Acute gastric volvulus: pathogenesis, diagnosis, and treatment.

A 61-yr-old women presented with vomiting, abdominal pain, and distention. Nasogastric and endoscopic decompression failed to relieve her distention. Radiographic studies suggested gastric necrosis without other pathology. Laparotomy revealed a rare form of mesenteroaxial volvulus of the fundus with frank necrosis. The patient underwent gastric resection with anterior gastropexy followed by an uncomplicated postoperative course. This paper discusses the etiology, anatomic definition, and therapeutic options in patients with acute gastric volvulus.

Intraoperative thrombolysis in peripheral arterial occlusion.

Thromboembolic occlusion of peripheral arteries continues to be associated with significant morbidity, mortality and loss of limbs. Surgical intervention with prompt revascularization by clot extraction, alone or in combination with arterial bypass, remains the standard therapy for critical ischemia with imminent tissue loss. Mechanical thrombectomy using a balloon catheter has been the preferred technique for distal embolus or thrombus extraction. Unfortunately, complete thrombectomy is rare, and the procedure is associated with arterial wall injury. Intraoperative thrombolytic therapy is an attractive adjunct to catheter thrombectomy alone and is appropriate in the care of a significant number of patients with acute limb ischemia. Its safety and efficacy have been confirmed in the laboratory and in a limited number of patients. The authors review experimental and clinical data and report their experience with 19 patients.

Laparoscopy through an inguinal hernia for diagnosis of intraperitoneal pathology.

During the repair of an incarcerated inguinal hernia, a 68-year-old gentleman was found to have unsuspected ascites. Upon palpation of the peritoneal cavity through the hernial sac, superficial nodules could be appreciated, suggesting abnormal pathology. A laparoscope was placed through the hernia sac after establishing a pneumoperitoneum through the same approach. This allowed visualization of the entire peritoneal cavity and appropriate exploration of the abdominal viscera. Biopsies confirmed unsuspected metastatic renal cell carcinoma. The authors describe this technique and suggest possible indications for its use.

Intestinal herpes simplex infection presenting with intestinal perforation.

A 77-yr-old man who had received systemic steroids for more than 6 yr presented with an acute abdomen. Laparotomy revealed an ulcerative jejunitis with purulent peritonitis. The patient underwent resection of involved bowel followed by a 10-day course of aciclovir, with excellent results. Pathologic examination showed a necrotizing enteritis with intranuclear inclusions typical of Herpesvirus that reacted immunocytochemically with antibodies to herpes simplex virus types I and II. A rising herpes simplex virus serum antibody titer confirmed the diagnosis. Intestinal herpes infection with perforation should be added to the list of complications from herpes simplex in the immunocompromised patient.

A magnetically actuated left ventricular assist device.

Over the past 6 years, research has led to development of a small, lightweight, power-efficient, uniquely simple ventricular assist device driven by a magnetic actuator. Magnetic actuation permits total elimination of all mechanical motion converter components used for pusher plate displacement, resulting in a significant reduction in complexity and resultant increase in reliability. Extensive in vitro mock loop development has resulted in a left ventricular assist device (LVAD), the primary design parameters of which for the clinical prototype actuator and pump are 1) an actuator weight of 312 g, 2) actuator size of 32.5 cm3, 3) power requirements of 7.8 to 11.4 watts (60-100 beats per minute [BPM]), and 4) system efficiency of 24% to 34% and average dynamic stroke volume of 65 ml. Initial in vivo tests assessed this LVAD's performance in four sheep under three acute conditions of ventricular dysfunction. The results demonstrate that, at a pump-rate of 100 BPM, mean aortic pressure increased by 45-50 mmHg during 1) beta blockade, 2) coronary ligation, and 3) ventricular fibrillation. Pump flow ranged from 2.71 L/min to a maximum of 4.6 L/min. Acute test periods were arbitrarily set for 6 hours duration. Of the four sheep, two survived, one lived 5 hours, and the fourth lived 4.5 hours. Global fibrillation was the primary cause of failure. This initial in vivo data demonstrates the pump's ability to maintain satisfactory hemodynamic parameters of flow and pressure under three acute conditions of extreme left ventricular dysfunction in an animal model. These initial LVAD performances were encouraging. Further tests will use calves with a greatly expanded performance evaluation protocol.

Detection of occult lymph node metastases in malignant melanoma.

