James H. McClenathan

Significance of subendocardial S-T segment elevation caused by coronary stenosis in the dog

A model of partial thickness ischemia has been developed using subendocardial S-T elevation without epicardial S-T elevation to detect partial thickness ischemia which is sufficient to cause subsequent necrosis. Subendocardial blood flow in this model (measured with radioactive microsphere techniques) may be reduced to 25 percent of normal (P less than 0.001) by coronary stenosis and tachycardia while subepicardial flow remains normal. Epicardial S-T depression seems to indicate reciprocally subendocardial S-T elevation as long as a layer of nonischemic epicardial muscle is present, but when ischemia becomes transmural, epicardial S-T elevation occurs. Regional pressure-flow relations were determined as distal coronary pressure was reduced at a constant aortic pressure, heart rate and cardiac output. These relations revealed remarkably effective autoregulation of epicardial blood flow concomitant with progressive subendocardial ischemia.

Adenoid cystic breast cancer

BACKGROUND Adenoid cystic carcinoma is a rare type of breast cancer that is generally reported in individual case reports or as series from major referral centers. To characterize early diagnostic criteria for adenoid cystic carcinoma and to determine whether breast-preserving surgery with radiotherapy is as effective as mastectomy for eradicating the disease, we reviewed clinical records of a large series of patients treated for adenoid cystic carcinoma of the breast at a large health maintenance organization (HMO) that includes primary care facilities and referral centers. METHODS Using the data bank of the Northern California Cancer Registry of the Kaiser Permanente Northern California Region (KPNCR), we retrospectively reviewed medical records of patients treated for adenoid cystic carcinoma of the breast. Follow-up also was done for these patients. RESULTS Adenoid cystic carcinoma of the breast was diagnosed in 22 of 27,970 patients treated for breast cancer at KPNCR from 1960 through 2000. All 22 patients were female and were available for follow-up. Mean age of patients at diagnosis was 61 years (range, 37 to 94 years). In 17 (77%) of the women, a lump in the breast led to initial suspicion of a tumor; in 4 (23%) of the 22 patients, mammography led to suspicion of a tumor. Median tumor size was 20 mm. Pain was a prominent symptom. Surgical management evolved from radical and modified radical mastectomy to simple mastectomy or lumpectomy during the study period, during which time 1 patient died of previous ordinary ductal carcinoma of the contralateral breast, and 7 died of unrelated disease. At follow-up, 12 of the 13 remaining patients were free of disease; 1 patient died of the disease; and 1 patient remained alive despite late occurrence of lymph node and pulmonary metastases. CONCLUSIONS Whether breast-preserving surgery with radiotherapy is as effective as mastectomy for treating adenoid cystic carcinoma of the breast has not been determined.

Ductal carcinoma in situ of the breast: Results of treatment by conservative surgery and definitive irradiation

PURPOSE To determine local control, survivorship, and cosmesis in women with ductal carcinoma in situ treated by conservative surgery and radiation therapy. METHODS AND MATERIALS We retrospectively analyzed the results of treatment in 56 women with in situ carcinoma of the breast, treated between 1976 and 1990 by conservative surgery and irradiation. Two women had bilateral tumors, for a total of 58 breasts at risk. All patients underwent gross excision of the tumor followed by radiation to the entire breast and a sequential boost to the tumor bed. Eight of the 21 evaluable tumors (38%) had inadequate pathologic margins at the time of excision. Routine re-excision was not performed. The median dose to the whole breast and primary tumor site was 5000 cGy and 6940 cGy, respectively. Median follow-up was 61 months (range 27-191 months). RESULTS Five patients (9%) failed in the breast for an 8-year actuarial local failure rate of 11%. Median time to failure was 34 months. All five patients with local recurrence underwent mastectomy and are alive, without evidence of disease at a mean of 40 months post mastectomy. The 8-year actuarial absolute and cause specific survivals were 89% and 100%, respectively. Cosmetic results were excellent or totally acceptable in 90% of patients. CONCLUSION Patients with ductal carcinoma in situ treated by excision and irradiation achieved acceptable local control and excellent survival and cosmetic results. Because of the long time course associated with local failure, diligent and protracted follow-up is mandatory.

