[Splenic abscesses: From diagnosis to therapy]

Splenic abscess is septic collection which occurs after haematogenous spread or local dissemination. Splenic abscess is an uncommon and rare condition, more frequently affecting male and immunocompromised patients. There are no guidelines regarding its diagnosis and management. Computed tomography (CT) scan is highly sensitive and specific (95% and 92%, respectively) in the diagnosis of splenic abscess. Diagnosis is based on blood cultures which are positive in 24 to 80% of cases. Bacterial growth culture of abscess after drainage is more efficient (50-80%) and can be performed after surgery or percutaneous drainage under imaging, including CT scan. Microorganisms involved are frequently enterobacteriaceae, gram-positive cocci and anaerobes. This particular ecology leads to an empiric broad-spectrum antibiotic therapy, with a variable duration, from 10days to more than one month. Management remains very close to the one applied in case of liver abscesses. The role of splenectomy in the prevention of recurrence remains controversial. We reviewed the literature regarding splenic abscesses, from diagnosis to therapy.

[Dietary advice for treatment of inborn errors of metabolism in adult neurology: principes and limitations]

Special diets can be an efficient treatment for certain inborn errors of metabolism. Regimens applicable in adult neurology include low protein diet (phenylketonuria, homocystinuria, urea cycle disorders, organic acidurias), low fatty acid diets (fatty acid B oxidation defects, adrenomyeloneuropathy, Refsum's disease) and ketogenic diet (pyruvate dehydrogenase deficiency, glucose transporter (GLUT1) deficiency, refractory epilepsy). Although, these regimens can be very efficient in some instances, withdrawal and nutrient deficiencies are major problems encountered.

[Urea cycle disorders in adult patients]

INTRODUCTION

Urea cycle disorders (UCD) usually present after 24 h to 48 h of life with failure to thrive, lethargy and coma leading to death, but milder forms may occur from infancy to adulthood.

STATE OF THE ART

Survival of children with UCD has significantly improved and the need for transitional care to adulthood has emerged. Adult onset UCD present with chronic or acute neurological, psychiatric and digestive symptoms associated with protein avoidance. Ornithine transcarbamylase (OTC) deficiency, which is inherited as an X-linked disorder, is the most well-described UCD in adults. Acute decompensations associate the triad of encephalopathy, respiratory alkalosis and hyperammonemia. Acute encephalopathy is characterized by brain edema, which is life-threatening without treatment. Specific urea cycle enzyme deficiency can be suspected in the presence of abnormal plasma amino acids concentrations and urinary excretion of orotic acid. A measurement enzyme activity in appropriate tissue, or DNA analysis if available, is required for diagnosis. Treatment requires restriction of dietary protein intake and the use of alternative pathways of waste nitrogen excretion with sodium benzoate and sodium phenylbutyrate. Patients with acute forms may need hemodialysis or hemodiafiltration. Therapeutic goals for OTC deficiency are to maintain plasma ammonia<80 micromol/L, plasma glutamine<1,000 micromol/L, argininemia 80-150 micromol/L and branched chain amino acids within the normal range, in order to prevent episodes of potentially lethal acute hyperammonemia.

CONCLUSION

Potentially fatal acute hyperammonemia may occur in male or female patients at any age. Ammonia should be measured promptly in case of acute neurological and psychiatric symptoms or coma.

Thymidine phosphorylase gene mutations in patients with mitochondrial neurogastrointestinal encephalomyopathy syndrome

The mitochondrial neurogastrointestinal encephalomyopathy (MNGIE) syndrome is characterized by the association of gastrointestinal and neurological symptoms. It is a rare autosomal recessive mitochondrial disorder with multiple mitochondrial DNA deletions and/or depletion. It is caused by thymidine phosphorylase (TP) gene mutations resulting in a complete abolition of TP activity. We tested 31 unrelated patients presenting either with a complete MNGIE syndrome (8 patients), a severe intestinal pseudo-obstruction (10 patients), and multiple deletions and/or depletion of mitochondrial DNA (13 patients). All the tested patients presenting with a complete MNGIE had increased thymidine levels in plasma and urine, and no TP activity. The group with pseudo-obstruction syndrome had normal or partial reduction of TP activity. We found pathogenic mutations on TP gene only in the MNGIE syndrome group: all the MNGIE patients were compound heterozygous or homozygous for mutations in the TP gene. Eight of these mutations are yet unreported, confirming the lack of genotype/phenotype correlation in this syndrome. Enzymatic activity and thymidine level are thus rapid diagnosis tests to detect MNGIE affected patients prior to genetic testing for patients with gastrointestinal symptoms.

