Massive bowel resection

The antibiotic vancomycin induces complexation and aggregation of gastrointestinal and submaxillary mucins

Vancomycin, a branched tricyclic glycosylated peptide antibiotic, is a last-line defence against serious infections caused by staphylococci, enterococci and other Gram-positive bacteria. Orally-administered vancomycin is the drug of choice to treat pseudomembranous enterocolitis in the gastrointestinal tract. However, the risk of vancomycin-resistant enterococcal infection or colonization is significantly associated with oral vancomycin. Using the powerful matrix-free assay of co-sedimentation analytical ultracentrifugation, reinforced by dynamic light scattering and environmental scanning electron microscopy, and with porcine mucin as the model mucin system, this is the first study to demonstrate strong interactions between vancomycin and gastric and intestinal mucins, resulting in very large aggregates and depletion of macromolecular mucin and occurring at concentrations relevant to oral dosing. In the case of another mucin which has a much lower degree of glycosylation (~60%) - bovine submaxillary mucin - a weaker but still demonstrable interaction is observed. Our demonstration - for the first time - of complexation/depletion interactions for model mucin systems with vancomycin provides the basis for further study on the implications of complexation on glycopeptide transit in humans, antibiotic bioavailability for target inhibition, in situ generation of resistance and future development strategies for absorption of the antibiotic across the mucus barrier.

No gut syndrome: near total enterectomy

In adult patients, removal of the entire jejunum and ileum (a near total enterectomy (NTE)) is considered a non-survivable event as patients undergoing this procedure might also suffer from an underlying illness that will lead to bowel necrosis such as septic or cardiac shock and respiratory failure. Parenteral nutrition (PN) dependency with its associated complications and quality of life issues further complicates management decisions in this group of patients. In the following report, we discuss our institutional experience with NTE and present a comprehensive review of the literature with patients undergoing NTE with the establishment of bowel continuity and successful outcomes even in cases dating as far back as the 1950s, over a decade prior to the implementation of PN. Review of the literature revealed 26 cases of NTE. Most of these patients are young (46.7 years old), and 57 % are women. These patients were reported to be alive at 21 months of follow-up. In this report, we present an individual 51 months following NTE. We also document the oldest patient receiving an NTE (76 years old). Both of these patients are alive on home PN. In cases where there is hemodynamic stability and patients request to continue with further care, the possibility of a NTE with bowel continuity and life-long PN might be entertained.

Recycling of jejunal effluent to enable enteral nutrition in short bowel syndrome

A 41-year-old woman developed severe abdominal pain, distension and faeculent vomiting. CT of abdomen and pelvis revealed small bowel malrotation with a right paraduodenal hernia. At emergency laparotomy, a right paraduodenal hernia containing jejunum and ileum was identified. She had a viable duodenum with 50 cm of ischaemic proximal jejunum which was exteriorised as an end jejunostomy; 180 cm of infarcted jejunum and ileum was resected. The proximal end of 150 cm of healthy ileum was exteriorised as a closed mucous fistula and 50 cm distally a feeding ileostomy was constructed. On day 5 postoperatively, jejunal effluent began to be recycled via her feeding ileostomy and she never required parenteral nutrition. Despite having only 50 cm of jejunum proximal to her stoma, recycling of effluent enabled her electrolytes to remain normal. She put on weight postoperatively and proceeded to closure of her stomas at 6 months, not requiring laparotomy.

Systematic review of survival after acute mesenteric ischaemia according to disease aetiology

BACKGROUND

Differentiation of acute mesenteric ischaemia on the basis of aetiology is of great importance because of variation in disease progression, response to treatment and outcome. The aim of this study was to analyse the published data on survival following acute mesenteric ischaemia over the past four decades in relation to disease aetiology and mode of treatment.

METHOD

A systematic review of the available literature from 1966 to 2002 was performed.

RESULTS

Quantitative analysis of data derived from 45 observational studies containing 3692 patients with acute mesenteric ischaemia showed that the prognosis after acute mesenteric venous thrombosis is better than that following acute arterial mesenteric ischaemia; the prognosis after mesenteric arterial embolism is better than that after arterial thrombosis or non-occlusive ischaemia; the mortality rate following surgical treatment of arterial embolism and venous thrombosis (54.1 and 32.1 per cent respectively) is less than that after surgery for arterial thrombosis and non-occlusive ischaemia (77.4 and 72.7 per cent respectively); and the overall survival after acute mesenteric ischaemia has improved over the past four decades.

CONCLUSION

There are large differences in prognosis after acute mesenteric ischaemia depending on aetiology. Surgical treatment of arterial embolism has improved outcome whereas the mortality rate following surgery for arterial thrombosis and non-occlusive ischaemia remains poor.

Management of patients with a short bowel

There are two common types of adult patient with a short bowel, those with jejunum in continuity with a functioning colon and those with a jejunostomy. Both groups have potential problems of undernutrition, but this is a greater problem in those without a colon, as they do not derive energy from anaerobic bacterial fermentation of carbohydrate to short chain fatty acids in the colon. Patients with a jejunostomy have major problems of dehydration, sodium and magnesium depletion all due to a large volume of stomal output. Both types of patient have lost at least 60 cm of terminal ileum and so will become deficient of vitamin B₁₂. Both groups have a high prevalence of gallstones (45%) resulting from periods of biliary stasis. Patients with a retained colon have a 25% chance of developing calcium oxalate renal stones and they may have problems with D (-) lactic acidosis. The survival of patients with a short bowel, even if they need long-term parenteral nutrition, is good.

