Review Paper on Penetrating Brain Injury: Ethical Quandaries in the Trauma Bay and Beyond.

OBJECTIVE: The aim of this review was to review the ethical and multidisciplinary clinical challenges facing trauma surgeons when resuscitating patients presenting with penetrating brain injury (PBI) and multicavitary trauma. BACKGROUND: While there is a significant gap in the literature on managing PBI in patients presenting with multisystem trauma, recent data demonstrate that resuscitation and prognostic features for such patients remains poorly described, with trauma guidelines out of date in this field. METHODS: We reviewed a combination of recent multidisciplinary evidence-informed guidelines for PBI and coupled this with expert opinion from trauma, neurosurgery, neurocritical care, pediatric and transplant surgery, surgical ethics and importantly our community partners. RESULTS: Traditional prognostic signs utilized in traumatic brain injury may not be applicable to PBI with a multidisciplinary team approach suggested on a case-by-case basis. Even with no role for neurosurgical intervention, neurocritical care, and neurointerventional support may be warranted, in parallel to multicavitary operative intervention. Special considerations should be afforded for pediatric PBI. Ethical considerations center on providing the patient with the best chance of survival. Consideration of organ donation should be considered as part of the continuum of patient, proxy and family-centric support and care. Community input is crucial in guiding decision making or protocol establishment on an institutional level. CONCLUSIONS: Support of the patient after multicavitary PBI can be complex and is best addressed in a multidisciplinary fashion with extensive community involvement.

Normothermic Machine Perfusion of Donor Livers for Transplantation in the United States: A Randomized Controlled Trial.

OBJECTIVE: To compare conventional low-temperature storage of transplant donor livers [static cold storage (SCS)] with storage of the organs at physiological body temperature [normothermic machine perfusion (NMP)]. BACKGROUND: The high success rate of liver transplantation is constrained by the shortage of transplantable organs (eg, waiting list mortality >20% in many centers). NMP maintains the liver in a functioning state to improve preservation quality and enable testing of the organ before transplantation. This is of greatest potential value with organs from brain-dead donor organs (DBD) with risk factors (age and comorbidities), and those from donors declared dead by cardiovascular criteria (donation after circulatory death). METHODS: Three hundred eighty-three donor organs were randomized by 15 US liver transplant centers to undergo NMP (n = 192) or SCS (n = 191). Two hundred sixty-six donor livers proceeded to transplantation (NMP: n = 136; SCS: n = 130). The primary endpoint of the study was "early allograft dysfunction" (EAD), a marker of early posttransplant liver injury and function. RESULTS: The difference in the incidence of EAD did not achieve significance, with 20.6% (NMP) versus 23.7% (SCS). Using exploratory, "as-treated" rather than "intent-to-treat," subgroup analyses, there was a greater effect size in donation after circulatory death donor livers (22.8% NMP vs 44.6% SCS) and in organs in the highest risk quartile by donor risk (19.2% NMP vs 33.3% SCS). The incidence of acute cardiovascular decompensation at organ reperfusion, "postreperfusion syndrome," as a secondary outcome was reduced in the NMP arm (5.9% vs 14.6%). CONCLUSIONS: NMP did not lower EAD, perhaps related to the inclusion of lower-risk liver donors, as higher-risk donor livers seemed to benefit more. The technology is safe in standard organ recovery and seems to have the greatest benefit for marginal donors.

Digital imaging software versus the "eyeball" method in quantifying steatosis in a liver biopsy.

