John A. Belis

COMPLETE RADICAL NEPHRECTOMY AND VENA CAVAL THROMBECTOMY DURING CIRCULATORY ARREST

PURPOSE A modification of radical nephrectomy for renal carcinoma and vena caval tumor thrombectomy for supradiaphragmatic tumor extension under hypothermic circulatory arrest is presented. MATERIALS AND METHODS Nephrectomy was performed during the circulatory arrest time in 16 consecutive patients during the last 4 years. RESULTS Average hypothermic circulatory arrest time increased by 6 minutes. By elimination of manipulation of tumor and thrombus before circulatory arrest potential thrombus fragmentation and embolization were minimized. There were no significant differences in blood loss or complications compared to a prior series of 10 patients undergoing the procedure using conventional techniques. CONCLUSIONS Performance of complete radical nephrectomy along with venal caval embolectomy during circulatory arrest increases the safety of the procedure without significant morbidity.

Cardiovascular evaluation before circulatory arrest for removal of vena caval extension of renal carcinoma.

The use of cardiopulmonary bypass, deep hypothermia and circulatory arrest has decreased the risks of hemorrhage, tumor embolization, incomplete thrombus resection, and warm hepatic and renal ischemia associated with resection of renal cell carcinoma extending into the inferior vena cava above the hepatic veins. Patients about to undergo this operation frequently have significant coronary artery and carotid artery disease, and are at risk for perioperative myocardial infarction and stroke. Preoperative evaluation of the coronary artery and carotid artery circulation by coronary angiography, duplex carotid artery scan and digital subtraction carotid angiography is recommended. Depending upon the severity and location of the cardiovascular disease a sequential or simultaneous operation may be performed. This surgical approach can be used in selected patients to facilitate complete tumor thrombectomy with a low operative risk.

Atypical renal adenocarcinoma with features suggesting collecting duct origin and mimicking a mucinous adenocarcinoma

We report a case of an atypical renal adenocarcinoma of the renal medulla associated with a marked desmoplastic response and interstitial mucin production. Collecting duct epithelium of the renal medulla throughout the kidney showed cytologic atypia. These features have been described by others as suggestive of a collecting duct histogenesis. This case represents the fifteenth reported case known to us of a renal adenocarcinoma of collecting duct origin. Prior reports, however, have not described the extensive mucin production that may be associated.

Calcium Channel Agonist/Antagonist Effects on Cholinergic Stimulation of the Diabetic Rat Bladder

The in vitro effects of a calcium channel agonist (BAY K8644) and antagonist (nifedipine) on the cholinergic responses of the streptozotocin-induced diabetic rat bladder were investigated. the bladder body and bladder base were studied separately. There were significant differences in contractile responses to acetylcholine stimulation in the diabetic bladder body compared to the control body. Similarly, the diabetic bladder base demonstrated significantly increased contractile responses compared to the control base. Contractile responses in the diabetic bladder body and base were significantly increased from the control in the absence of extracellular calcium. Differences were found in the effects on maximum responses between diabetic and control tissues treated with nifedipine and BAY K8644. BAY K8644 did not completely reverse the effect of nifedipine on the contractile responses. Rates of contractile response were significantly different between controls and diabetics and between body and base. Alterations in calcium channel activity in diabetic bladder smooth muscle may be responsible at least in part for the nonspecific pharmacologic responses found in smooth muscle strips.

Bladder Dysfunction in the Spontaneously Diabetic Male Abyssinian-Hartley Guinea Pig

The spontaneously diabetic adult male Abyssinian-Hartley guinea pig develops bladder hypertrophy and voiding dysfunction. In contrast to animals with chemically induced diabetes, this animal demonstrates changes in bladder function in the absence of diuresis. The diabetic guinea pigs void a total daily volume similar to that of control animals, but have a greater mean volume per void and a longer interval between voiding. Cystometry demonstrates that the diabetic guinea pig produces greater intraluminal bladder pressure, but maintains voiding pressure for a shorter interval. A significantly decreased contractile response of the diabetic bladder base may be responsible for the bladder hypertrophy and voiding dysfunction.

