Antibody seronegative human T-lymphotropic virus type III (HTLV-III)- infected patients with acquired immunodeficiency syndrome or related disorders

The human T-lymphotropic virus type III (HTLV-III) is the primary cause of the acquired immunodeficiency syndrome (AIDS) and related disorders (ARC). Prior studies have reported that nearly all symptomatic patients with AIDS or ARC manifest antibody to HTLV-III. This observation has engendered efforts to screen for HTLV-III, especially prior to blood donation, with assays for antibody to HTLV-III. We report the first two cases, one with AIDS and one with ARC, that are HTLV-III virus positive but antibody negative. Accurate diagnosis of HTLV-III infection in some cases may require direct virus culture or tests for antigen. In addition, lack of HTLV-III antibody may indicate an atypical clinical course of AIDS.     

Intraabdominal adhesion formation after preperitoneal dissection in the murine model

Background: The laparoscopic approach to hernia repair has been advocated by many as a potentially superior method of herniorraphy. Several techniques have been described, each with its own proposed advantages. These techniques involve different anatomic approaches, the most recent of which is the totally extraperitoneal approach (TEPA). One presumed advantage of the extraperitoneal approach is the avoidance of adhesion formation because the peritoneum is not entered and mesh is not placed in direct contact with intra-abdominal structures. We hypothesize, however, that when the peritoneum is dissected from the abdominal wall, it is partially devascularized, leading to scar formation and potential adhesion formation. This would suggest that the TEPA method of herniorraphy may not completely avoid the risks of intra-abdominal adhesion formation. Methods: After appropriate approval was obtained, 88 male Sprague-Dawley rats were divided into two equal groups. One group underwent laparotomy followed by careful blunt dissection of the peritoneum from the left abdominal wall. The control group underwent laparotomy without manipulation of the peritoneum. All animals were re-explored 14 days later, and the abdominal cavity was examined for adhesions. The type and location of any adhesion was recorded. Results: Adhesion formation occurred in 10 of 44 (23%) subjects in the peritoneal dissection group, compared with 3 of 44 (7%) in the nondissection group (p < 0.05). Conclusions: Dissection of the peritoneum from the overlying abdominal wall in the murine model leads to intra-abdominal adhesion formation. This suggests that peritoneal dissection in the TEPA method of herniorraphy may lead to intra-abdominal adhesion formation. Received: 13 January 1998/Accepted: 22 May 1998     

Improvement of pressure flow parameters with finasteride is greater in men with large prostates. Finasteride Urodynamics Study Group

PURPOSE: We assess the effect of finasteride, a 5alpha-reductase inhibitor, on objective voiding parameters in men with lower urinary tract symptoms and benign prostatic enlargement on digital rectal examination (known as clinical benign prostatic enlargement) in a double-blind placebo controlled multicenter study using strict standard pressure flow study techniques. MATERIALS AND METHODS: A modification of the Abrams-Griffiths nomogram was used by 1 reader to ensure that all patients met objective criteria for bladder outlet obstruction at baseline. After performing a pressure flow study patients with obstruction were randomized 2:1 to receive 5 mg. finasteride (81) or placebo (40) daily. A second pressure flow study was performed at month 12. At baseline and month 12 free urinary flow studies and transrectal ultrasound were performed, and International Prostate Symptom Score questionnaires were completed. Patients were treated between May 1994 and July 1996. RESULTS: Finasteride caused a significant decrease (-8.1 cm. water) in detrusor pressure at maximum flow (p <0.05 versus placebo p = 0.02), increase (+1.1 ml. per second) in maximum flow rate (p <0.05 versus placebo p = 0.02) and decrease (-22.8%) in prostate volume (p <0.05 versus placebo p <0.001). Men with prostates larger than 40 cc had greater improvement in detrusor pressure at maximum flow (between group difference -14.5 cm. water, 95% confidence interval -26.2 to -2.6, p = 0.02) and maximum flow rate (mean treatment effect +1.6 ml. per second, 95% confidence interval -0.2 to 3.0, p = 0.02) compared to those with prostates 40 cc or less (between group differences not significant). CONCLUSIONS: Finasteride treatment resulted in improvements in urodynamic parameters, which were greater in men with large prostates.     

Descending thoracic aortobifemoral bypass: an alternative approach for difficult aortic revascularization

Descending thoracic aortobifemoral bypass is an alternative inflow operation in cases in which standard aortobifemoral or axillobifemoral bypass is not an option. We performed descending thoracic aortobifemoral bypass for failed inflow operations in four patients, prior abdominal/pelvic radiation in two patients, poor quality distal aorta (extensive atherosclerotic disease or poor tissue quality) in two patients, and abdominal sepsis in two patients. Eight have had excellent results with patency at a mean follow-up of 38 months. There was no limb loss. One patient died of organ failure, and one patient with hypercoagulability developed a graft clot. A literature review disclosed that a descending thoracic aortobifemoral bypass was reported to have been performed in 203 patients, with most cases reported in the last decade. This procedure was the primary inflow operation in 42 per cent of cases. Indications for the operation included failed aortic grafts (38%), "hostile" abdomen (21%), infected aortic grafts (18%), and other (23%). The patency rate was 95 per cent at 6 months. Few long-term results are known, but the results appear to be durable. Descending thoracic aortobifemoral bypass is a useful operation in highly selected circumstances in which conventional methods of aortic reconstruction are not available.     

