands in recognizing this syndrome. 4. 4. Diagnosis by roentgenogram is not certain. The condition may be overlooked or diagnosed too frequently. 5. 5. This syndrome should be considered when surgery for peptic ulcers is indicated. The presence of arteriomesenteric duodenal compression will alter the surgical procedure used in the treatment of patients with ulcers. Patients who have had a poor response to surgery for ulcers should be re-evaluated with this condition in mind. 6. 6. This clinical entity should be treated surgically if medical treatment fails. Conservatism in both diagnosis and treatment must be stressed. 7. 7. The accuracy of the conclusions drawn in this preliminary paper must be determined by further studies.

SURGICAL MANAGEMENT OF THE DIFFICULT AND PERFORATED DUODENAL STUMP: AN EXPERIMENTAL STUDY.

Abstract 1. 1. Neither current operative technics nor primary duodenal drainage completely answers the problem of the difficult duodenal stump. 2. 2. The perforated duodenal stump remains a major cause of mortality following gastric resection. 3. 3. Primary closure of the dogs duodenal stump using intact jejunal wall was uniformly successful in this study. 4. 4. The use of intact jejunal wall to seal the leaking duodenal stump was similarly effective. 5. 5. Unoperated duodenal perforation was lethal in a high percentage of our control animals. 6. 6. These observations suggest that this principle of closure may be of value in treating (1) the occasional difficult duodenal stump and (2) the perforated duodenal stump.

Circulatory effects of acute lactic acidosis in dogs prior to and after hemorrhage

Abstract The hemodynamic effects of acute lactic acidosis have been studied in dogs whose pO 2 and pCO 2 have been maintained within normal limits prior to and after a standard hemorrhagic challenge. Lactic acidosis in this study seriously impaired cardiac function as evidenced by a slight fall in arterial pressure, a rise in central venous pressure, and a marked decrease in cardiac output. Total peripheral resistance showed a significant rise. Electrocardiograms demonstrated sinus bradycardia, sinus pauses, and temporary sinus arrest as well as peaking of the T wave. Hemorrhage in these animals with acidosis did not initiate cardiovascular decompensation. They responded by an additional rise in peripheral resistance despite a further fall in arterial pressure and cardiac output, indicating an intact and functional peripheral vasculature. It was concluded from these findings that the effect of lactic acidosis is primarily on the heart and not on the peripheral vessels. Although lactic acidemia is not a causative factor in the production of shock, its effect on the heart may become a serious aggravating feature of the shock state. Its presence should be suspected in patients showing a refractory response to specific shock therapy and attention should be directed toward its prompt correction by alkalinizing agents or buffer solutions.

Continuous blood pH monitoring using an indwelling catheter

1. 1. A pH microelectrode mounted on the tip of a cardiac catheter is described which enables continuous pH monitoring. 2. 2. Experimental studies in dogs demonstrate the accuracy of this in vivo pH electrode when compared to the value measured anaerobically by a conventional bench pH meter. 3. 3. Clinical observations indicate that the indwelling microelectrode is stable for at least seven hours and shows a rapid response to changes occurring during surgical procedures. 4. 4. Constant blood pH surveillance is of value in the management of low perfusion states as well as during complicated cardiovascular procedures.

Acute arterial injuries of the upper extremity

Abstract Prompt recognition and immediate surgical repair is recommended in the management of acute arterial injuries to the upper extremity. This therapeutic concept is most urgent in injuries involving the larger proximal vessels where hemorrhage frequently threatens survival. Well established incisions and current vascular surgical technics preclude equivocation in the management of injuries in this location. Damage to peripheral arteries of the arm and forearm should also be repaired immediately in order to restore optimal circulation unless such emergency repair jeopardizes survival of the patient. Ligation can be performed in injuries in this location with minimal risk of amputation. Arteriography is helpful in establishing the diagnosis of arterial injury in equivocal cases and will reduce the number of negative explorations. Careful attention must be paid to the total problem of trauma in patients with acute arterial injury of the upper extremity since associated damage to nerves and tendons is the determining factor in restoration of function and rehabilitation of the patient.

Blood gas and carotid pressure: factors in stroke risk.

The internal carotid back pressure and arterial blood gas measurements have been employed in 269 patients undergoing 332 carotid endarterectomies in an effort to identify individuals at high risk of stroke during surgery. Patients having an internal carotid back pressure less than 25 Torr were operated using an inlying shunt. There were 159 patients having a Paco2, greater than 45 Torr, 95 individuals with a Paco2 between 35 to 45 Torr and 78 cases with a Paco2 less than 35 Torr. The mean internal carotid back pressure was 63 Torr in the hypo-carbic group and 45 Torr in the hypercarbic patients which represents a highly significant inverse relationship between Paco2 and carotid back pressure (P < 0.0002). There were four neurological deficits following surgery in the hypercarbic group and one each in the normocarbic and hypocarbic groups. These findings suggest a lower stroke incidence in patients having hypocarbic or normocarbic general anesthesia than those receiving hypercarbic general anesthesia. The low overall stroke rate of 2% indicates the safety of selective shunting during carotid endarterectomy.

Prevention and treatment of acute renal failure: An experimental study

Abstract 1. 1. Experimental renal failure has been produced in seventy-six dogs by a combination of operation (right nephrectomy), ischemia, and the administration of acid hematin solution. Mannitol, low molecular weight dextran, THAM, and 5 per cent dextrose in water have been compared regarding their relative effectiveness in preventing or prolonging survival after the induction of renal failure. 2. 2. Mannitol, low molecular weight dextran, and the organic buffer THAM, in the experimental setting of this study, did not appear to be more beneficial than 5 per cent dextrose in water in preventing or prolonging survival after the induction of acute renal failure. Extensive petechial hemorrhages involving the mesentery and serosa of the bowel were frequently observed in animals receiving low molecular weight dextran. 3. 3. Control groups (animals receiving 5 per cent dextrose in water solution) consistently had the most seven day survivors as well as the longest mean survival times of any of the groups studied. 4. 4. The beneficial effect of adequate hydration prior to the performance of diagnostic procedures or operations known to be associated with renal damage is emphasized.

Atropine, norepinephrine, and isoproterenol and the cardiac response to experimental lactic acidosis

Abstract Acute addition lactic acidosis causes marked cardiac slowing, decreased cardiac output, and a progressive rise in the central venous pressure in the dog, suggesting increased vagal activity as well as decreased myocardial function. Bilateral cervical vagotomy and atropine in large dosages were employed to evaluate the role of vagal innervation in producing bradycardia and rhythm changes during acute lactic acidosis. These experimental procedures increased cardiac rate but did not improve cardiac output after the induction of lactic acidosis. Isoproterenol was compared with norepinephrine as a therapeutic agent to improve myocardial function during acidosis. Norepinephrine administration increased arterial pressure by 16 per cent, but did not improve cardiac output or cardiac rate when infused during acidosis. By contrast, isoproterenol caused a 10 per cent fall in arterial pressure, a 93.5 per cent increase in the cardiac output, and a 32 per cent increase in cardiac rate. These experimental findings suggest that increased vagal activity is a cause for the bradycardia and rhythm changes observed during acute lactic acidosis. Isoproterenol was an effective therapeutic agent to improve cardiac output, decrease peripheral resistance, and increase cardiac rate during severe acidosis. The application of these findings to the management of low perfusion states has been discussed.