Evolution of regional ischemia distal to a proximal coronary stenosis: Self-propagation of ischemia

The temporal evolution of myocardial ischemia was studied in open chest dogs at constant preload, afterload and heart rate. In one group of animals, a variable circumflex arterial stenosis was used to maintain constant distal circumflex arterial hypotension (40 to 50 mm Hg). During a 3 hour period of stenosis, flow in the subendocardial fourth of the ischemic ventricular wall decreased from 0.22 to 0.09 ml/g per min (P less than 0.02), whereas subepicardial flow was not significantly changed. Local vascular resistance, therefore, doubled in the most ischemic area of myocardium. In a second group of animals in which proximal coronary stenosis was held constant and pressure varied, an ischemia-mediated increase in local vascular resistance was also demonstrated. In addition, a reciprocal relation was observed between changes in flow in the left anterior descending coronary region and changes in collateral flow to the region of the circumflex artery. A coronary steal mechanism and an ischemia-mediated resistance increase may be two means by which ischemia is self-propagating.

Clinical presentation of mucin-secreting tumors of the pancreas

BACKGROUND Pancreatitis and jaundice secondary to ductal obstruction are common in intraductal papillary mucinous tumors (IPMT) of the pancreas. However, the incidence and severity of the complications of obstruction are not well documented. The aim of the study was to investigate the clinical presentation and outcome of 10 patients with IPMT. METHODS All cases of IPMT diagnosed between 1994 and 1999 were reviewed. RESULTS Four of the 10 patients developed severe acute illness with systemic complications resulting from ductal obstruction. Three suffered acute cholangitis with sepsis, and 1 developed necrotizing pancreatitis and ARDS. There was 1 postoperative death in a patient with adenocarcinoma. All other patients are alive and well with a median follow-up of 26 months (survival 90%). CONCLUSIONS Pancreatic or common bile duct obstruction in IPMT may result in acute, life-threatening disease. Aggressive surgical therapy is warranted before development of complications of ductal obstruction or progression of tumor occurs.

Metastatic melanoma involving the colon

A patient with isolated cecal metastasis of malignant melanoma whose symptoms of fatigue, exertional dyspnea, and an abdominal mass were relieved by operation is reported. Palliative resection appears to offer significant benefit in patients with symptomatic melanoma involving the colon, particularly if the lesion is solitary

Primary neurilemoma of the diaphragm

A neurilemoma of the diaphragm in an asymptomatic 46-year-old woman is reported, and 12 cases of primary neural tumor of the diaphragm reported previously are reviewed. The common symptoms in these patients are chest pain, cough, and dyspnea. Joint pain or clubbing of the fingers is present in nearly half of the patients. As with diaphragmatic tumors in general, many neural tumors of the diaphragm are malignant. We believe that all such tumors should be resected through a thoracotomy incision, which affords optimal exposure of the diaphragm.

A Mechanical Device for Sutureless Aorta—Saphenous Vein Anastomosis

The aorta-saphenous vein anastomosis is a very common anastomosis with constant anatomy. A device for sutureless aortovenous anastomosis is presented which adapts the principle of venous eversion to the end-to-side anastomosis. The use of this device in 20 dogs demonstrated that reasonable early patency (85%) and subsequent long-term patency (100%) can be achieved. The device possesses the potential for rapid multiple anastomoses to the proximal aorta, but the eversion principle requires that the anastomosis be smaller than the vein utilized. Clinical application of this technique will require both modification to enlarge the anastomosis and demonstration of long-term patency competitive with suture techniques. The device is not yet ready for clinical use.

Abdominal Pain Caused by Thrombosis of a Gastroepiploic Artery Aneurysm: A Case Report

Symptomatic visceral aneurysms usually present with abdominal pain and shock, gastrointestinal bleeding, or hemobilia when the aneurysm ruptures. Less frequently, visceral aneurysms are found incidentally during abdominal computed tomography or angiography. Thrombosis is a frequent complication of popliteal and femoral aneurysms but is rarely seen with a visceral aneurysm. The author believes this is the first report of complete thrombosis of a gastroepiploic artery aneurysm. The patient, who was seen for abdominal pain, had a previously unrecognized aneurysm.

The effects of arterial CO2 tension on regional myocardial and renal blood flow: An experimental study

Abstract Radioactive microspheres were used to determine the effects of hypercapnia and hypocapnia on regional myocardial and renal blood flow and cardiovascular hemodynamics in an animal model in which arterial pH and p O 2 were maintained at constant levels. An increase in arterial p CO 2 effected an increase in both transmural coronary and intrarenal blood flow which was due to a reduction in coronary and renal vascular resistance. A marked reduction in arterial p CO 2 , however, did not influence coronary and renal flow or resistance. When compared to the hypocapnic state, hypercapnia and the resultant increase in coronary blood flow provided a modest improvement in ventricular work at the same level of myocardial contractility.