Native Spleen Preservation During Visceral Transplantation Inhibits Graft-Versus-Host-Disease Development: Clinical and Experimental Study.

OBJECTIVE: We aimed to assess whether native spleen preservation during visceral transplantation (VT) affects graft-versus-host-disease (GVHD) incidence. SUMMARY BACKGROUND DATA: GVHD is one of the most severe and frequently lethal hematological complications after VT procedures. Because there is no specific treatment for GVHD, it is imperative to develop a strategy to reduce donor lymphocyte engraftment and proliferation. METHODS: Our study included both clinical and experimental data. A total of 108 patients were divided into 3 groups: a native spleen preservation group, a native spleen removal with no donor spleen group, and a donor spleen included (allogeneic spleen) group. We also used an allogeneic VT rat model, in which recipients were divided into 2 groups: a native spleen preservation (+SP) group and a native spleen removal (-S) group. Skin rash appearance, histopathological changes, chimerism, and spleen effects on circulating allogeneic T-cells were assessed. RESULTS: The patients with native spleen preservation showed a lower rate of GVHD ( P <.001) and better survival ( P <.05) than those in the other groups. Skin and histological signs of GVHD were lower in the rats in the +SP group ( P <.05). The donor T-cell frequency in the bloodstream and skin was also significantly reduced when the native spleen was preserved ( P <.01 and P <.0001, respectively). CONCLUSIONS: The clinical and experimental data indicate that recipient spleen preservation protects against GVHD after VT, and donor cell clearance from the bloodstream by spleen macrophages could be the underlying mechanism. Therefore, spleen preservation should be considered in VT procedures, whenever possible.

Experimental Assessment of Intestinal Damage in Controlled Donation After Circulatory Death for Visceral Transplantation.

There is an urgent need to address the shortage of potential multivisceral grafts in order to reduce the average time in waiting list. Since donation after circulatory death (DCD) has been successfully employed for other solid organs, a thorough evaluation of the use of intestinal grafts from DCD is warranted. Here, we have generated a model of Maastricht III DCD in rodents, focusing on the viability of intestinal and multivisceral grafts at five (DCD5) and twenty (DCD20) minutes of cardiac arrest compared to living and brain death donors. DCD groups exhibited time-dependent damage. DCD20 generated substantial intestinal mucosal injury and decreased number of Goblet cells whereas grafts from DCD5 closely resemble those of brain death and living donors groups in terms intestinal morphology, expression of tight junction proteins and number of Paneth and Globet cells. Upon transplantation, intestines from DCD5 showed increased ischemia/reperfusion damage compared to living donor grafts, however mucosal integrity was recovered 48 h after transplantation. No differences in terms of graft rejection, gene expression and absorptive function between DCD5 and living donor were observed at 7 post-transplant days. Collectively, our results highlight DCD as a possible strategy to increase multivisceral donation and transplantation procedures.

Preclinical Study of DCD and Normothermic Perfusion for Visceral Transplantation.

Considering recent clinical and experimental evidence, expectations for using DCD-derived intestines have increased considerably. However, more knowledge about DCD procedure and long-term results after intestinal transplantation (ITx) is needed. We aimed to describe in detail a DCD procedure for ITx using normothermic regional perfusion (NRP) in a preclinical model. Small bowel was obtained from pigs donors after 1 h of NRP and transplanted to the recipients. Graft Intestinal samples were obtained during the procedure and after transplantation. Ischemia-reperfusion injury (Park-Chiu score), graft rejection and transplanted intestines absorptive function were evaluated. Seven of 8 DCD procedures with NRP and ITx were successful (87.5%), with a good graft reperfusion and an excellent recovery of the recipient. The architecture of grafts was well conserved during NRP. After an initial damage of Park-chiu score of 4, all grafts recovered from ischemia-reperfusion, with no or very subtle alterations 2 days after ITx. Most recipients (71.5%) did not show signs of rejection. Only two cases demonstrated histologic signs of mild rejection 7 days after ITx. Interestingly intestinal grafts showed good absorptive capacity. The study's results support the viability of intestinal grafts from DCD using NRP, contributing more evidence for the use of DCD for ITx.

Rhabdomyolysis following Nuss Procedure: A Prospective Study in Children.