Steatotic livers represent a potentially underutilized resource to increase the donor graft pool; however, 1 barrier to the increased utilization of such grafts is the heterogeneity in the definition and the measurement of macrovesicular steatosis (MaS). Digital imaging software (DIS) may better standardize definitions to study posttransplant outcomes. Using HALO, a DIS, we analyzed 63 liver biopsies, from 3 transplant centers, transplanted between 2016 and 2018, and compared macrovesicular steatosis percentage (%MaS) as estimated by transplant center, donor hospital, and DIS. We also quantified the relationship between DIS characteristics and posttransplant outcomes using log-linear regression for peak aspartate aminotransferase, peak alanine aminotransferase, and total bilirubin on postoperative day 7, as well as logistic regression for early allograft dysfunction. Transplant centers and donor hospitals overestimated %MaS compared with DIS, with better agreement at lower %MaS and less agreement for higher %MaS. No DIS analyzed liver biopsies were calculated to be >20% %MaS; however, 40% of liver biopsies read by transplant center pathologists were read to be >30%. Percent MaS read by HALO was positively associated with peak aspartate aminotransferase (regression coefficient= 1.04 1.08 1.12 , p <0.001), peak alanine aminotransferase (regression coefficient = 1.04 1.08 1.12 , p <0.001), and early allograft dysfunction (OR= 1.10 1.40 1.78 , p =0.006). There was no association between HALO %MaS and total bilirubin on postoperative day 7 (regression coefficient = 0.99 1.01 1.04 , p =0.3). DIS provides reproducible quantification of steatosis that could standardize MaS definitions and identify phenotypes associated with good clinical outcomes to increase the utilization of steatite livers.

hEPCR.hTBM.hCD47.hHO-1 with donor clodronate and DDAVP treatment improves perfusion and function of GalTKO.hCD46 porcine livers perfused with human blood.

INTRODUCTION: Platelet sequestration, inflammation, and inappropriate coagulation cascade activation are prominent in liver xenotransplant models and are associated with poor outcomes. Here, we evaluate a cassette of six additional genetic modifications to reduce anti-pig antibody binding (α-1,3-galactosyl transferase knockout [GalTKO]) and target coagulation dysregulation (human endothelial protein C receptor [hEPRC] and thrombomodulin [hTBM]), complement pathway regulation (human membrane cofactor protein, hCD46), inflammation heme oxygenase 1 [hHO-1]), and a self-recognition receptor (integrin-associated protein [hCD47]), as well as donor pharmacologic treatments designed to blunt these phenomena. METHODS: Livers from GaltKO.hCD46 pigs ("2-gene," n = 3) and GalTKO.hCD46 pigs also transgenic for hEPRC, hTBM, hCD47, and hHO-1 ("6-gene," n = 4) were perfused ex vivo with whole human blood. Six-gene pigs were additionally pretreated with desmopressin (DDAVP) and clodronate liposomes to deplete vWF and kupffer cells, respectively. RESULTS: The average perfusion times increased from 304 (±148) min in the 2-gene group to 856 (±61) min in the 6-gene group (p = .010). The average heparin administration was decreased from 8837 U/h in the 2-gene to 1354 U/h in the 6-gene group (p = .047). Platelet sequestration tended to be delayed in the 6-gene group (p = .070), while thromboxane B2 (TXB2, a platelet activation marker) levels were lower over the first hour (p = .044) (401 ± 124 vs. 2048 ± 712 at 60 min). Thrombin production as measured by F1+2 levels tended to be lower in the 6-gene group (p = .058). CONCLUSIONS: The combination of the hEPCR.hTBM.hCD47.hHO-1 cassette along with donor pig DDAVP and clodronate liposome pretreatment was associated with prolonged function of xenoperfused livers, reduced coagulation pathway perturbations, and decreased TXB2 elaboration, and reflects significant progress to modulate liver xenograft injury in a pig to human model.

Which cava anastomotic techniques are optimal regarding immediate and short-term outcomes after liver transplantation: A systematic review of the literature and expert panel recommendations.

BACKGROUND: It has long been debated whether cava anastomosis should be performed with the piggyback technique or cava replacement, with or without veno-venous bypass (VVB), with or without temporary portocaval shunt (PCS) in the setting of liver transplantation. OBJECTIVES: To identify whether different cava anastomotic techniques and other maneuvers benefit the recipient regarding short-term outcomes and to provide international expert panel recommendations. DATA SOURCES: Ovid MEDLINE, Embase, Scopus, Google Scholar, and Cochrane Central. METHODS: A systematic review following PRISMA guidelines and recommendations using the GRADE approach derived from an international expert panel (CRD42021240979). RESULTS: Of 3205 records screened, 307 publications underwent full-text assessment for eligibility and 47 were included in qualitative synthesis. Four studies were randomized control trials. Eighteen studies were comparative. The remaining 25 were single-center retrospective noncomparative studies. CONCLUSION: Based on existing data and expert opinion, the panel cannot recommend one cava reconstruction technique over another, rather the surgical approach should be based on surgeon preference and center dependent, with special consideration toward patient circumstances (Quality of evidence: Low | Grade of Recommendation: Strong). The panel recommends against routine use of vevo-venous bypass (Quality of evidence: Very Low | Grade of Recommendation: Strong) and against the routine use of temporary porto-caval shunt (Quality of evidence: Very Low | Grade of Recommendation: Strong).

