Mohammad Golriz

Liver stiffness is directly influenced by central venous pressure

BACKGROUND & AIMS Liver stiffness (LS) as measured by transient elastography [Fibroscan] offers a novel non-invasive approach to assess liver cirrhosis. Since Fibroscan seems to be unreliable in patients with congestive heart failure, it remains to be determined whether hemodynamic changes affect LS irrespective of fibrosis. METHODS & RESULTS Using landrace pigs, we studied the direct relationship between the central venous pressure and LS measured by Fibroscan. Clamping of the inferior caval vein increased LS from 3.1 to 27.8kPa while reopening reversed LS within 5min to almost normal values of 5.1kPa. We then studied LS as a function of venous pressure in the isolated pig liver by clamping the upper and lower caval, portal vein and hepatic artery. The stepwise increase of intravenous pressure to 36cm of water column (3.5kPa) linearly and reversibly increased LS to the upper detection limit of 75kPa. We finally measured LS in 10 patients with decompensated congestive heart failure before and after recompensation. Initial LS was elevated in all patients, in 8 of them to a degree that suggested liver cirrhosis (median 40.7kPa). Upon recompensation with a median weight loss of 3.0kg, LS decreased in all 10 patients down to a median LS of 17.8kPa. Inflammation could not account for increased LS since initial liver enzyme counts were only slightly elevated and did not change significantly. CONCLUSION LS is a direct function of central venous pressure which should be considered when assessing the degree of fibrosis.

One life ends, another begins: Management of a brain-dead pregnant mother-A systematic review-

BackgroundAn accident or a catastrophic disease may occasionally lead to brain death (BD) during pregnancy. Management of brain-dead pregnant patients needs to follow special strategies to support the mother in a way that she can deliver a viable and healthy child and, whenever possible, also be an organ donor. This review discusses the management of brain-dead mothers and gives an overview of recommendations concerning the organ supporting therapy.MethodsTo obtain information on brain-dead pregnant women, we performed a systematic review of Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). The collected data included the age of the mother, the cause of brain death, maternal medical complications, gestational age at BD, duration of extended life support, gestational age at delivery, indication of delivery, neonatal outcome, organ donation of the mothers and patient and graft outcome.ResultsIn our search of the literature, we found 30 cases reported between1982 and 2010. A nontraumatic brain injury was the cause of BD in 26 of 30 mothers. The maternal mean age at the time of BD was 26.5 years. The mean gestational age at the time of BD and the mean gestational age at delivery were 22 and 29.5 weeks, respectively. Twelve viable infants were born and survived the neonatal period.ConclusionThe management of a brain-dead pregnant woman requires a multidisciplinary team which should follow available standards, guidelines and recommendations both for a nontraumatic therapy of the fetus and for an organ-preserving treatment of the potential donor.

Hypothermic ante situm Resection in Tumors of the Hepatocaval Confluence

Primary liver malignancies together with metastatic liver tumors are among the most common tumors in human. The best available treatment option for these diseases is surgical resection. One major parameter which had been considered as contraindication for liver resection owing to technical difficulties in achieving tumor-free margins was the involvement of the hepatocaval confluence. To overcome this problem, several techniques including hypothermic in situ, ante situm and ex situ liver resection have been introduced. The common basis for these liver resections is the total vascular exclusion of the liver, and perfusion of the organ by preservation solution under hypothermic conditions. The major indications for the ante situm liver resection are tumors in the liver that are either unresectable or inadequately resectable by conventional surgery because they involve the venous confluence and/or the retrohepatic vena cava, or are in close proximity to them. This technique is a realistic option to achieve surgical cure or substantial gain of life time with quality of life in otherwise unresectable tumors of the liver. Due to fewer anastomoses, the ante situm approach is easier and safer than the ex situ approach, with an acceptable morbidity and mortality rate. Patient selection is of utmost importance to achieve a good outcome. To minimize the postoperative morbidities and mortality, this procedure requires a multidisciplinary approach and should be performed in experienced centers with a high case volume of hepatobiliary surgeries.

