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Biomedical subjects

R Wassef

Publications and source records attributed to R Wassef.

13 recordsLinked to original sources
PubMed1989

Preliminary results of coloanal anastomosis.

Coloanal anastomosis after resection of the rectum is the ultimate procedure to preserve the patient's sphincter and avoid a permanent colostomy. Carcinoma of the midrectum, and sometimes of the lower third of the rectum, may not require excision of the pelvic floor and anus for cure. A colonal anastomosis was achieved in 38 patients in whom the indications for surgery were carcinoma in 29, recurrent or extensive adenomas in four, radiation proctitis in two, rectal fistula following radical cystectomy in one, secondary low Hartmann reconstruction after a failed attempt in one, and stenosis of a very low colorectal anastomosis in one. Twenty-six patients were men and 12 women, with a mean age of 62. Dukes' staging for carcinoma were A: 9, B: 7, C: 11, and two had a palliative resection. The mean distance from the anus was 6.0 cm. All had a temporary defunctioning colostomy. There were no postoperative deaths and 17 (45 percent) had postoperative complications, major in 7 (18 percent), minor in 10 (26 percent). Mean follow-up is now 40 months (range, 12 to 64 months). Among patients who underwent curative resection, three have had pelvic recurrences. Two of these patients died of widespread distant disease and one underwent abdominoperineal resection and is now free of disease. All others are alive with no evidence of disease. The colostomy was closed in all but six (16 percent). Two (palliative) died within the colostomy and the other four are awaiting closure. Anastomotic stricture was the most common long-term problem, occurring in 16 and requiring more than one dilatation in eight. Six months after closing the colostomy, the mean daily number of bowel movements is 3.8. Twenty-six (87 percent) are continent to solid stools, two are incontinent to solid stools, and 16 have to wear a pad to prevent soiling. All but one prefer their present status to having their colostomy. In selected cases of rectal carcinoma with little or no extramural spread, the authors estimate that resection and colonal anastomosis is a good alternative with acceptable function and a low rate of recurrent disease, which is comparable to complete rectal excision but avoids a permanent colostomy. However, it should not be a substitute for standard abdominoperineal resection for extensive lower rectal carcinoma or for a colorectal anastomosis when the latter is technically feasible.

Adult↗
PubMed1988

[Malignant colonic polyps: is polypectomy adequate treatment?].

The management of patients with endoscopically removed malignant intestinal polyps is controversial. The risk of residual disease should be assessed against the risk of a surgical operation. The authors report 35 cases of malignant polyps (5.5% of 641 colonoscopically removed adenomas). Sixteen patients had carcinoma in situ and received no further treatment and 19 had invasive carcinoma (sessile in 6, pedunculated in 13). Of these 19, 7 did not undergo surgery--because of old age in 2, minimal invasion in 3, a low rectal location in 1 and refusal in 1. Twelve patients (3 with sessile, 9 with pedunculated polyps) underwent a surgical resection, and residual disease was present in 3 (25%), 1 with positive nodes. Reported criteria of increased risk of residual disease--cancer in lymphatics or veins, incomplete excision, tumour at resection margin, sessile and villous tumours--were present in nine. All three patients with residual disease had microscopically involved margins of resection. The authors believe that the increased risk of recurrence justifies the risk associated with subsequent surgical resection unless the patient is otherwise a poor operative risk.

Adenoma↗
PubMed1987

Is preoperative colonoscopy in carcinoma a realistic and valuable proposition?

Colonoscopy was performed preoperatively in 100 consecutive patients as a prospective study to establish the feasibility of the procedure and its value, which was considered "adequate" when the colon remaining after surgical resection had also been examined preoperatively. Colonoscopy was adequate in 35 of 46 patients (76%) with malignant tumour located in the cecum and ascending and transverse colon, but in only 15 of 54 patients (28%) who had a tumour in the left colon or rectum. Synchronous malignant tumours were present in 2 patients, and 54 additional adenomas were discovered in 29 patients. These adenomas could be removed endoscopically in 13 patients and were included in the standard resection in 12. Extension of the planned operation was necessary in only four patients with synchronous adenomas. Routine preoperative colonoscopy to assess the presence of synchronous colonic tumours is more likely to be adequate in proximal or right-sided large-bowel tumours than in left-sided tumours because of the annular configuration of the latter. Because of the high rate (46%) of synchronous adenomas in adequate examinations, inadequate preoperative colonoscopy should be complemented by a repeat examination 3 to 6 months postoperatively in every patient with a malignant tumour of the large bowel.

