Primary colonic lymphoma. Clinical presentation, histopathologic features, and outcome with combination chemotherapy.

Primary colonic lymphomas are rare, but we identified 15 cases at our institution between 1973 and 1992. They comprised 5.8% of all cases of gastrointestinal lymphoma (15 of 259) and 0.16% of all cases of colon cancer (15 of 9,193) during the last 20 years. The most common presenting symptoms were abdominal pain and weight loss (40% each). In seven patients (47%), a palpable abdominal mass was noted on the initial physical examination. The most frequent site of involvement was the cecum (73%). Histologically, six (40%) were classified as high-grade and nine (60%) as intermediate-grade non-Hodgkin's lymphoma. The tumors usually presented at an advanced stage: in 13 of 15 patients (87%), the lymphoma had spread to the adjacent mesentery, the regional lymph nodes, or both when first diagnosed. The 5-year survival rate was 27% for all patients and 33% (4 of 12) for patients treated with combination chemotherapy. Two patients relapsed after 8 years of complete remission. Primary colonic lymphomas have an aggressive behavior and only a marginal response to surgery and combination chemotherapy.

Intraluminal measurement of enteric mucosal perfusion: relationship to superior mesenteric artery flow during basal and postprandial states in the dog.

BACKGROUND: Several in vivo techniques that assess mucosal perfusion by intraluminal probes have recently been developed and validated, including laser Doppler flowmetry, reflectance spectrophotometry, and tonometry. METHODS: With these techniques, a canine model where the entire vascular supply to the jejunoileum was isolated as the superior mesenteric artery and vein was used to examine the relationship between enteric mucosal blood perfusion and adjusted decrements in arterial flow under fasting and postprandial conditions. RESULTS: Mucosal perfusion measured by laser Doppler flowmetry and reflectance spectrophotometry correlated linearly with decrements in superior mesenteric artery flow (r2 = 0.96 and 0.98, respectively); estimation of mucosal pH by tonometry decreased only after a critical level of arterial inflow was reached (less than 50% of baseline flow). Mucosal perfusion increased after the meal throughout the jejunoileum with unrestricted superior mesenteric artery flow. However, with restricted superior mesenteric artery flow, nutrient delivery to the jejunum was accompanied by increased mucosal perfusion at that level but by decreased perfusion in the distal ileum not exposed to nutrients. This latter response represents a distal to proximal redistribution of blood, i.e., an intramesenteric steal phenomenon. CONCLUSIONS: In vivo measurements of mucosal perfusion reflected changes in large mesenteric vessel blood flow. These intraluminal techniques discriminated between a normal and an impaired mesenteric circulation in an acute model and may have clinical application.

Endoscopic laser coagulation of radiation-induced mucosal vascular lesions in the upper gastrointestinal tract and proximal colon.

UNLABELLED: Endoscopic laser coagulation effectively controls bleeding from radiation-induced rectal vascular lesions. OBJECTIVE: To assess the outcome of endoscopic treatment of radiation-induced bleeding due to vascular lesions located proximal to the sigmoid colon. METHODS: We identified 15 consecutive patients with such proximal radiation enteropathy treated at our Institution with Nd:YAG laser between 1984 and 1991. Ten patients (66%) had gastric and/or small bowel involvement, and five (33%) had colonic involvement with or without more proximal lesions. Bleeding first appeared at a mean of 21.2 +/- 12.5 months after completion of radiotherapy. Mean duration of gastrointestinal bleeding before laser treatment was 7.6 +/- 4.6 months. RESULTS: After completion of laser therapy, bleeding ceased in nine (60%) patients, decreased in three (20%), and persisted in three (20%). The mean hemoglobin level increased from 8.4 +/- 0.5 g/dl to 10.4 +/- 0.6 g/dl after completion of laser treatments (p < 0.02). The mean number of transfusions per patient per year decreased from 10.5 +/- 2.8 to 0.9 +/- 0.7 (p < 0.01). No treatment-related complications or deaths occurred. CONCLUSIONS: Endoscopic laser coagulation of radiation-induced mucosal vascular lesions in the upper gastrointestinal tract and proximal colon appears to be safe and, in most cases, effective.