A single center experience of combined liver kidney transplantation

With advancements in the operative techniques, patient survival following liver transplantation (LTx) has increased substantially. This has led to the acceleration of pre‐existing kidney disease because of immunosuppressive nephrotoxicity making additional kidney transplantation (KTx) inevitable. On the other hand, in a growing number of patients on the waiting list to receive liver, long waiting time has resulted in adverse effect of decompensated liver on the kidney function. During the last two decades, the transplant community has considered combined liver kidney transplantation (CLKTx) to overcome this problem. The aim of our study is to present an overview of our experience as well as a review of the literature in CLKTx and to discuss the controversy in this regard. All performed CLKTx (n = 22) at our institution as well as all available reported case series focusing on CLKTx are extracted. The references of the manuscripts were cross‐checked to implement further articles into the review. The analyzed parameters include demographic data, indication for LTx and KTx, duration on the waiting list, Model for End‐Stage Liver Disease (MELD) score, Child‐Turcotte‐Pugh (CTP) score, immunosuppressive regimen, post‐transplant complications, graft and patient survival, and cause of death. From 1988 to 2009, a total of 22 CLKTx were performed at our institution. The median age of the patients at the time of CLKTx was 44.8 (range: 4.5–58.3 yr). The indications for LTx were liver cirrhosis, hyperoxaluria type 1, polycystic liver disease, primary or secondary sclerosing cholangitis, malignant hepatic epithelioid hemangioendothelioma, cystinosis, and congenital biliary fibrosis. The KTx indications were end‐stage renal disease of various causes, hyperoxaluria type 1, polycystic kidney disease, and cystinosis. The mean follow‐up duration for CLKTx patients were 4.6 ± 3.5 yr (range: 0.5–12 yr). Overall, the most important encountered complications were sepsis (n = 8), liver failure leading to retransplantation (n = 4), liver rejection (n = 3), and kidney rejection (n = 1). The overall patient survival rate was 80%. Review of the literature showed that from 1984 to 2008, 3536 CLKTx cases were reported. The main indications for CLKTx were oxalosis of both organs, liver cirrhosis and chronic renal failure, polycystic liver and kidney disease, and liver cirrhosis along with hepatorenal syndrome (HRS). The most common encountered complications following CLKTx were infection, bleeding, biliary complications, retransplantation of the liver, acute hepatic artery thrombosis, and retransplantation of the kidney. From the available data regarding the need for post‐operative dialysis (n = 673), a total of 175 recipients (26%) required hemodialysis. During the follow‐up period, 154 episodes of liver rejection (4.3%) and 113 episodes of kidney rejection (3.2%) occurred. The cumulative 1, 2, 3, and 5 yr survival of both organs were 78.2%, 74.4%, 62.4%, and 60.9%, respectively. Additionally, the cumulative 1, 2, 3, and 5 yr patient survival were 84.9%, 52.8%, 45.4%, and 42.6%, respectively. The total number of reported deaths was 181 of 2808 cases (6.4%), from them the cause of death in 99 (55%) cases was sepsis. It can be concluded that there is still no definitive evidence of better graft and patient survival in CLKTx recipients when compared with LTx alone because of the complexity of the exact definition of irreversible kidney function in LTx candidates. Additionally, CLKTx is better to be performed earlier than isolated LTx and KTx leading to the avoidance of deterioration of clinical status, high rate of graft loss, and mortality. Shorter graft ischemia time and more effective immunosuppressive regimens can reduce the incidence of graft malfunctioning in CLKTx patients. Providing a model to reliably determine the need for CLKTx seems necessary. Such a model can be shaped based upon new and precise markers of renal function, and modification of MELD system.

Intestinal transplantation: review of operative techniques.