Intestinal obstruction from midgut volvulus after laparoscopic cholecystectomy

Congenital midgut malrotation, a rare anatomic anomaly that can lead to duodenal or small bowel obstruction, rarely is recognized beyond the first year of life. We report a case of unrecognized congenital midgut malrotation that resulted in midgut volvulus, causing intestinal obstruction and requiring emergent reoperation after laparoscopic cholecystectomy. This unusual complication, first reported in 1994, involved a 56-year-old man and resulted in cecal infarction recognized and treated on the second postoperative day. This second case describes a less acute postoperative course, with multiple bouts of partial bowel obstruction leading to two readmissions and finally resulting in a reexploration and definitive treatment on the 19th postoperative day. Received: 16 February 1999/Accepted: 22 March 1999     

Multidetector CT findings in patients with mesenteric ischaemia following cardiopulmonary bypass surgery

Objective:

To investigate CT findings in patients with pathologically proven mesenteric ischaemia post-cardiopulmonary bypass surgery and compare them with the control group of patients without ischaemia.

Methods:

68 patients were identified by a search of local surgical and pathological databases; these patients met the inclusion criteria of a laparotomy within 1 month of a procedure requiring cardiopulmonary bypass and a CT abdomen/pelvis within 1 week of the pathological diagnosis. Two radiologists independently reviewed the studies, evaluating 17 separate findings relating to the bowel, the vasculature or other structures; consensus was subsequently reached. The diagnostic value of CT findings was assessed using logistic regression.

Results:

52 of 68 patients had pathologically proven ischaemia. Portal venous gas, mesenteric venous gas and small bowel faeces sign all had specificities of >0.94 for ischaemia but low sensitivity (<0.27). Differential mural enhancement had high sensitivity (0.92) but poor specificity (0.50). The combination of pneumatosis, bowel loop dilatation and differential mural enhancement predicted bowel ischaemia with a probability of 98%. The hardest signs to interpret based on poor interreader kappa agreement were bowel wall thinning, mesenteric stranding and differential mural enhancement.

Conclusion:

A combination of CT signs was predictive of ischaemic bowel; however, the more specific findings lacked sensitivity. If clinical suspicion is high for bowel ischaemia, prompt surgical intervention is warranted, regardless of CT findings.

Advances in knowledge:

Arterial occlusion was uncommon and venous occlusion was not present, which is supportive of a predominantly non-occlusive aetiology for ischaemia in this patient group.Mesenteric ischaemia with resulting bowel infarction is a potentially life-threatening complication following cardio-pulmonary bypass (CPB) surgery. The frequency following such operations is rare (0.49–2.00%) [1–3]; however, the mortality from acute mesenteric ischaemia of any aetiology is high at 70–100%, even for patients managed in specialist tertiary referral centres [4–6]. Although there has been a recent move away from coronary artery bypass graft (CABG) surgery to percutaneous transluminal coronary intervention, there has been an increase in the number of complex CABG surgical procedures performed, e.g. CABG with mixed valve replacement. This, combined with an ageing patient population with associated increased co-morbidities and risk factors, may lead to a rise in the incidence of ischaemic bowel in patients following CPB surgery [3]. Furthermore, definitive radiological diagnosis is known to be difficult in such patients [7]. The most common CT findings lack specificity, whereas the more specific findings are rarely present [8], thus knowledge of such CT findings and their diagnostic value would be beneficial.Mesenteric angiography was previously considered the gold standard radiological test for the diagnosis of mesenteric ischaemia of any aetiology. Although this offers the additional benefit of treatment in certain cases [9], the technique is invasive, availability may be limited in the acute setting, and it may be challenging in unstable post-operative patients [10]. CT overcomes some of these issues and provides additional diagnostic information about the bowel wall, solid intra-abdominal organs and vessel walls. In our selected patient group, non-occlusive mesenteric ischaemia owing to hypoperfusion associated with a low cardiac output postoperatively would be expected to be more prevalent than occlusive ischaemia [11,12].There have been several studies with a small number of patients looking at the multidetector CT features of patients presenting with mesenteric ischaemia [7,9,13–15], but to our knowledge, apart from a small case series [16], there are no studies specifically investigating the CT signs of bowel ischaemia in a post-cardiac surgery cohort. Thus, the aim of our study was to investigate the CT findings following pathologically proven mesenteric ischaemia/infarction in a retrospective group of patients postcardiac bypass surgery and compare this with the known features of acute mesenteric ischaemia.