The role of ultrasonography in determining central venous patency in patients undergoing bowel transplantation.

Ultrasonography (US) is an attractive alternative for invasive studies to evaluate venous patency. However, little data exist concerning the usefulness of US in patients undergoing bowel transplantation. Twenty-five adult patients with bowel transplantation were retrospectively identified with both US and contrast venography (VG) performed preoperatively. The median age was 43 yr, and the median duration of total parenteral nutrition was 36 months. The vessels were evaluated as positive with ≥ 50% stenosis. Among the internal jugular veins and the subclavian veins examined with US (96% of the all sites) and with VG (69%), 66 venous sites were available for comparison. VG confirmed positive in 42% (28/66), while US found positive in 27% (18/66); US had three false positives and 13 false negatives, giving the sensitivity of 54% (95% confidence interval [CI], 34-72) and the specificity of 92% (CI, 77-98). The positive and the negative likelihood ratios weighted by prevalence (42%) were 5 (CI, 1.7-14.3) and 0.37 (CI, 0.23-0.60), respectively. In addition, VG confirmed stenosis in 32% of the right and 50% of the left brachiocephalic veins and 41% of the superior vena cava. US is not a reliable method for assessing the upper body venous system of patients undergoing bowel transplantation.

Monitoring immune function during tacrolimus tapering in small bowel transplant recipients.

Long term use of immunosuppressants impacts the cardiovascular system and increases the risk of infection and malignancy. To effectively reduce immunosuppression in a transplant recipient a tool is needed to directly monitor the level of immune function. The Cylex(R) Immune Cell Function Assay, approved by the FDA for the assessment of cell-mediated immunity, shows promise as an objective measure of a transplant recipient's immune function. In a blinded retrospective study, the immune function was compared to clinical courses and histological examinations of biopsies of 20 small bowel transplant recipients during periods of immunosuppressant tapering. Eight patients with no major adverse events or changes of immunosuppressive therapy had moderate to low immune function and were categorized as immunologically and clinically stable. Twelve patients displaying strong immune responses were immunologically and clinically volatile requiring addition of steroids and or OKT3. Results validate the clinical utility of the Cylex Immune Cell Function Assay as an objective tool for assessing immune function. By evaluating immune function, physicians now can identify those patients who are candidates for minimization of immunosuppressant therapy, manage the timing and rate of immunosuppressant weaning and be forewarned of increased patient risk.

De novo malignancies after intestinal and multivisceral transplantation.

BACKGROUND: Maintenance immunosuppression required after organ transplantation creates a permissive environment in which cancer cells can proliferate because of lack of natural immunologic surveillance. With more than a decade of clinical experience, this report is the first to address the risk of de novo cancer after intestinal transplantation. METHODS: A total of 168 consecutive intestinal transplant recipients (86 children and 82 adults) were studied, of whom 52% were male and 91% were white. Surveillance, Epidemiology, and End Results data was used to count expected rates of de novo cancers in the general population matched for age, sex, and length of follow-up. RESULTS: With a mean follow-up of 47+/-41 months, 7 (4.2%) patients developed nonlymphoid de novo cancer, with a cumulative risk of 3% at 5 years and 28% at 10 years. Of these malignancies, one was donor-driven adenocarcinoma. With 0.58 being the expected rate of malignancy for the general population, the risk among intestinal recipients was 8.7 times higher (P =0.01). Such morbidity was significantly higher (50 times) among younger patients (<25 years), with a slight male preponderance. Induction immunosuppression was associated with early onset of de novo cancer. Patient survival after diagnosis of de novo cancer was 72% at 1 year, 57% at 2 years, and 29% at 5 years. CONCLUSION: With conventional immunosuppression, intestinal recipients are at a significantly higher risk of developing de novo cancer when compared with the general population. Thus, a novel tolerogenic immunosuppressive strategy has been recently implemented to reduce the lifelong need for immunosuppression.