Do we need animal hands-on courses for transplantation surgery?

BACKGROUND: Transplantation surgery requires many years of training. This study evaluates and presents the results of our recent four-yr animal hands-on courses of transplantation surgery on participants' training. METHODS: Since 2008, five two-d hands-on courses of transplantation surgery were performed on swine models at our department. Sixty-one participants were asked to answer three questionnaires (pre-course, immediate post-course, subsequent post-course). The questions pertained to their past education, expectations, and evaluation of our courses, as well as our course's effectiveness in advancing their surgical abilities. The results were analyzed, compared and are presented herein. RESULTS: On average, 1.8 multiorgan procurements, 2.3 kidney, 1.5 liver, and 0.7 pancreas transplantations were performed by each participant. 41.7% of participants considered their previous practical training only satisfactory; 85% hoped for more opportunities to practice surgery; 73.3% evaluated our courses as very good; and 95.8% believed that our courses had fulfilled their expectations. 66% found the effectiveness of our course in advancing their surgical abilities very good; 30% good, and 4% satisfactory. CONCLUSION: Animal hands-on courses of transplantation surgery are one of the best options to learn and practice different operations and techniques in a near to clinical simulated model. Regular participation in such courses with a focus on practical issues can provide optimal opportunities for trainees with the advantage of direct mentoring and feedback.

Evaluating the effects of extended cold ischemia on interstitial metabolite in grafts in kidney transplantation using microdialysis.

PURPOSE: During kidney transplantation (KTx), the length of cold ischemia time (CIT) and the subsequent changes in energy metabolism may lead to variations in interstitial metabolites. Using microdialysis (MD), we evaluated the effects of a short and long CIT on changes of these metabolites. METHODS: Sixteen pigs were randomized in two identical groups, one with a short CIT and the other one with a long CIT. Using MD in the transplanted grafts, we evaluated the parenchyma concentrations of glucose, lactate, pyruvate, glutamate and glycerol in different stages. RESULTS: We noted that during the warm ischemia time (WIT) and in the early post-reperfusion phase glucose levels increased more significantly in the long CIT group and remained high until the end of monitoring. At the end of CIT and during WIT, the long CIT group had a significantly higher glycerol level, but the level dropped gradually in the late post-reperfusion phase and reached a steady state in both groups. CONCLUSIONS: The extended CIT clearly results in considerably impaired graft metabolism. The high interstitial glucose levels within hours after KTx could be considered as a marker of primary delayed function of the graft. Furthermore, the glycerol value could reflect the extent of graft injury during the ischemia time or in case of acute impairment of graft perfusion.

Hepatic Hemodynamic Changes Following Stepwise Liver Resection.

AIM: Extended liver resection has increased during the last decades. However, hepatic hemodynamic changes after resection and the consequent complications like post hepatectomy liver failure are still a challenging issue. The aim of this study was to systematically evaluate the role of stepwise liver resection on hepatic hemodynamic changes. METHODS: To evaluate this effect we performed 25, 50, and 75 % sequential liver resections in 10 pigs. Before and after each resection, the hepatic artery flow and portal vein flow in relation to the remnant liver volume (RLV) as well as hepatic vascular pressures were measured and compared between the groups. RESULTS: Following sequential liver resection, the hepatic artery flow /100 g decreases and the portal vein flow increases up to 17 and 167 % following extended liver resection (75 %), respectively. Also, during stepwise liver resection, the portal vein pressure increases gradually up to 33 % following extended hepatectomy (75 %). CONCLUSION: Sequential decrease in the RLV decreases the hepatic artery flow /100 g and increases the portal vein flow /100 g and portal vein pressure. As the consequence, the liver goes under more poor-oxygenated blood supply and higher pressure. This may be one of the most important mechanisms of the post hepatectomy liver failure in case of extended liver resection.

Significance of the Extent of Intestinal Resection on the Outcome of a Short-bowel Syndrome in a Porcine Model.

