Central venous thrombosis and perioperative vascular access in adult intestinal transplantation

BACKGROUND

Venous access is crucial in intestinal transplantation, but a thrombosed venous system may prevent the use of central veins of the upper body. The incidence of venous thrombosis and the necessity to perform alternative vascular access (AVA) in intestinal transplant recipients have not been fully investigated.

METHODS

Records of adult patients who underwent intestinal transplantation between January 1, 2001, and December 31, 2009, were reviewed. Contrast venography was performed as pre-transplantation screening. Vascular accesses at the transplantation were categorized as I (percutaneous line via the upper body veins), II (percutaneous line via the lower body veins), and III (vascular accesses secured surgically, with interventional radiology, or using non-venous sites). Categories II and III were defined as AVA. Risk factors for central venous thrombosis and those for requiring AVA were analysed, respectively.

RESULTS

Among 173 patients, central venous obstruction or stenosis (<50% of normal diameter) was found in 82% (141 patients). AVA was required in 4.6% (eight patients: four in each category II and III). Large-bore infusion lines were placed via the femoral arteries in all category III patients without complications. Existing inferior vena cava filter and hypercoagulable states were identified as the risk factors for the use of AVA, but not for central venous thrombosis. Outcomes of patients who underwent AVA were similar to those of patients without AVA.

CONCLUSIONS

The majority of adult patients undergoing intestinal transplantation had at least one central venous stenosis or obstruction. The recipient outcomes were comparable when either standard vascular access or AVA was used for transplantation.

Pulmonary thromboembolism during adult liver transplantation: incidence, clinical presentation, outcome, risk factors, and diagnostic predictors

BACKGROUND

Intraoperative pulmonary thromboembolism (PTE) is an often overlooked cause of mortality during adult liver transplantation (LT) with diagnostic challenge. The goals of this study were to investigate the incidence, clinical presentation, and outcome of PTE and to identify risk factors or diagnostic predictors for PTE.

METHODS

Four hundred and ninety-five consecutive, isolated, deceased donor LTs performed in an institution for a 3 yr period (2004-6) were analysed. The standard technique was a piggyback method with veno-venous bypass without prophylactic anti-fibrinolytics. The clinical diagnosis of PTE was made with (i) acute cor pulmonale, and (ii) identification of blood clots in the pulmonary artery or observation of acute right heart pressure overload with or without intracardiac clots with transoesophageal echocardiography.

RESULTS

The incidence of PTE was 4.0% (20 cases); cardiac arrest preceded the diagnosis of PTE [75% (15)] and PTE occurred during the neo-hepatic phase [85% (17)], especially within 30 min after graft reperfusion [70% (14)]. Operative and 60 day mortalities of patients with PTE were higher (P<0.001) than those without PTE (30% vs 0.8% and 45% vs 6.5%). Comparison of perioperative data between the PTE group (n=20) and the non-PTE group (n=475) revealed cardiac arrest and flat-line thromboelastography in three channels (natural, amicar, and protamine) at 5 min after graft reperfusion as the most significant risk factors or diagnostic predictors for PTE with an odds ratio of 154.32 [95% confidence interval (CI): 44.82-531.4] and 49.44 (CI: 15.6-156.57), respectively.

CONCLUSIONS

These findings confirmed clinical significance of PTE during adult LT and suggested the possibility of predicting this devastating complication.

Two cases of variceal haemorrhage during living-donor liver transplantation

Some patients with cirrhosis experience rupture of venous varices before operation, and liver transplantation is a therapy of last resort for these patients. However, we have experienced two cases of intraoperative rupture in whom no abnormalities of the venous varices were seen on endoscopy before operation. One patient with ruptured gastrointestinal varices was treated by direct surgical ligation and the other with ruptured oesophageal gastric varices, spontaneously recovered with a Sengstaken-Blakemore tube. These cases suggest that acute variceal haemorrhage should always be considered as a possibility during living-donor liver transplantation in patients with a history of upper gastrointestinal bleeding. Careful observation of the nasogastic tube is important during clamping of the hepatic portal vein.

Hyperglycemia and the outcome of pediatric cardiac surgery patients requiring peritoneal dialysis

OBJECTIVE

To study the nature of the association between glycemia and ICU mortality in pediatric cardiac surgery patients treated with peritoneal dialysis (PD).

MATERIALS AND METHODS

Retrospective observational study in the ICU of a tertiary hospital involving forty pediatric cardiac surgery patients treated with PD. We selected patients requiring PD, extracted glucose measurements and nutritional intake data during ICU stay and calculated mean and maximum blood glucose values i) during ICU stay; ii) during dependence on PD; and iii) during independence from PD. We statistically assessed the relationship between glycemia-related variables and ICU mortality.

MEASUREMENTS AND RESULTS

Twenty-two patients treated with PD died (mortality 55%). In the PD cohort, 9725 blood glucose measurements were performed (every 3.3 hours on average). The mean glycemia during dependence on PD was significantly higher in non-survivors than survivors (p<0.0001), but not during independence from PD (p=0.49). The area under the receiver operator characteristic curve for the mean glycemia during dependence on PD was significantly greater than that obtained during independence from PD. Even after adjustment for severity of illness using multivariate logistic analysis, the mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality.

CONCLUSIONS

A higher mean blood glucose concentration during PD, but not during PD-free periods was associated with greater ICU mortality. Mean glycemia and calorie intake during PD were significant and independent predictors of ICU mortality.

Expression of the cadherin-11 gene is a discriminative factor between articular and growth plate chondrocytes

OBJECTIVE

Calcification of hypertrophic chondrocytes is the final step in the differentiation of growth plates, although the precise mechanism is not known. We have established two growth plate-derived chondrocyte cell lines, MMR14 and MMR17, from p53-/- mice (Nakamata T, Aoyama T, Okamoto T, Hosaka T, Nishijo K, Nakayama T, et al. In vitro demonstration of cell-to-cell interaction in growth plate cartilage using chondrocytes established from p53-/- mice. J Bone Miner Res 2003;18:97-107). Prolonged in vitro culture produced calcified nodules in MMR14, but not in MMR17. Factors responsible for the difference in calcification between the two cell lines may also be involved in the physiological calcification in growth plate.

DESIGN

Gene expression profiles of MMR14 and MMR17 were compared using a cDNA microarray to identify candidate genes involved in the calcification process.

RESULTS

Forty-five genes were identified as upregulated in MMR14, including the cadherin-11 (Cdh-11) gene. The expression of Cdh-11 in MMR14 was detected in cell-cell junctions, while no expression was observed in MMR17. Primary cultured chondrocytes from growth plate (GC) also expressed the Cdh-11, and the staining of Cdh-11 was observed in the late hypertrophic zone of growth plate. Cell aggregation assays showed that chondrocytes required Ca2+ to form nodules, and knockdown of the Cdh-11 gene expression using short interfering RNA inhibited the formation of calcified nodules in MMR14. The introduction of Cdh-11 into MMR17 failed to produce calcified nodules indicating that Cdh-11 is one, but not the sole, factor responsible for the production of calcified nodules.

CONCLUSION

Although the physiological role is still unclear, Cdh-11 is a discriminative factor between articular and growth plate chondrocytes.