An Alternative and Up-To-Date Recommendation for a Proper Site for Parathyroid Transplantation: The Omentum.

OBJECTIVES: Various sites have been used for parathyroid allotransplant, such as injection into the forearm, sternocleidomastoid, or deltoid muscles. However, transplant efficiency in these regions varies according to the results reported in the literature and also obtained from our previous studies. Using the omentum "as a natural incubator" for composite tissue-derived cell transplants to increase transplant success is possible. MATERIALS AND METHODS: To examine the efficiency of transplant sites for parathyroid allotransplant, we compared clinical cases from the literature and our experience with 23 cases. The omental transplant process is performed under general anesthesia by laparoscopic intervention. The abdominal cavity is visualized with an endocamera from a 5-mm trocar. With the help of a flexible catheter from another 5-mm trocar, microencapsulated or naked parathyroid cells are deposited on the omentum in approximately 30 mL of isotonic saline. The trocar sites are then sutured, and the surgery is terminated. Recipients were followed for 6 months with examination of biochemical parameters (parathormone, calcium, and phosphorus levels), medication use, and clinical scoring. RESULTS: In the 23 patients who received parathyroid allotransplants over the omentum, 7 recipients did not exhibit any changes according to the scoring system criteria. However, on average, serum calcium and phosphorus levels remained within the healthy reference range. In addition, use of oral medications among patients decreased, indicating successful transplant survival. These results were consistent with a significant decrease in hypocalcemia symptoms among patients. CONCLUSIONS: In the 23 patients, the success rate was 69.5% for the first 6-month period after transplant. Recent developments and large cohorts are needed to demonstrate the higher efficacy of parathyroid allotransplant over the omentum.

The Challenge of Preoperative Panel Reactive Antibody Positivity in Parathyroid Transplantation.

OBJECTIVES: Identifying suitable recipient criteria and matching recipients with appropriate donors are required to increase survival for parathyroid transplant. This study was undertaken to evaluate transplant survival rates while comparing preoperative panel reactive antibody positivity. MATERIALS AND METHODS: The study included 14 hypoparathyroidism patients who presented to our clinic for parathyroid transplant. Preoperative ABO compatibility and negative cross-match tests were prioritized for recipient-donor matching, and panel reactive antibody screening tests were performed. During the 24-month follow-up, we evaluated medication use and serum calcium, phosphorus, and parathormone levels of patients. RESULTS: Preoperative panel reactive antibody positivity was assessed in 3 groups. The HLA class I-positive group (mean fluorescence intensity range, 179-1770) showed decreased medication use and stability in serum calcium levels. The HLA class IIpositive (mean fluorescence intensity range, 85-3959) showed decreased medication use by 25% to 50% and returned to their former prescription doses after 12 months. An opposite pattern was observed in 2 patients with panel reactive antibody positivity for both HLA classes (mean fluorescence intensity range, 462-2289), with 1 patient requiring medication for continuing symptoms and the other patient occasionally taking additional magnesium supplementation, despite decreased medication doses after 12 months. Serum calcium levels remained normal, and parathormone and phosphorus levels were elevated. CONCLUSIONS: Improving patient symptoms and having no requirement for intravenous calcium replacement are priorities, and monitoring serum levels is the next important step. Varied panel reactive antibody positivities and survival rates indicate a requirement, and each HLA class could require a proper limitation for the mean fluorescence intensity. Preoperative mean fluorescence intensity cut-off value should be <900. Higher mean fluorescence intensity values in panel reactive antibody screenings could increase risk of short-term graft survival after parathyroid transplant. Further studies should include immunological risk assessments by individualizing the outcome with donor-specific antibodies.

Effects of chitosan on healing and strength of colonic anastomosis in rats / Efeitos de quitosana na cicatrização e resistência de anastomose colônica em ratos

PURPOSE: To investigate whether chitosan application over colonic anastomosis line, provide reinforcement, and subsequently improve anastomotic healing. METHODS: Forty eight Wistar albino female rats were used and were randomly divided into four groups, 12 rats in each: The control groups (1 and 3) received no further treatment. The experimental groups (2 and 4) received chitosan application over the colonic anastomosis. After sacrifying rats at the end of the experiment (either on day three or on day seven, depending on the group), colonic bursting pressure, a hihydroxyproline level and histopathologic characteristics of the perianastomotic tissue were examined. RESULTS: At three days, chitosan and control groups had similar values for histopathologically. On day seven, chitosan group had significantly higher mean score of collagenization (p=0.007) and a significantly higher bursting pressure (p=0.038). CONCLUSION: Our study emphasizes the positive effect of chitosan in the process of collagenation in colonic anastomosis healing.

OBJETIVO: Investigar se a aplicação de quitosana em anastomose colônica promove resistência à tração e consequentemente a melhora na cicatrização. MÉTODOS: Foram utilizados 48 ratos Wistar fêmeas distribuídos em quatro grupos, 12 ratos em cada. Grupos controle (1 e 3) não receberam tratamento. Grupos experimento (2 e 4) receberam aplicação de quitosana na anastomose colônica. Após eutanásia após 3º ou 7º dias foram examinadas a tensão, o nível de hidroxiprolina e aspectos histopatológicos da anastomose. RESULTADOS: Após três dias os grupos controle e quitosana não apresentaram alterações histopatológicas. No sétimo dia o grupo quitosana apresentou significante elevação do escore de colagenização (p=0,007) e da tensão de ruptura (p=0,038). CONCLUSÃO: A quitosana apresentou bons resultados nos processos de colagenização e cicatrização de anastomose colônica.