AIM OF THE STUDY: Insufficient data are available to determine the most suitable extent of intestinal resection required to induce short-bowel syndrome (SBS) in pigs. This study aimed to compare the three main SBS-models published. METHODS: A 75%, 90%, or 100% mid-intestinal resection was performed in groups of n = 5 pigs each. Clinical (body weight, stool consistency) and biochemical (serum eletrolytes, citrulline, albumin, prealbumin, and transferrin) parameters were determined daily, functional (D-xylose resorption) and histological (intestinal villus length) parameters were determined after 2 weeks. A t-test and ANOVA were used for statistical analysis. RESULTS: Only in the 100% group, we observed a persistent weight loss (13.6 ± 3.8%) and diarrhea, as well as a decrease in prealbumin-levels (41%) and transferrin levels (33%). Serum electrolytes remained stable in all groups during the observation period. Citrulline stabilized at different levels (100% group 13.9 ± 1.0 µmol/L; 90% group 18.8 ± 1.0 µmol/L; 75% group 26.3 ± 1.4 µmol/L; all p < .05). D-xylose resorption was lowest in the 100%, followed by 90% and 75% group (100% group 32.8 ± 4.9 mg/L; 90% group 50.0 ± 19.6 mg/L; 75% group 57.8 ± 8.8 mg/L; p = .393). Intestinal villus length decreased in all groups (100% group 11.0%; 90% group 14.0%; 75% group 19.1%). CONCLUSIONS: 75% intestinal resection is less suitable as an SBS model, as animals tend to recover remarkably. The 90% model is suitable for longer-term studies, as animals might survive longer due to partial compensation. Due to severe nutritional, biochemical, and physiological derangements, the 100% model can only be used for acute experiments and those immediately followed by small bowel transplantation.

A systematic review and meta-analysis of laparoscopic versus open distal pancreatectomy for benign and malignant lesions of the pancreas: it's time to randomize.

BACKGROUND: Laparoscopic distal pancreatectomy is regarded as a feasible and safe surgical alternative to open distal pancreatectomy for lesions of the pancreatic tail and body. The aim of the present systematic review was to provide recommendations for clinical practice and research on the basis of surgical morbidity, such as pancreas fistula, delayed gastric empting, safety, and clinical significance of laparoscopic versus open distal pancreatectomy for malignant and nonmalignant diseases of the pancreas. METHODS: A systematic literature search (MEDLINE) was performed to identify all types of studies comparing laparoscopic distal pancreatectomy and open distal pancreatectomy. Random effects meta-analyses were calculated after critical appraisal of the included studies and presented as odds ratios or mean differences each with corresponding 95% confidence intervals. RESULTS: A total of 4,148 citations were retrieved initially; available data of 29 observational studies (3,701 patients overall) were included in the meta-analyses. Five systematic reviews on the same topic were found and critically appraised. Meta-analyses showed superiority of laparoscopic distal pancreatectomy in terms of blood loss, time to first oral intake, and hospital stay. All other parameters of operative morbidity and safety showed no difference. Data on oncologic radicality and effectiveness are limited. CONCLUSION: Laparoscopic distal pancreatectomy seems to be a safe and effective alternative to open distal pancreatectomy. No more nonrandomized trials are needed within this context. A large, randomized trial is warranted and should focus on oncologic effectiveness, defined end points, and cost-effectiveness.

Is microdialysis useful for early detection of acute rejection after kidney transplantation?

INTRODUCTION: Acute rejection following kidney transplantation (KTx) is still one of the challenging complications leading to chronic allograft failure. The aim of this study was to investigate the role of microdialysis (MD) in the early detection of acute graft rejection factor following KTx in porcine model. METHODS: Sixteen pigs were randomized after KTx into case (n = 8, without immunosuppressant) and control groups (n = 8, with immunosuppressant). The rejection diagnosis in our groups was confirmed by histopathological evidences as "acute borderline rejection". Using MD, we monitored the interstitial concentrations of glucose, lactate, pyruvate, glutamate and glycerol in the transplanted grafts after reperfusion. RESULTS: In the early post-reperfusion phase the lactate level in our case group was significantly higher comparing to the control group and remained in higher levels until the end of monitoring. The lactate to pyruvate ratio showed a considerable increase in the case group during the post-reperfusion phase. The other metabolites (glucose, glycerol, glutamate) were nearly at the same levels at the end of our monitoring in both study groups. CONCLUSION: The increase in lactate and lactate to pyruvate ratios seems to be an indicator for early detection of acute rejection after KTx. Therefore, MD as a minimally invasive measurement tool may help to identify the need to immunosuppression adjustment in the early KTx phase before the clinical manifestation of the rejection.

Long-Term Follow-Up of Kidney Transplant Recipients With Polycystic Kidney Disease.