Adenoma↗
PubMed1986

Rectal prolapse.

Explore the source record for details and available documents.

Anal Canal↗
PubMed1986

Transplantation of the small intestine.

Experimental use of cyclosporine in animal models following small intestinal transplantation is reviewed. The authors' techniques for monitoring allografts and harvesting the small bowel in humans for transplantation purposes are described.

Cyclosporins↗
PubMed1986

Small intestinal transplantation using cyclosporine. Report of a case.

A case of small intestinal allotransplantation is described. Cyclosporine and Solumedrol were used for immunosuppression. A hemolytic episode occurred, caused by anti-A antibodies derived from graft lymphocytes. Sudden severe encephalopathy developed on the ninth postoperative day, followed by intractable hypotension and death. Hepatic and splenic microinfarcts were identified on postmortem examination. Allograft rejection was identified by serial stomal biopsies and correlated with a rise in monocyte procoagulant activity, a potentially useful serologic marker of rejection. The absence of an anatomic circuit for recycling of cyclosporine did not alter serum radioimmunoassay/high-performance liquid chromatography ratios.

Adult↗
PubMed1985

Small intestinal transplantation. A closer reality.

The purpose of this study was to determine whether small intestinal transplantation could be considered as an alternative in the treatment of patients suffering from the short-bowel syndrome. The site of absorption of oral cyclosporine A was determined as were the changes that follow small intestinal transplantation. The interactions between the lipophilic cyclosporine A molecule and fat emulsion solutions used for total parenteral nutrition were investigated. Finally, a technique for harvesting the entire small bowel in man was developed. The absorption of oral cyclosporine A in normal dogs, and in bowel-resected, autotransplanted, and allotransplanted dogs was determined. Cyclosporine A levels were monitored in all animals. This demonstrated that cyclosporine A is absorbed through the small bowel and carried through the lymphatics; that absorption is decreased to 40 percent of normal after autotransplantation or allotransplantation without rejection. Rejection further hampers cyclosporine A absorption. Administration of olive oil alone enhances absorption of cyclosporine A. We also administered cyclosporine A IV to five dogs, with and without a concomitant infusion of fat emulsion solution (Intralipid). No changes in plasma cyclosporine A levels, in the clearance of cyclosporine A, or in the in vivo distribution of cyclosporine A were noted. Finally, dissections in six cadavers and in four brain-dead organ donors were performed, and a reproducible technique for harvesting the small bowel in man was established. In selected patients with the short-bowel syndrome, small intestinal transplant may be considered as an alternative therapy to home total parenteral nutrition.

Animals↗
PubMed1985

Cyclosporine absorption in intestinal transplantation.

The absorption of oral cyclosporine (CsA) was studied in a canine small intestinal transplantation model. Absorption of CsA was almost absent in bowel-resected dogs. Autotransplanted dogs showed a persisting malabsorption of CsA (mean peak of 687 +/- 348 ng/ml vs. 1683 +/- 154 ng/ml in control dogs). Allotransplanted dogs with normal graft histology showed a similar malabsorption (mean increase in CsA level: 833 ng/ml), whereas allotransplanted dogs with rejection of the graft showed a markedly decreased absorption (mean increase: 368 +/- 31 ng/ml). In two autotransplanted dogs pretreated with olive oil alone, CsA absorption increased over four weeks to a mean peak of 2215 +/- 5 ng/ml. We conclude that oral CsA is absorbed through the small intestine. Absorption of CsA is decreased after autotransplantation and allotransplantation, and rejection of the graft impedes it further. Regular administration of olive oil alone enhances absorption of oral CsA in a canine model.

Animals↗
PubMed1985

Pharmacokinetic profiles of cyclosporine in rats. Influence of route of administration and dosage.

