Modified Multivisceral Transplantation with Native Spleen Removal in Rats.

BACKGROUND: Modified multivisceral transplantation (MMVTx) refers to the use of a graft that includes all abdominal organs except the liver. The use of this type of transplant in children and adults expanded over the last years with good results. However, long-term survival in experimental models has not been reported. Our aim is to describe in detail some technical modifications of MMVTx to obtain long-term survival. MATERIALS AND METHODS: Syngeneic (Lewis-Lewis) heterotopic MMVTx was performed in 16 male rats (180-250 g). All procedures were performed under isoflurane anesthesia. The graft consisted of stomach, duodenopancreatic axis, spleen, and small bowel. The vascular pedicle consisted of a conduit of aorta, including the celiac trunk and the superior mesenteric artery (SMA), and the portal vein (PV). The engraftment was performed by end-to-side anastomosis to the infra-renal cava vein and aorta. After reperfusion, the graft was accommodated in the right side of the abdomen, and a terminal ileostomy performed. The native spleen was removed. RESULTS: Donor and recipient time was 39 ± 4.4 minutes and 69 ± 7 minutes, respectively; venous and arterial anastomosis time was 14 ± 1 minutes and 12.3 ± 1 minutes, respectively. Total ischemia time was 77.2 ± 7.9 minutes. Survival was 75% (12/16), six were sacrificed after 2 hours, and six were kept alive for long-term evaluation (more than 1 week). CONCLUSION: Long-term survival is reported after heterotopic MMVTx in rats. The heterotopic MMVTx with native spleen removal would potentially improve the existent models for transplant research. The usefulness of this model warrants further confirmation in allogeneic experiments.

Hepatocellular Carcinoma: Referral to a Transplantation Unit.

Aim Hepatocellular carcinoma (HCC), although being infrequent, is the second-most common primary hepatic malignancy in children, after hepatoblastoma (HB). The prognosis is very poor. We present our series of children with HCC referred to our transplant unit to be assessed as candidates for liver transplantation (LT). Methods A retrospective review of HCCs referred to our transplant unit in the past 20 years (1994-2015) was performed. Age at diagnosis, disease-free survival, location of recurrence, initial treatment, secondary treatment, and mortality were noted. Main Results Ten patients (8 boys, 2 girls) met the inclusion criteria. Median age at diagnosis was 11.5 years (0.5-14). HCC was associated with tyrosinemia in two patients, while the tumor developed in absence of previous liver disease in eight. Seven children attempted tumor resection earlier elsewhere. LT was not considered suitable in six patients due to extrahepatic tumor extension and finally it was performed in four (two with tyrosinemia and two with "de novo" HCC). Only one of the transplants was primary, and the other three were performed as rescue therapy. After 78 (66-90) months of follow-up, the two patients with tyrosinemia remain alive and disease free, while the other two had distant relapses, 35 and 37 months after LT, respectively, and finally died due to tumor progression. Conclusions HCC is a rare, very aggressive tumor in children who has a very poor prognosis. Our results suggest the need for new strategies. Early referral of all cases to highly specialized centers with a liver transplant unit and perhaps a more liberal use of LT, even for selected, apparently resectable cases, are possible options.

Severe tracheobronchial injuries: our experience.

INTRODUCTION: Severe tracheobronchial injuries (TBI) in children are usually traumatic or iatrogenic. However, they can also be caused by mediastinal infections that lead to critical situations. We herein report our experience in the treatment of these lesions. METHODS: A retrospective study was conducted for patients treated at our center from 2008 to 2014. TBI was diagnosed by imaging studies and bronchoscopy. Treatment was initially conservative (drainage of air and secretions, mechanical ventilation with minimal pressures, and an early extubation) with a limited use of surgical procedures whenever necessary. RESULTS: A total of 10 patients (7 males and 3 females) with a median age of 7.5 years (range, 3-17 years) suffered TBI. The mechanism was traumatic in six (three accidental and three iatrogenic) and mediastinal infection in four (three mycotic and one bacterial abscesses). All traumatic cases responded to conservative measures, except one iatrogenic lesion, which was surgically repaired. There were no complications or residual damages. Two patients with mediastinal infection presented with sudden cardiorespiratory arrest, one with hemoptysis caused by an arteriotracheal fistula and the other because of carinal rupture. Both died before any therapeutic measures could be taken. The other two patients were treated, one with previous extracorporeal membrane oxygenation support, underwent arterial embolization, but ultimately died, and the other one survived, but required esophagectomy and creation of a thoracostome for secondary wound closure of the bronchocutaneous fistula. CONCLUSION: Conservative treatment with gentle respiratory support suffices in most traumatic cases of TBI. Infectious abscesses with involvement of adjacent structures sometimes require complex surgery and are life-threatening.

Stool calprotectin monitoring after small intestine transplantation.

BACKGROUND: Small intestine transplantation is the only life-saving therapy available for patients with intestinal failure and life-threatening complications of parenteral nutrition, but it is still plagued by high levels of early acute rejection. The ability to diagnose rejection noninvasively, ideally before pathologic manifestations, would be a major advance in the care of intestinal transplant patients. METHODS: We measured calprotectin levels in 732 stool samples collected, analyzed over from 72 patients having undergone 74 total transplants, and correlated them with clinical indications, ostomy output, and pathologic findings. RESULTS: We found that overall patients with rejection have higher mean levels of stool calprotectin than those without, but because of significant interpatient variability, defining an effective general "cutoff" for the test is difficult. Each patient, in effect, has to act as their own control. Patients experiencing rejection episodes have greater fluctuations in calprotectin levels than those without, suggesting increased "reactivity" within the graft. Our most frequent clinical indicator for biopsy, an increase in ostomy output, had no real relationship to the discovery of rejection. CONCLUSION: Although more frequent prospective sampling could perhaps demonstrate an advantage in early indication of rejection, based on these data, routine stool calprotectin monitoring is not strongly supported.