An accurate prediction of the prognosis of melanoma is dependent on the ability to determine the presence or absence of malignant cells in lymph nodes. Our laboratory has developed a method for screening lymph node sections for the presence of micrometastatic disease. The nodes obtained from regional lymphadenectomies are dissected free from surrounding tissue and divided into halves. One-half is subjected to routine histopathological evaluation and the other one-half is disrupted into a single cell suspension and placed into cell culture. Lymph nodes from 19 patients with malignant melanoma were evaluated by tissue culture. Tumor cells were isolated in 125 of the 173 nodes examined. In contrast, only 14 of these nodes were initially found positive for melanoma by routine pathological evaluation. All lymph nodes positive for melanoma by pathological evaluation were also culture positive. Examination by cell culture has led to an upgrade in the stage of disease in 58% of the histologically node-negative patients. In addition, 43% of the patients who were histologically node negative but culture positive have recurred, suggesting some clinical correlation. These results indicate that the tissue culture method for detecting micrometastatic lymph node disease may prove more reliable and sensitive than current techniques for determining the presence of occult melanoma.

Detection of submicroscopic lymph node metastases in patients with melanoma.

A cell culture technique was developed to investigate submicroscopic lymph node metastases in patients with stage 1 or 2 malignant melanoma. Lymph nodes were isolated from standard dissections and bivalved. Half of the node was evaluated by routine histopathologic examination, while the other half was processed and placed into tissue culture. Three hundred twenty-three lymph nodes were collected from 41 patients. The cell culture technique identified 155 of 323 lymph nodes containing micrometastases, while only 20 of 323 lymph nodes tested positive with routine histochemical processing. Nine patients were upgraded from stage 1 or 2 to stage 3 disease after micrometastases were identified in lymph node cultures. Identification of melanoma was confirmed by cytologic examination, immunohistologic staining, and the presence of GD3 ganglioside and 250-kd glycoprotein melanoma-associated antigens. This study provides evidence that the culture of lymph nodes is a sensitive method for the detection of micrometastases. In addition, this procedure may change prognosis and identify candidates for adjuvant therapies.

Localization of malignant melanoma using monoclonal antibodies.

Finding a screening test to evaluate patients with cancer for occult metastatic disease, as well as imaging all known disease, is a goal of research efforts. Twenty-nine evaluable patients with deeply invasive (stage I), regional nodal (stage II), or systemic (stage III) melanoma underwent imaging by administration of a preparation of the antimelanoma antibody labeled with technetium 99m. Scan results indicated that 28 of 32 confirmed metastatic sites were imaged with this technique (88% sensitivity). Analysis of the individual positive sites revealed that nodal basins and visceral metastases accounted for the highest percentage of metastatic sites imaged, with 14 (88%) of 16 nodal basin metastases and all four visceral metastases being detected through imaging. Occult nodal disease was detected in the iliac nodal chain in two of the 29 patients. The imaging of benign tumors and nodal basins not containing disease accounted for a confirmed false-positive rate of 21%. Three (10%) of the 29 scan results were confirmed to be false-negative. In vivo tumor localization with monoclonal antibodies showed a sensitivity similar to that of other roentgenographic procedures for identifying metastatic disease and was useful in two of three patients in identifying occult iliac nodal disease, a region that is difficult to evaluate with physical examination and other imaging modalities.

A comparison of choledochoenteric bypass and cholecystoenteric bypass in patients with biliary obstruction due to pancreatic cancer.

Debate concerning the superiority of cholecystoenteric bypass (CCEB) vs. choledochoenteric bypass (CDEB) in patients with pancreatic cancer and biliary obstruction prompted this review. Thirty-six patients with biliary duct obstruction due to pancreatic cancer underwent 37 operations for biliary decompression between 1976 and 1986: 22 CCEB, 15 CDEB. Age, sex, race, preoperative health, and preoperative symptoms and signs were similar for both groups. Seven CDEB patients had previous cholecystectomy (n = 5) and failed CCEB (n = 2). Twenty CCEB patients and 13 CDEB patients had elevated preoperative total bilirubin with an average abnormal bilirubin of 15.3 mg per cent and 12.0 mg per cent, respectively. Perioperative significant morbidity/mortality was seen in 59.1 per cent and 22.7 per cent, respectively, in CCEB and 53.3 per cent and 6.7 per cent in CDEB. Twenty (90.9%) CCEB patients and 15 (100%) CDEB eventually succumbed to either their operation or pancreatic cancer: average survival was 7.5 months (range, 2-41 months) and 10.4 months (range, 2-30 months), respectively. Two CCEB patients were alive at 15 and 41 months. Eleven out of 22 CCEB patients (50%) experienced short term (within 2 months of surgery) absence of jaundice, icterus, pruritus, and biliary tract disease symptoms or signs, and six out of 12 experienced long term (more than 3 months after surgery) absence of these problems; with CDEB, 14 patients out of 15 (93%) experienced short term and 10 out of 12 patients (83%) experienced long term absence of these problems. Cholecystoenteric bypass is a significantly morbid procedure and yet does not reliably palliate biliary obstruction due to pancreatic cancer; it is not preferred.