Venodilator effects of adenosine triphosphate and sodium nitroprusside; Comparisons during controlled hypotension

Adenosine triphosphate as well as sodium nitroprusside has been used for hypotensive anesthesia. The purpose of this study was to examine the possibility that two hypotensive drugs may exert different effects on venous capacitance during controlled hypotension. In rats anesthetized with ketamine, mean arterial pressure was lowered to 50mmHg by intravenous infusion of adenosine triphosphate or sodium nitroprusside. Venous capacitance was assessed before and during induced hypotension by measuring the mean circulatory filling pressure (MCFP). MCFP was measured after briefly arresting the circulation by inflating an indwelling balloon in the right atrium. MCFP was lower during adenosine triphosphate-induced as well as sodium nitroprusside-induced hypotension as compared with the respective value at control (P < 0.01 for adenosine triphosphate and sodium nitroprusside). However, the decrease in MCFP by adenosine triphosphate (0.8 ± 0.1mmHg) was less (P < 0.01) than that by sodium nitroprusside (2.3 ± 0.3mmHg). These results suggest that at a comparable level of arterial hypotension venodilator effect of adenosine triphosphate was less than that of sodium nitroprusside. Less venodilatation during adenosine triphosphate-induced hypotension may contribute to the maintenance of cardiac output during hypotensive anesthesia.(Hoka S, Takeshita A, Aishima K et al.: Venodilator effects of adenosine triphosphate and sodium nitroprusside; comparisons during controlled hypotension. J Anesth 1: 144–147, 1987)     

Surgery of basilar aneurysms associated with unexpected rupture of an internal carotid artery aneurysm

During a surgery of basilar aneurysms via the trans-sylvian approach, we encountered an arterial bleeding caused by rupture of an internal carotid artery aneurysm that had been difficult to diagnose before surgery, as it was a small and brood-neck aneurysm and mimicked arteriosclerosis. In spite of several surgical procedures, the surgical path at the basilar aneurysms became narrow, and we had to abandon the clipping of the aneurysms. Consideration of radiological and intraoperative findings was made for this case, demonstrating a pitfall that neurosurgeons may encounter during surgery. Received: 16 December 1998 / Accepted: 26 May 1999     

Infantile hemangioendothelioma of the thymus with massive pleural effusion and Kasabach-Merritt syndrome: Histopathological, flow cytometrical analysis of the tumor

Infantile hemangioendothelioma of the thymus is a rare disease. We describe a patient who developed a large anterior mediastinal mass, severe thrombocytopenia and massive pleural effusion at 1 month of age. Glucocorticosteroid and irradiation therapy had no effect on either the tumor size or clinical symptoms and the tumor was resected subtotally. Three months after the subtotal resection, the remaining tumor had almost disappeared and the symptoms had resolved. The patient has now been well for 1 year after surgery without evidence of recurrence. The tumor tissue was characterized by prominent vascular endothelial proliferation intermixed with a normal thymic structure, producing a picture consistent with that of an infantile hemangioendothelioma in the thymus, lmmunohistochemically, the tumor cells showed positive staining for vimentin, factor VIII and CD34. The DNA stemline and proliferative activity were examined by flow cytometry, which revealed a diploid stemline with a low growth fraction. DNA content and cell cycle analyses of the tumor tissue may be useful for predicting the biological behavior of the tumor.     

A case of primary gastric small cell carcinoma with a rare pattern of lymph node metastasis

We report a very rare case of primary gastric small cell carcinoma (GSCC) that was accompanied with gastric tubular adenocarcinoma. A male in his 60s had an elevated tumor with a central ulceration in the middle stomach. The patient underwent a distal gastrectomy with lymph node dissection. The pathological examination showed two separated lesions of the stomach, which contained the components of primary GSCC and primary gastric tubular adenocarcinoma. Immunohistochemical (IHC) examination demonstrated that the tumor cells in the small cell carcinoma stained positive for synaptophysin, chromogranin A, and neural cell adhesion molecule (NCAM). GSCC cells and adenocarcinoma cells independently metastasized to each regional lymph node. Further studies on the biological behavior of individual tumors may allow the development of new treatment strategies for GSCC.     

Intraperitoneal exfoliated cancer cells in patients with colorectal cancer

PURPOSE: The aims of this study were to evaluate potential predictors of exfoliated free cancer cells in the peritoneal cavity and to assess intraoperative peritoneal lavage cytology as a prognostic indicator in patients with colorectal cancer. METHODS: From 1985 to 1987, intraoperative peritoneal lavage cytology was performed in 140 patients with colorectal cancer. Among them, 88 patients underwent curative resection and 52 patients had noncurative surgery. Cytology was examined twice,i.e., immediately after opening the peritoneal cavity (precytology) and just before closing the abdomen (postcytology). One hundred milliliters of saline was poured into the peritoneal cavity and it was retrieved by suction after irrigation. Cytologic examination was performed after staining with Papanicolaou, Giemsa, periodic acid-Schiff, and Alcian blue stains. RESULTS: Among the 140 patients examined, the incidence of positive cytology in the prelavage was 15 percent, and that in the postlavage was 9 percent, although it was 16 percent in either lavage. Among patients with curative resection, 10 percent had positive cytology. Seven characteristics were identified as features of tumors which are prone to exfoliate cells into the peritoneal cavity: 1) macroscopic peritoneal dissemination, 2) liver metastasis, 3) more than 20 ml of ascites, 4) ulcerated tumors without definite borders, 5) invasion of the serosal surface or beyond, 6) semiannular or annular shape, and 7) moderate or marked lymphatic invasion. In patients undergoing curative surgery, among these features, circumferential involvement was the only one correlated closely with positive cytology (P<0.02). Positive cytology was associated with a worse outcome. In patients who were resected curatively, the postcytology had a stronger influence on local recurrence than the precytology; the local recurrence rate in patients with positive postcytology was higher than in those with negative postcytology, regardless of the precytology. All patients with cancer cells in the peritoneal cavity at the end of surgery had recurrence. CONCLUSIONS: Seven characteristics were identified as risk factors for exfoliation of cancer cells into the peritoneal cavity in patients with colorectal cancer. These findings may be helpful for the choice of laparoscopic surgery in this era of increasing port-site metastases after laparoscopic procedure. The results of peritoneal lavage cytology at the end of surgery were correlated with the long-term postoperative outcome of colorectal cancer. Thus, meticulous follow-up and possibly adjuvant chemotherapy may be beneficial for patients with free cancer cells in lavage fluid, even after curative surgery.