Endoscopic Nd:YAG laser coagulation of bleeding from radiation proctopathy.

Hematochezia from mucosal vascular lesions usually confined to the rectum represents an uncommon but problematic late complication of pelvic radiotherapy. We studied 47 patients with medically refractory hematochezia resulting from radiation-induced rectosigmoid mucosal vascular lesions. All lesions were endoscopically coagulated with Nd:YAG laser. Median duration of hematochezia before laser therapy was 11 months, despite previous medical treatment (98%) or bypass colostomy (6%). Within 3 to 6 months after laser treatment, the number of patients with daily hematochezia fell from 40 (85%) to 5 (11%; p < 0.001), and the median hemoglobin level increased from 9.7 gm/dl to 11.7 gm/dl (p < 0.001). Complications occurred in three patients (6%); no deaths occurred. The condition in six patients (12.8%) was not improved by laser treatment. Two patients (4%) ultimately required surgical treatment for bleeding control. On the basis of symptomatic, hematologic, and endoscopic responses, Nd:YAG laser photocoagulation controlled bleeding from radiation proctopathy in most patients with an acceptably low morbidity. Patients with sigmoid colon involvement responded less favorably. Endoscopic laser photocoagulation should be considered before surgical intervention for treatment of hematochezia from radiation proctopathy.

The clinical and endoscopic spectrum of the watermelon stomach.

The watermelon stomach is an uncommon but treatable cause of chronic gastrointestinal bleeding. We report our experience with the clinical and endoscopic features of 45 consecutive patients treated by endoscopic Nd:YAG laser coagulation. The prototypic patient was a woman (71%) with an average age of 73 years (range of 53-89 years) who presented with occult (89%) transfusion-dependent (62%) gastrointestinal bleeding over a median period of 2 years (range of 1 month to > 20 years). Autoimmune connective tissue disorders were present in 28 patients (62%), especially Raynaud's phenomena (31%) and sclerodactyly (20%). Atrophic gastritis occurred in 19 of 19 (100%) patients, with hypergastrinemia in 25 (76%) of 33 patients tested. Antral endoscopic appearances included raised or flat stripes of ectatic vascular tissue (89%) or diffusely scattered lesions (11%). Proximal gastric involvement was present in 12 patients (27%), typically in the presence of a diaphragmatic hernia. Endoscopic laser therapy after a median of one treatment (range of 1-4) resulted in complete resolution of visible disease in four patients (13%) and resolution of > 90% in 24 patients (80%). Hemoglobin levels normalized in 87% of patients over a median follow-up period of 2 years (range of 1 month to 6 years) with no major complications. Blood transfusions were not necessary after laser therapy in 86% of 28 initially transfusion-dependent patients. The characteristic clinical, laboratory, and endoscopic features allow for a confident diagnosis that can lead to successful endoscopic treatment.

Acute gastrointestinal bleeding. Experience of a specialized management team.

The initial experience of a specialized management team organized to provide expedient care for all acute major gastrointestinal bleeding in protocolized fashion at a large referral center is presented. Of the 417 patients, 56% developed bleeding while hospitalized. Upper gastrointestinal bleeding accounted for 82%. The five most common etiologies included gastric ulcers (83 patients), duodenal ulcers (67 patients), erosions (41 patients), varices (35 patients), and diverticulosis (29 patients). Nonsteroidal anti-inflammatory drugs were implicated in 53% of gastroduodenal ulcers. The incidence of nonbleeding visible vessels was 42% in gastric and 54% in duodenal ulcers. The rates of rebleeding were 24% (20 patients) in gastric ulcers and 28% (19 patients) in duodenal ulcers. Predictive factors for rebleeding included copious bright red blood, active arterial streaming, spurting, or a densely adherent clot. The rebleeding rate for esophagogastric varices was 57%. The mortality rate overall was 6% (27 patients), with rates varying from 3% (five patients) for gastroduodenal ulcers to 40% (14 patients) for esophagogastric varices. The morbidity rate for the entire patient population was 18% (77 patients), dominated by myocardial events (34 patients). The average length of hospitalization for gastroduodenal ulcers was 5 days, for diverticulosis 8 days, and for varices 10 days. The major efforts of a specialized Gastrointestinal Bleeding Team would be best directed at both reducing the morbidity associated with acute bleeding and reducing the overall cost of care.