The improvement of outcomes in intestinal transplantation (ITx) over the last two decades has been made possible through standardization in surgical techniques, improvements in immunosuppressive and induction protocols, and post‐operative patient care. From a surgical technical point of view, all different types of small bowel containing transplants can be categorized into three main prototypes, including isolated small bowel, liver–small bowel, and multivisceral transplantations. In this review, we describe these three main prototypes and discuss the most important technical modifications of each type, as well as donor and recipient procedures, and highlight the more recent operative technical topics of discussion in the literature.

Comparison of the laparoscopic versus open live donor nephrectomy: an overview of surgical complications and outcome

BackgroundKidney transplantation (KTx) is considered to be the treatment of choice for end stage renal disease. One of the most challenging dilemmas in KTx is the shortage of suitable organs. The live donor nephrectomy is considered a unique operation performed on healthy donors, which provides a superior outcome in the recipients.Several surgical techniques have been developed so far to minimize donor postoperative complications as much as possible without compromising the quality of the kidney. The development of a minimally invasive surgery, laparoscopic live donor nephrectomy (LDN), was based on this concept.Materials and MethodsBy searching the pubmed, we reviewed the most evidence based clinical studies specifically randomized clinical trials and meta-analyses to give an overview of the efficacy and safety of LDN versus ODN.ResultsThe advantages of a LDN vs. a conventional open donor nephrectomy (ODN) are a smaller incision, better wound cosmetics, a lower rate of incisional hernia and adhesion, less postoperative pain, shorter hospitalization, and earlier return to work. Some concerns are longer operative and warm ischemic times, long-term learning curve for surgeons, and the risk of more serious complications than during an ODN.ConclusionOverall, the review of literature shows that a LDN provides less postoperative pain, a shorter hospital stay, a shorter period of rehabilitation, and earlier return to normal work and physical activities in comparison to the conventional open flank nephrectomy but is comparable to the mini muscle splitting approach. The complication rate is generally lower in centers accustomed to performing LDNs; however, complications can be life threatening and could impose significant costs to the health system. Weighing the longer operation and warm ischemic time, as well as the risk of more serious complications against the advantages of a LDN mandates a precise indication. The risk-benefit assessment for choosing one procedure should be done meticulously. Even though the short-term graft function in both techniques is comparable, there is a lack of enough long-term outcome analyses. Finally, in any transplant center, the cost of the laparoscopic procedure should be considered.

Using microdialysis for early detection of vascular thrombosis after kidney transplantation in an experimental porcine model

BACKGROUND In kidney transplantation (KTx), vascular thrombosis has a major impact on morbidity and graft survival. The ischaemia, caused by thrombosis, can lead to interstitial metabolite changes. The aim of this experimental study was to create conditions in which the graft would be prone to vascular thrombosis following KTx and then to evaluate the role of microdialysis (MD) for its early detection. METHODS Sixteen randomized pigs in the control group received heparin and immunosuppressive drugs, while the case group received none. Based on histopathological evidence of vascular thrombosis, the case group was subdivided into mildly and severely congested subgroups. Using MD, we evaluated the interstitial concentrations of glucose, lactate to pyruvate ratio, glutamate and glycerol in the transplanted grafts during different phases of KTx. RESULTS Following reperfusion, we noted considerable changes. The severely congested subgroup showed a low and decreasing level of glucose. Only in this group did the lactate to pyruvate ratio continue to increase until the end of monitoring. The glycerol level increased continuously in the entire case group and this increase was most significant in the severely congested subgroup. In all of the study groups, glutamate concentration remained in a low steady state until the end of monitoring. CONCLUSION MD can be an appropriate method for early detection of vascular complications after KTx. Decreasing glucose levels, increased lactate to pyruvate ratio and increased glycerol levels are appropriate indicators for early detection of vascular thromboses following KTx. Particularly, the glycerol level could predict the necessity and urgency of intervention needed to ultimately save the transplanted kidney.

Pig kidney transplantation: an up-to-date guideline.