Home parenteral nutrition after near total enterectomy

Six patients with extreme short bowel syndrome (4.2 +/- 4.9 cm of residual small bowel) were provided home parenteral nutrition (HPN) for 14,397 days. The average age at onset of HPN was 38 years (18-64 years). Patients maintained body weight at 97% of ideal (86-112%) with mean serum albumin of 3.7 +/- 0.6 g/dL (normal 3.5-5.8 g/dL), serum transferrin of 341 +/- 104 mg/dL (normal 200-400 mg/dL), and mean serum pre-albumin of 27.5 +/- 12.6 mg/dL (normal 16.6-43 mg/dL). Hospital admission for HPN-related complications was required 10.3 times/patient for a total of 864 hospital days and was catheter related in 71% of episodes. Catheter sepsis occurred once per 436 catheter days and required catheter removal in only 33% of instances. Five patients were able to resume an oral diet, five had returned to work or school, and three were married with family. HPN allowed return to a quality productive life with acceptable morbidity following catastrophic massive bowel resection.

Should intestinal continuity be restored after massive intestinal resection?

We reviewed our experience with 32 patients who underwent massive intestinal resection to determine when intestinal continuity should be maintained. An enterostomy was created in 21 patients (66 percent) at the initial resection because of questionable bowel viability and an unstable condition or the need for colonic anastomosis. Intestinal continuity was restored in only 20 percent of these patients. In 11 patients (34 percent), intestinal continuity was maintained at the time of resection. Only four of these patients (36 percent) had a satisfactory long-term outcome. Overall, intestinal continuity was maintained in 10 of the 22 patients (45 percent) followed over the long-term. Three quarters of patients with intestinal remnants shorter than 3 feet had an enterostomy. We believe intestinal continuity should be restored at the time of massive resection only in carefully selected patients when bowel viability is ensured, remnant length is greater than 3 feet, and a colonic anastomosis is not required. Maintaining intestinal continuity eliminates the inconvenience of the stoma but may cause dietary restriction and perianal discomfort.

Warfarin resistance associated with intravenous lipid administration

Intravenous lipids have been shown to have varying effects on coagulation parameters. A patient with short bowel syndrome and recurrent thrombotic episodes who required both intravenous lipids and anticoagulation is described. A constant infusion of a soybean oil emulsion (Intralipid) in his parenteral nutrient solution was demonstrated to interfere with the anticoagulant effect of warfarin. Termination of the infusion and rechallenge with warfarin resulted in prolongation of his prothrombin time to the therapeutic range. Reinstitution of a lipid-free parenteral nutrition regimen has allowed for successful continuation of warfarin therapy.

An experimental evaluation of segmental reversal after massive small bowel resection

The technique of reversal of a distal segment of residual small intestine was applied to the management of massive resection. A controlled evaluation was carried out in dogs into the effects of segmental reversal on the proximal remnant after the distal 75 per cent of the small bowel had been resected. The variables studied were survival, body weight, glyceryl tri(palmitate-1-14C) absorption and mouth-to-caecum transit time. Animals subjected to resection alone had accelerated intestinal transit, poor absorption, serious weight loss and a high early mortality. It was clearly demonstrated that segmental reversal after resection produced marked and progressive delay in transit time from mouth to caecum, sustained improvement in fat absorption and body weight and enhanced survival.

Comparison of changes in intestinal length and circumference after 90 per cent bypass and 90 per cent resection

Compensatory hypertrophy was compared in rats that had undergone 90 per cent small intestinal resection and rats that had undergone 90 per cent small intestinal bypass. Increases in intestinal length and circumference occurred rapidly in both groups and were virtually identical. Lengthening was more pronounced in the jejunum; increase in circumference was greater in the ileum. Increases in length and circumference of the appendix were seen in both experimental groups. These studies suggest that compensatory hypertrophy can occur in patients after either intestinal bypass or resection, and that patients with bypasses have a less difficult postoperative course because of their preexisting obesity.

Some observations on the behaviour of isolated and interposed jejunal and ileal segments in the rabbit

Segments of jejunum and distal ileum of varying lengths and different vascular supply were isolated and interposed iso- and antiperistaltically. Pressures proximal to the interposed segment were recorded with a fine, soft, open-tipped cathether introduced via a Mann-Bollman fistula. The distal ileal segments supplied by a single vessel exhibit an unpredictable high degree of tone in some cases, and when these segments were interposed they caused a high degree of partial obstruction irrespective of whether they were interposed iso- or antiperistaltically. Distal ilcal segments supplied two or more vessels interposed antiperistaltically caused a degree of obstruction related to their lengths, and interposed isoperistaltically they caused no obstruction.Jejunal single-vessel segments of both polarities exhibited low obstructive qualities. Antiperistaltic jejunal segments of two or more vessels supply behaved in a similar manner to corresponding ileal segments in that the degree of obstruction was related to the length of the segment. Isoperistaltic segments supplied bt two or more vessels caused no obstruction.Possible mechanisms accounting for the differing findings in jejunum and ileum are discussed.Some clinical applications are discussed.