The mechanisms and prevention of intravascular fluid loss after occlusion of the supraceliac aorta in dogs.

Mechanisms of intravascular fluid depletion after temporary occlusion of the supraceliac aorta were investigated in a canine model. During ischemia and reperfusion, hemodynamic parameters, superior mesenteric artery flow, intestinal mucosal perfusion, and mucosal permeability were monitored. After 12 hours of reperfusion, the volumes of intravenous electrolyte fluid required to maintain hemodynamic stability and fluid lost into the gastrointestinal tract and peritoneal cavity were measured. The distribution of total body water was analyzed by use of radionuclide dilution techniques. Group A animals underwent laparotomy only, group B had the supraceliac aorta occluded for 45 minutes, group C had superoxide dismutase administered after 45 minutes of aortic occlusion, and group D animals were exposed to mild hypothermia during a similar ischemia and reperfusion period. No significant difference was found in mean superior mesenteric artery flow or mucosal perfusion during ischemia among groups B, C, and D. During reperfusion superior mesenteric artery flow returned to values similar to control in all groups. Aortic occlusion increased mucosal permeability most significantly in group B (p less than 0.01). Mean intravenous fluid requirements (ml/mg) were the following: group A, 80 +/- 5; group B, 201 +/- 9 (p less than 0.01); group C, 116 +/- 7 (p less than 0.05); group D, 245 +/- 24 (p less than 0.05). Mean gastrointestinal fluid loss was highest in the hypothermic group and smallest if superoxide dismutase was given. Mean intracellular fluid volume was increased in groups B and D compared with group A (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Recent trends in the diagnosis and management of chronic intestinal ischemia.

This paper reviews the operative management over the past 27 years of 102 patients with chronic mesenteric ischemia, and summarizes recent clinical trends and ongoing research in this area. The most important trends in the diagnosis and management of chronic intestinal ischemia include: (1) increasing use of duplex ultrasound scanning in the initial evaluation of patients with possible intestinal angina; (2) rapidly evolving noninvasive clinical tests to assess mucosal perfusion (reflectance spectrophotometry, laser Doppler flow analysis, and tonometry); and (3) preferential use of antegrade mesenteric grafts or transaortic endarterectomy for mesenteric atherosclerotic occlusive disease. Surgical revascularization continues to provide excellent early relief of symptoms (93%) and a low late recurrence rate (10%). New noninvasive diagnostic tests for chronic intestinal ischemia and excellent results of surgical revascularization support a continued aggressive approach to the early recognition and treatment of patients with chronic intestinal angina. With the aging population, we anticipate that the number of patients with chronic intestinal ischemia will increase.

Phosphaturic effect of furosemide: role of PTH and carbonic anhydrase.

The first objective of this study was to examine the effects of furosemide on renal phosphate excretion in the presence and absence of a constant level of parathyroid hormone (PTH) while extracellular fluid volume was held constant. In the absence of PTH, furosemide did not significantly increase fractional phosphate excretion (FEP%, 4.2 +/- 2.7 to 6.2 +/- 1.9%; five dogs). In the presence of PTH, furosemide increased FEP% from 23.4 +/- 3.7 to 33.8 +/- 6.0% (P less .025; five dogs). Thus, the phosphaturia induced by furosemide was dependent on the presence of PTH. The second objective was to evaluate the hypothesis that furosemide exerts its phosphaturic effect through carbonic anhydrase inhibition, and therefore we tested for additivity of the phosphaturic effect of furosemide, and acetazolamide. In the presence of a constant level of PTH, acetazolamide increased FEP % from 24.5 +/- 1.8% to 40.7 +/- 5.1% P less than .025, five dogs. The subsequent administration of furosemide did not further increase FEP%, delta 3.3 +/- 8.9%; NS. Thus, the phosphaturic effect of furosemide was not additive to that of acetazolamide, indicating that acetazolamide and furosemide may share similar mechanisms for inhibiting phosphate reabsorption.