Prognostic factors after surgery of primary resectable gastrointestinal stromal tumours

AIMS

To analyse the prognostic factors of gastrointestinal stromal tumours (GIST) after a complete resection of the primary tumour.

PATIENTS AND METHODS

Fifty-nine patients who underwent a complete initial resection of a GIST were studied. Peritumoral resections (PTR) were compared to segmental organ resections (SOR). Overall survival (OS) and the disease-free survival (DFS) were calculated using the Kaplan-Meier method.

RESULTS

Primary sites were: stomach (25), small intestine (22), rectum (7), duodenum (5). Two patients had nodal involvement. The median follow-up was 45 months. Local DFS was significantly better after SOR compared to PTR (median 63 vs. 11 months, respectively, p<0.001). Univariate analysis for OS identified the grade (p=0.005) and size (p=0.02) as prognostic factors. Only a high histologic grade was an independent factor (p=0.02) in the multivariate analysis. Out of 49 patients who relapsed, the first recurrence was local only in 12, local and distant in 10 and distant only in 27; only one had a lymph node failure. Recurrences were accessible to curative surgery in 22 cases. OS of patients submitted to complete resection of their recurrence was significantly better than patients whose recurrence could not be resected (median 52 vs. 12 months, respectively, p<0.001).

CONCLUSION

Complete surgery without rupture remains the mainstay of treatment in patients with localized, resectable disease. A peri-tumoral resection confers a high risk of local recurrence and should be avoided. Lymphadenectomy is not systematic. Grade is the main prognostic factor for OS and can be a decision marker for adjuvant treatment with Gleevec.

Net digestive absorption and adaptive hyperphagia in adult short bowel patients

BACKGROUND AND AIMS

Intestinal adaptation after small bowel resection in humans is debated. We have quantified in adult short bowel (remnant small bowel length <2 m) patients oral intake and net digestive absorption and their evolution over time.

PATIENTS AND METHODS

Oral intake and faecal output were studied over three days in 90 patients (39 and 51 without or with parenteral nutrition, respectively) and in 14 patients in early (<6 months) and late (>6 months) periods after digestive continuity. Nitrogen and fat output were measured using chemiluminescence and Van de Kamer techniques, respectively.

RESULTS

In the whole group, 81% of patients had hyperphagia (spontaneous oral intake >1.5 x resting energy expenditure), independently and negatively related to fat absorption (p<0.01) and body mass index (p<0.001) but not braked by the presence of parenteral nutrition. Protein and fat absorption were related to small bowel length. We observed, in the late in comparison with the early period after digestive continuity: an increase in oral intake (1.6 v 2.3 resting energy expenditure), decrease in stool weight/oral intake ratio, no reduction in per cent fat absorption, and protein absorption improvement associated with a significant increase in the amount of protein absorbed (40 v 64 g/day; p<0.05), both being correlated with remnant small bowel length (p<0.01).

CONCLUSIONS

This study confirms an adaptive hyperphagia in adult short bowel patients. Over time, hyperphagia and amount of protein absorbed increased, the latter being related to remnant small bowel length, indicating a behavioural adaptation that allows expression of intestinal absorptive adaptation.

[Intestinal failure]

Intestinal failure is defined as the reduction in the functioning gut mass below the minimal amount necessary for the absorption of nutrients and a normal nutritional status. The main cause of chronic intestinal failure in adults is short bowel syndrome secondary to mesenteric ischemia. In short bowel the remnant bowel length is inferior to 200 cm. The two other causes of intestinal failure are extensive small bowel mucosal diseases and chronic intestinal pseudo-obstruction. The reference treatment of severe chronic intestinal failure is home parenteral nutrition. The main alternate for irreversible intestinal failure is small bowel transplantation, isolated or combined to liver transplantation.

Postabsorptive plasma citrulline concentration is a marker of absorptive enterocyte mass and intestinal failure in humans

BACKGROUND & AIMS

No blood marker assessing the functional absorptive bowel length has been identified. Plasma citrulline, a nonprotein amino acid produced by intestinal mucosa, is one candidate. We tested this hypothesis in adult patients with the short-bowel syndrome, whose condition can lead to intestinal failure.