Cytosol-Free Calcium Concentration in Single Bladder Smooth Muscle Cells from Normal and Diabetic Rats

The effect of diabetes mellitus on intracellular calcium concentration was measured in single rat bladder smooth muscle cells using the fluorescent calcium indicator dye fura-2 AM. Techniques were developed for isolation and short-term culture of rat bladder smooth muscle cells. Cytosol-free calcium concentrations were measured at rest and during carbachol stimulation. Peak intracellular calcium concentration, rate of increase in intracellular calcium concentration and the integral of accumulation of intracellular calcium were determined. The techniques used to isolate and culture bladder smooth muscle cells produced live, physiologically responsive cells. Resting intracellular free calcium levels and were similar in control and diabetic cells. Both control and diabetic cells responded to carbachol stimulation. No significant differences between these cells were noted in peak calcium concentrations, rate of response or integral of response, but standard errors were large. Two patterns of intracellular response to carbachol stimulation were identified, and may explain the large variability in intracellular calcium response to carbachol stimulation.

Neurogenic Function of the Diabetic Rat Bladder: Alteration by Calcium Channel Effectors

The in vitro effects of a calcium channel antagonist (nifedipine) and agonist (BAY K8644) on the neurogenic responses of the streptozotocin-induced diabetic rat bladder were investigated. The bladder body and bladder base were studied separately. There were no significant differences in neurogenic responses in diabetic bladder body compared to control body, but the diabetic bladder base demonstrated an increased contractile response at each frequency compared to control base. The rate of contractile response was similar in controls and diabetics but was significantly different between body and base. Although declining with time, contractile responses in the diabetic bladder body and base were increased from control in the absence of extracellular calcium. Differences were found in effects upon maximum responses between diabetic and control tissues treated with nifedipine and BAY K8644. BAY K8644 did not completely reverse the effect of nifedipine on the neurogenic responses in the diabetic bladder body. Effects of diabetes on the bladder body and base are associated with changes in calcium channel activity of bladder smooth muscle.

Desmopressin Control of Surgical Hemorrhage Secondary to Prolonged Bleeding Time

Desmopressin has been used as a hemostatic agent in numerous hematological and nonhematological diseases. We report a case of surgical hemorrhage secondary to prolonged bleeding time of unexplained origin controlled with desmopressin.

Combined Carotid Endarterectomy, Coronary Revascularization, and Hypernephroma Excision with Hypothermic Circulatory Arrest

Approximately 5% of renal cell carcinomas invade the inferior vena cava (IVC), forming friable, pedunculated tumor thrombus that can embolize. Fourteen to 16% of these tumor thrombi extend as far as the right atrium, in which case tricuspid valve obstruction can present an immediate threat to life (1-3). To reduce the risk of embolization during surgical manipulation and to allow complete tumor resection, the use of cardiopulmonary bypass (CPB) has been reported in patients with renal tumors (P8). However, isolation of the affected portion of the vena cava and control of intraoperative bleeding may be difficult with conventional CPB. Therefore, CPB with total circulatory arrest has been used to provide adequate operating conditions for excision of renal tumors (9-1 1). To our knowledge, however, this is the first report of the use of hypothermic circulatory arrest in a patient undergoing combined renal cell carcinoma excision, coronary revascularization, and carotid endarterectomy. The combination of these three procedures exposed this patient to cerebral ischemia, for which we used a multifaceted approach to provide cerebral protection.

Comparison of computerized cystometry/micturition and contractile responses of the diabetic rat bladder.

Computerized data acquisition was used to achieve a comprehensive assessment of micturition and cystometry in rats made diabetic with streptozotocin. Diabetic rats had a greater mean voided volume and a significantly shorter interval between voiding during the light cycle. During volume expulsion, the rate of intraluminal pressure development was greater, but the mean duration of volume expulsion was less in the diabetic bladder. The increased rate of intraluminal pressure development in the diabetic bladder at the time of volume expulsion correlated with the greater tension development in bladder body strips in response to acetylcholine stimulation. The inability of the diabetic bladder body to maintain peak intraluminal pressure may contribute to the development of residual urine, increased bladder volume and increased voiding frequency in the diabetic rat.