Background: Swine and human beings have many aspects in common that make swine a well-characterized large animal model for kidney transplantation (KTx). However, pigs have some peculiar anatomical characteristics that standardized techniques must adapt to. The aim of this study was to prepare an up-to-date guideline for porcine KTx. Methods: To achieve this goal, we performed a Medline search using the terminology ‘kidney’ or ‘renal’ and ‘transplantation’ and ‘pig’ or ‘swine’ or ‘porcine’. We found over 1,300 published articles since 1963. Only 13 studies focused on the surgical aspect. Furthermore, we reviewed related books and articles about swine anatomical characteristics and surgery. Finally, our experimental experiences of KTx during the last few decades were added to this collection. Results: Proper hosting, fasting, anesthesia, medical therapy and monitoring can prevent postoperative complications. Explantation with a Carrel patch of the aorta facilitates the implantation and prevents future stenosis. Native nephrectomy makes the follow-up of the implanted organ more precise. KTx in the infrarenal fossa via end-to-side anastomosis to the aorta and inferior vena cava followed by ureteroureterostomy are the recommended options for KTx in pigs compared to other possible methods. Conclusion: Pigs, with respect to their characterizations, constitute one of the best large animal models for KTx. Preoperative preparations are as important as the intra- and postoperative management. Using the most adaptable methods of surgery with respect to the specific anatomical characteristics of pigs can prevent undermining the studies and avoid preventable complications and pitfalls.

The Role of an Interdisciplinary Transplant Team on Living Donation Kidney Transplantation Program

During the last decades, the disparity between the organ supply and the demand for kidney transplantation in Europe has led to consider living donors as a more acceptable option. In the last 7 years, we have established an interdisciplinary supporting transplant team to increase the rate of living donation. After 2001, the new interdisciplinary transplant team consisted of a transplant surgeon, a nephrologist, a pediatrician, a radiologist, a psychologist, a transplant coordinator, and a transplant nurse. We performed a prospective analysis to examine the effect of implementing this team on our living donation program. Demographic data, the annual number of procedures, the duration of waiting, and the cold ischemia time were evaluated among brain-dead and living donors. From January 2002 until December 2008, the number of patients who were annually on the waiting list increased 42% (from 377 to 536 patients). Consequently, the number of the total kidney transplants increased from 81 to 120 with an annual median of 98 cases. By implementing the interdisciplinary transplant team, a significant increase of living kidney donors was observed: from 18 to 42 cases; median = 27). In the last 7 years, a total number of 796 kidney transplants have been performed: 567 from brain-dead and 229 from living donors. In 2001, the waiting list times for recipients who received grafts from brain-dead versus living donors were 1356 versus 615 days respectively. Compared with 2008, the duration on the waiting list decreased significantly for patients receiving a living donor graft, whereas there was a slight increase for the patients in the brain-dead group: brain death versus living donors: 1407 versus 305 days. The interdisciplinary approach has also reduced the cold ischemia time for the living donor recipients: 3 hours and 42 minutes in 2001 versus 2 hours and 50 minutes in 2008. During the last years, by implementing an interdisciplinary transplant team, supporting living donor procedures has produce a gradual increase in the number of kidney transplants from living donors with a remarkable decrease in waiting and cold ischemia times, the latter presumably influencing graft quality.

Models of Short Bowel Syndrome in Pigs: A Technical Review

Background: Short bowel syndrome (SBS) is still a life-threatening disease in both children and adults. Although the therapeutic options are improving, challenges still remain, and to overcome these challenges is a major focus of SBS research today. In order to simulate anatomical and physiological conditions similar to those in humans for research, porcine models of SBS are often used. Various approaches for generating SBS models have been described in the literature. Methods/Results: In this work, we present a review of different types of porcine models of SBS and outline the differences between those models regarding types of animals, surgical procedures, monitoring, and methods of assessment. Conclusion: The aim of this study was to select the most suitable SBS model regarding the purpose of the research.