METHODS

In 57 patients, after a minimal follow-up of 2 years subsequent to final digestive circuit modification, postabsorptive citrulline concentration was measured and parenteral nutrition dependence was used to define permanent (n = 37) and transient (n = 20) intestinal failure. Absorptive function, studied over a 3-day period, was evaluated by net digestive absorption for protein and fat (n = 51). Relations between quantitative values were assessed by linear regression analysis and cutoff citrulline threshold, for a diagnosis of intestinal failure by linear discriminant analysis. Cox model was used to compare citrulline threshold and anatomic variables of the short bowel as indicators of transient as opposed to permanent intestinal failure.

RESULTS

In patients with short-bowel syndrome, citrulline levels were lower than in controls (n = 51): 20 +/- 13 vs. 40 +/- 10 micromol/L (mean +/- SD), respectively (P < 0.001). After multivariate analysis, citrullinemia was correlated to small bowel length (P < 0.0001, r = 0.86) and to net digestive absorption of fat, but to neither body mass index nor creatinine clearance. A 20-micromol/L threshold citrullinemia, (1) classified short bowel patients with permanent intestinal failure with high sensitivity (92%), specificity (90%), positive predictive value (95%), and negative value (86%); and (2) was a more reliable indicator (odds ratio, 20.0; 95% confidence interval, 1.9-206.1) than anatomic variables (odds ratio, 2.9; 95% confidence interval, 0. 5-15.8) to separate transient as opposed to permanent intestinal failure.

CONCLUSIONS

In patients with short-bowel syndrome, postabsorptive plasma citrulline concentration is a marker of functional absorptive bowel length and, past the 2-year adaptive period, a powerful independent indicator allowing distinction of transient from permanent intestinal failure.

Duodenal vs. gastric administration of labeled leucine for the study of splanchnic metabolism in humans

Low-rate (6 ml/h) intragastric infusion of stable, isotope-labeled amino acids is commonly used to assess the splanchnic handling of amino acids in humans. However, when used in the postabsorptive state, this method yields unreliable plasma isotopic enrichments, with a coefficient of variation >10%. In this metabolic condition, we confirmed in six subjects that an intragastric infusion of L-[(2)H(3)]leucine at 6 ml/h yields an unreliable isotopic steady state in plasma amino acids with a coefficient of variation of 43 +/- 12% (mean +/- SD). In five additional subjects, we assessed the effects of 1) increasing the rate of delivery of a leucine tracer in an isotonic plasmalike solution at 240 ml/h into the gastric site, and 2) changing the site of infusion from gastric to duodenal with this same high rate of delivery. In contrast to the gastric route, and regardless of the rate of delivery, only the intraduodenal route allowed 1) isotopic plasma steady state (i.e., coefficients of variation were <10%: 5 +/- 3%), and 2) reproducible leucine extraction coefficients (22 +/- 5%). We conclude that an infusion site that bypasses the gastric emptying process, i.e., the duodenal route, along with delivery of a plasmalike solution, is necessary to reach isotopic steady state in plasma when labeled leucine is infused into the gastrointestinal tract in the postabsorptive state.

Prevalence of liver disease and contributing factors in patients receiving home parenteral nutrition for permanent intestinal failure

BACKGROUND

Liver cholestasis can be a life-threatening complication during home parenteral nutrition and may lead to combined liver-intestinal transplantation.

OBJECTIVE

To assess the prevalence of home parenteral nutrition-related liver disease and its contributing factors in patients with permanent intestinal failure.

DESIGN

Prospective cohort study.

SETTING

Two approved home parenteral nutrition centers.

PATIENTS

90 patients with permanent intestinal failure who were receiving home parenteral nutrition were enrolled from 1985 to 1996.

INTERVENTION

Clinical, biological, endoscopic, and ultrasonographic follow-up. Histologic examination of the liver was done in 57 patients (112 liver biopsies).

MEASUREMENTS

The Kaplan-Meier method was used to determine the actuarial occurrence of chronic cholestasis and complicated home parenteral nutrition-related liver disease (bilirubin level > or =60 micromol/L [3.5 mg/dL], factor V level < or =50%, portal hypertension, encephalopathy, ascites, gastrointestinal bleeding, or histologically proven extensive fibrosis or cirrhosis). Contributing factors were assessed by using univariate and multivariate (Cox model) analysis.