OBJECTIVES: Patients with polycystic kidney disease are candidates for kidney transplant. We report the results of our single center study of 250 first transplant recipients with polycystic kidney disease (autosomal dominant [64%], medullary cystic [16%], autosomal recessive [6%], and nonspecified [14%]). MATERIALS AND METHODS: Patient groups were divided and analyzed according to the origin of the graft (deceased donor or living donor). We also analyzed demographic data of donors and recipients, waiting time, duration of dialysis, transfusion, nephrectomy, hospitalization, morbidities, and graft and patient survival. The study was approved by the Ethical Review Committee of the Institute. All of the protocols conformed to the ethical guidelines of the 1975 Helsinki Declaration. RESULTS: The deceased-donor group comprised 79% and the living-donor group comprised 21% of the cases. Nephrectomy was performed on 21% of the recipients. The deceased-donor group showed significantly higher values than the living-donor group regarding rate of hemodialysis (82% vs 68%), duration of dialysis (1571 vs 1002 days), waiting time (1129 vs 33 days), and blood transfusions (45% vs 27%). In deceased-donor versus living-donor transplant recipients, surgical complications included arterial stenosis (1% vs 0%), venous thrombosis (1% vs 0%), urine leakage (0.5% vs 1.9%), ureteral stenosis (0.5% vs 0%), reflux (0% vs 1.9%), lymphocele (11.7% vs 8.1%), and hernia (5.2% vs 8.1%), with no statistically significant differences shown between the groups. The living-donor group had graft and patient survival rates as high as the deceased-donor group. CONCLUSIONS: The low rate of morbidity and excellent survival rates make kidney transplant an excellent option for patients with polycystic kidney disease. Although fear of future appearance of polycystic kidney disease may reduce the rate of related living donors, our study showed that graft and patient survival rates in the living-donor group were as high as in the deceased-donor group.

A systematic review of localization, surgical treatment options, and outcome of insulinoma.

OBJECTIVE: Insulinoma with an incidence of 0.4% is a rare pancreatic tumor. Preserving surgery is the treatment of choice. Exact localization is necessary to plan the appropriate approach. This article gives an overview on localization and surgical strategies for treatment of insulinoma. METHODS: In this systematic review, 114 articles with 6222 cases of insulinoma were reviewed with emphasis on localization techniques and surgical treatment. RESULTS: Insulinoma happens mostly in the fifth decade of life, with a higher incidence in men. They occur mostly sporadic (94%), benign (87%), and single (90%). Insulinomas are mostly smaller than 20 mm (84%). The tumors are distributed almost equally in the pancreas. CONCLUSIONS: Computed tomography is routinely used as first choice preoperatively. Intraoperative inspection, palpation, and sonography were applied with high success rate. Intraoperative sonography is considered as the most reliable technique. Enucleation is the most administered type of surgery (56%). Different types of resection include distal pancreatectomy (32%), Whipple procedure (3%), and subtotal pancreatectomy (<3%). Despite the development of laparoscopy, open approach is the favorite method (90%). The most common surgical complication is fistula. The mortality rate of open approach was higher (4 vs 0%). Despite high cure rate, recurrence of insulinoma occurs in 7% after surgery.

Technical guidelines for porcine liver allo-transplantation: a review of literature.

Experimental animal research has been pivotal in the development of clinical liver transplantation (LTx). Results obtained in these experiments have been applied in clinic and clinical challenges have been scrutinized in animal laboratories. Porcine model is an optimal model in the field of experimental LTx research. Here, we present the various techniques of experimental LTx in the porcine model in detail. Different methods and modifications have been described. The following major steps have been discussed in detail: donor liver preparation, recipient operation including recipient hepatectomy, and reconstruction phase, including the reconstruction of suprahepatic inferior vena cava (SHIVC), portal vein (PV), infrahepatic inferior vena cava (IHIVC), hepatic artery (HA) and bile duct (BD). IHIVC and SHIVC are anastomosed end to end directly or with the use of prosthesis anastomosed side to side. The PV anastomosis is performed end to end between donor and recipient PV, Cuff method or Stump method. Arterialization has been accomplished via carrel patch or donor HA end to end with recipient HA. There are three major methods for reconstruction of BD: end to end or end to side choledochocholedochostomy or choledojejunostomy with Roux-en-Y jejunal loop. Each method has advantages and disadvantages regarding the objectives of the study; the most physiological techniques may be preferred for long-term survival studies, while the faster techniques may be selected for experimentations aiming the direct postoperative phase.