INTRODUCTION: Postoperative rhabdomyolysis (RML) has been documented after several surgical procedures in adults. Musculoskeletal remodeling after Nuss procedure for pectus excavatum (PE) could cause RML. We evaluated the incidence of RML after Nuss procedure in children. METHODS: This study was a prospective study from 2018 to 2021. We enrolled all otherwise healthy patients who underwent PE correction with only one bar. Studied variables included demographic and clinical data, duration of surgery, complications, and length of hospitalization. The patients included underwent serial measurements of serum creatine kinase (CK), troponin I, N terminal pro B-type natriuretic peptide (NT-proBNP), serum creatinine, urea, and glomerular filtration rate at 6 and 48 hours postoperatively, and hospital discharge. RESULTS: Forty-six patients met criteria (40 males/6 females), with a mean age of 15.1 ± 1.4 years. Mean duration of surgery was 74 ± 28 minutes, and length of hospitalization was 4.6 ± 1.6 days. RML was diagnosed in 30.4% of patients at 6 hours, 91.3% at 48 hours, and 21.7% at hospital discharge. Mean preoperative CK value was 181.1 ± 141.6 IU/L, and postoperative values were 863.3 ± 302.6 IU/L at 6 hours, 1,675.2 ± 561 IU/L at 48 hours, and 850 ± 683.7 IU/L at hospital discharge, with statistically significant differences (p = 0.001). High-sensitivity troponin I and NT-proBNP levels increased significantly during the postoperative time (p = 0.001). Renal function remained stable (p = 0.55). CONCLUSION: Nuss technique produces RML without kidney injury in healthy patients. This knowledge should be considered for patients at increased risk of developing acute kidney injury and other complications.

Antibody-removal therapies for de novo DSA in pediatric intestinal recipients: Why, when, and how? A single-center experience.

Background: Donor-specific anti-HLA antibodies (DSA) impact negatively on the outcome of intestinal grafts. Although the use of antibody-removal therapies (ART) is becoming more frequent in the last few years, issues regarding their timing and effectiveness remain under discussion. Methods: In the present study, we report our experience with eight ART procedures (based on plasmapheresis, intravenous immunoglobulin, and rituximab) in eight pediatric intestinal and multivisceral transplants with de novo DSA (dnDSA). Results: ART were performed when dnDSA appeared in two contexts: (1) concomitant with rejection (acute or chronic) or (2) without rejection or any other clinical symptom. Complete DSA removal was observed in seven out of eight patients, showing an effectiveness of 88%. In the group treated for dnDSA without clinical symptoms, the success rate was 100%, with complete DSA removal and without rejection afterward. A shorter time between DSA detection and ART performance appeared as a significant factor for the success of the therapy (p = 0.0002). DSA against HLA-A and DQ alleles were the most resistant to ART, whereas anti-DR DSA were the most sensitive. In addition, the 8-year allograft survival rate in recipients undergoing ART was similar to that in those without DSA, being significantly lower in non-treated DSA-positive recipients (p = 0.013). Conclusion: The results confirm the effectiveness of ART in terms of DSA removal and allograft survival and encourage its early use even in the absence of clinical symptoms.

Upside-down kidney placement: An alternative in pediatric renal transplantation.

PURPOSE: "Upside-down" kidney placement has been reported as an acceptable alternative in cases of technical difficulty in kidney transplantation but there are few reports in the pediatric population. The aim of our study is to analyze whether the placement of the upside-down kidney could affect graft outcome or produce more complications. MATERIALS AND METHODS: A retrospective study was conducted of pediatric kidney transplants performed in our center between 2005 and 2017 with at least 6 months' follow-up. Epidemiological and anthropometric data, type of donor (deceased/living), graft position (normal/upside-down), reason for the upside-down placement, early, medium and long-term complications and renal function were analyzed and compared with patients transplanted in the same period with a normal graft placement. RESULTS: From 181 transplants, 167 grafts were placed in a normal position (mean age: 10 y and mean weight: 30 kg) and 14 were placed upside-down (10 y, 37 kg) mainly because of vessel shortness after laparoscopic nephrectomy. Male predominance was observed in both groups. 57% of grafts from the control group and 64% of those from study group came from a living donor. Four vascular and two ureteral re-anastomoses were recorded in the control group and two vascular and one ureteral re-anastomosis in the study group (p > 0.05). In the latter group, no grafts have been lost due to vascular or urological causes and no patients have required dialysis. CONCLUSIONS: When necessary, an upside-down placement for the renal graft is a safe alternative in the pediatric population. LEVEL OF EVIDENCE: Level III.

Neonatal Intrathoracic Gastric Volvulus in Marfan's Syndrome.

We report a 12-day-old male who was admitted with vomiting because of an unusual early complication of Marfan's syndrome (MS): a sliding hiatal hernia. Initial ultrasound showed no stomach at its normal position and the chest X-ray presented an intrathoracic gas bubble with the nasogastric tube inside. An upper gastrointestinal contrast study confirmed the complete herniation of the stomach into the thorax. Via an exploratory laparotomy it was carefully reintroduced into the abdomen, following a hiatal reconstruction. A Thal fundoplication and a gastrostomy were also performed to guarantee its fixation. Although characterized by cardiac/aortic abnormalities, MS should be considered in any infant with hiatal/paraesophageal hernia, which should be repaired early to avoid gastric ischemia/volvulus.