RESULTS

58 patients (65%) developed chronic cholestasis after a median of 6 months (range, 3 to 132 months), and 37 (41.5%) developed complicated home parenteral nutrition-related liver disease after a median of 17 months (range, 2 to 155 months). Of these patients, 17 showed extensive fibrosis after 26 months (range, 2 to 148 months) and 5 had cirrhosis after 37 months (range, 26 to 77 months). The prevalence of complicated home parenteral nutrition-related liver disease was 26%+/-9% at 2 years and 50%+/-13% at 6 years. Six patients died of liver disease (22% of all deaths). In multivariate analysis, chronic cholestasis was significantly associated with a parenteral nutrition-independent risk for liver disease, a bowel remnant shorter than 50 cm in length, and a parenteral lipid intake of 1 g/kg of body weight per day or more (omega-6-rich long-chain triglycerides), whereas complicated home parenteral nutrition-related liver disease was significantly associated with chronic cholestasis and lipid parenteral intake of 1 g/kg per day or more.

CONCLUSION

The prevalence of complicated home parenteral nutrition-related liver disease increased with longer duration of parenteral nutrition. This condition was one of the main causes of death in patients with permanent intestinal failure. Parenteral intake of omega-6-rich long-chain triglycerides lipid emulsion consisting of less than 1 g/kg per day is recommended in these patients.

Long-term survival and parenteral nutrition dependence in adult patients with the short bowel syndrome

BACKGROUND & AIMS

The short bowel syndrome (SBS) may be associated with either transient or permanent intestinal failure, presently treated by parenteral nutrition (PN). Survival and PN-dependence probabilities, taking into account both small bowel remnant length and the type of the digestive circuit of anastomosis, are not known in adult SBS patients. The aim of this study was to assess such prognostic factors.

METHODS

A total of 124 consecutive adults with nonmalignant SBS were enrolled from 1980 to 1992 at 2 home PN centers. They were analyzed for survival and PN-dependence probabilities using the Cox model and for PN dependence using linear discriminant analysis. Data were updated in April 1996.

RESULTS

Survival and PN-dependence probabilities were 86% and 49% and 75% and 45% at 2 and 5 years, respectively. In multivariate analysis, survival was related negatively to end-enterostomy, to small bowel length of <50 cm, and to arterial infarction as a cause of SBS, but not to PN dependence. The latter was related negatively to postduodenal small bowel lengths of <50 and 50-99 cm and to absence of terminal ileum and/or colon in continuity. Cutoff values of small bowel lengths separating transient and permanent intestinal failure were 100, 65, and 30 cm in end-enterostomy, jejunocolic, and jejunoileocolic type of anastomosis, respectively.

CONCLUSIONS

In adult SBS patients, small bowel length of <100 cm is highly predictive of permanent intestinal failure. Presence of terminal ileum and/or colon in continuity enhances both weaning off PN and survival probabilities. After 2 years of PN, probability of permanent intestinal failure is 94%. These rates may lead to selection of other treatments, especially intestinal transplantation, instead of PN, for permanent intestinal failure caused by SBS.

Leiden factor V mutation in four patients with small bowel infarctions

The Leiden factor V mutation is observed in 20% of unexplained lower limb venous thromboses and involves substitution of the arginine residue at position 506 by glutamine (R506Q). It is known to decrease the anticoagulant activity of activated protein C. This case report describes 4 cases of small bowel infarction (SBI) associated with the presence of this mutation. Two cases of arterial and 2 cases of venous SBI were observed. Extensive assessment excluded the usual causes of SBI and plasma hypercoagulation syndrome (antithrombin III, protein C, and protein S deficiency and myeloproliferative syndrome). An abnormal resistance to activated protein C was observed. Molecular analysis consisting of polymerase chain reaction amplification and digestion with MnlI showed that 2 patients were heterozygous and 2 were homozygous for the R506Q mutation. Despite familial history of thrombosis in only 1 patient, first- and second-degree relatives of 2 patients also had the presence of the mutation. Examination for the presence of abnormal resistance to activated protein C should be part of the etiological assessment of SBI. Its presence may warrant consideration of long-term anticoagulant therapy, especially for patients with shortened small bowel who are treated by home parenteral nutrition with deep venous access.