This study was performed to determine the influence of different routes of administration and of variable doses of cyclosporine (CsA) on the pharmacokinetics of CsA in the rat. Seven groups of 4 adult female Lewis rats were given CsA once daily for 5 days: group 1: 5 mg/kg of CsA p.o. (by gavage); group 2: 10 mg/kg of CsA p.o.; Group 3: 5 mg/kg of CsA i.m.; group 4: 10 mg/kg of CsA i.m.; Group 5: 5 mg/kg of CsA s.c.; group 6: 10 mg/kg of CsA s.c., group 7: 10 mg/kg CsA i.p. CsA plasma levels were determined by RIA at 0, 2, 4, 6, 8, and 24 hr on days 1 and 4. Ease of administration was greatest in the s.c. groups (3 and 4), in which no anesthesia, no restraining device, and no special skills were required. Peak CsA levels varied greatly from group to group, as did trough levels and CsA bioavailability, as determined by the total area under the plasma CsA concentration-time curve. All groups exhibited great variation of CsA plasma level in the 24-hr period following administration, except group 3, in which the peak-to-trough difference was only 26.8% of peak level, as opposed to values over 60% in all other groups. We conclude that: (1) CsA may be administered to rats through different routes to achieve adequate plasma levels; (2) the route and dosage will greatly influence the pharmacokinetic profile of CsA; and (3) the SC route, in addition to being the easiest, provides reproducible and steady CsA plasma levels, with little variation over a 24-hr period.

Administration, Oral↗
PubMed1985

Experimental and clinical intestinal transplantation.

Before 1972 several attempts were made to perform small intestinal transplantation in man for the treatment of diseases leading to major losses of the small intestine. No patient had survived for more than 76 days despite intensive conventional immunosuppressants. Small intestinal allotransplantation has been investigated, experimentally, since 1959. Lillehei initially reported the results of allotransplantation of various lengths of small intestine in the canine model. Surgical techniques for successful allogeneic small intestinal transplantation as well as the methods for graft preservation, were clarified. Autotransplants of the total small bowel in dogs survived indefinitely. However, in dogs receiving total small intestinal allotransplants the mean survival period was 8-15 days. Both rejection and graft-versus-host disease have been implicated in the short survival of experimental animals. With the advent of cyclosporine and its known action against both rejection and graft-versus-host disease, we studied the results of parenteral cyclosporine on the survival of dogs following total small intestinal allotransplantation. Cyclosporine greatly prolongs survival to a mean of 103 days, following transplantation of the small bowel, compared to only 12 days in dogs not receiving any immunosuppressive agent. Two of the treated dogs lived for longer than 200 days and one dog lived for more than 400 days. Following this, we have developed a method of histological monitoring of the allograft by making two exterior isolated pouches of the allograft, representing the histological events leading to rejection of the in-continuity bowel.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMedDate not supplied

Surgical treatment of severe postshunt hepatic encephalopathy.

Hepatic encephalopathy is a major complication of portal-systemic shunts with an incidence ranging up to 52%. A small fraction of these patients are refractory to medical therapy. Shunt ligation and colonic procedures are the main surgical approaches. The goal of the latter is to diminish the colonic absorption of nitrogenous substances which are involved in the pathophysiology of hepatic encephalopathy. Six patients, whose average age was 55.7 +/- 2.6 years, were operated for severe postshunt encephalopathy requiring 4.3 +/- 0.9 admissions for a total duration of 76 +/- 26 days over 1-11 years. One patient had undergone a splenoral shunt and 5 had a portacaval shunt. One ligation of the shunt and 5 colon exclusions were performed. The average postoperative hospital stay was 21.5 +/- 3.9 days. The mean follow-up was 47 +/- 20 months. The patient with the shunt ligation remains free of encephalopathy 94 months after the procedure and has not bled from his esophageal varices. Among the 5 colon exclusion patients, there were 1 death and 3 complications. Three patients were completely relieved of their hepatic encephalopathy. One of those 3 died of a subarachnoid hemorrhage 28 months after the surgery. The fourth still needs medication to control a persistent, although improved, encephalopathy that required 2 further hospitalizations. Colon exclusion is a useful intervention in very selected cases. It has a lower operative mortality than total colectomy and the advantage over shunt ligation of not reestablishing hypertension in the portal system.

Hepatic Encephalopathy↗