The demise of islet allotransplantation in the United States: A call for an urgent regulatory update.

Islet allotransplantation in the United States (US) is facing an imminent demise. Despite nearly three decades of progress in the field, an archaic regulatory framework has stymied US clinical practice. Current regulations do not reflect the state-of-the-art in clinical or technical practices. In the US, islets are considered biologic drugs and "more than minimally manipulated" human cell and tissue products (HCT/Ps). In contrast, across the world, human islets are appropriately defined as "minimally manipulated tissue" and not regulated as a drug, which has led to islet allotransplantation (allo-ITx) becoming a standard-of-care procedure for selected patients with type 1 diabetes mellitus. This regulatory distinction impedes patient access to islets for transplantation in the US. As a result only 11 patients underwent allo-ITx in the US between 2016 and 2019, and all as investigational procedures in the settings of a clinical trials. Herein, we describe the current regulations pertaining to islet transplantation in the United States. We explore the progress which has been made in the field and demonstrate why the regulatory framework must be updated to both better reflect our current clinical practice and to deal with upcoming challenges. We propose specific updates to current regulations which are required for the renaissance of ethical, safe, effective, and affordable allo-ITx in the United States.

Successful Implementation of Unmanned Aircraft Use for Delivery of a Human Organ for Transplantation.

OBJECTIVE: To understand and overcome the challenges associated with moving life-urgent payloads using unmanned aircraft. BACKGROUND DATA: Organ transportation has not been substantially innovated in the last 60 years. Unmanned aircraft systems (UAS; ie, drones) have the potential to reduce system inefficiencies and improve access to transplantation. We sought to determine if UASs could successfully be integrated into the current system of organ delivery. METHODS: A multi-disciplinary team was convened to design and build an unmanned aircraft to autonomously carry a human organ. A kidney transplant recipient was enrolled to receive a drone-shipped kidney. RESULTS: A uniquely designed organ drone was built. The aircraft was flown 44 times (total of 7.38 hours). Three experimental missions were then flown in Baltimore City over 2.8 miles. For mission #1, no payload was carried. In mission #2, a payload of ice, saline, and blood tubes (3.8 kg, 8.4 lbs) was flown. In mission #3, a human kidney for transplant (4.4 kg, 9.7 lbs) was successfully flown by a UAS. The organ was transplanted into a 44-year-old female with a history of hypertensive nephrosclerosis and anuria on dialysis for 8 years. Between postoperative days (POD) 1 and 4, urine increased from 1.0 L to 3.6 L. Creatinine decreased starting on POD 3, to an inpatient nadir of 6.9 mg/dL. The patient was discharged on POD 4. CONCLUSIONS: Here, we completed the first successful delivery of a human organ using unmanned aircraft. This study brought together multidisciplinary resources to develop, build, and test the first organ drone system, through which we performed the first transplant of a drone transported kidney. These innovations could inform not just transplantation, but other areas of medicine requiring life-saving payload delivery as well.

COVID-19 in hospitalized liver transplant recipients: An early systematic review and meta-analysis.

Adverse clinical outcomes related to SARS-CoV-2 infection among liver transplant (LTx) recipients remain undefined. We performed a meta-analysis to determine the pooled prevalence of outcomes among hospitalized LTx recipients with COVID-19. A database search of literature published between December 1, 2019, and November 20, 2020, was performed per PRISMA guidelines. Twelve studies comprising 517 hospitalized LTx recipients with COVID-19 were analyzed. Common presenting symptoms were fever (71%), cough (62%), dyspnea (48%), and diarrhea (28%). Approximately 77% (95% CI, 61%-93%) of LTx recipients had a history of liver cirrhosis. The most prevalent comorbidities were hypertension (55%), diabetes (45%), and cardiac disease (21%). In-hospital mortality was 20% (95% CI, 13%-28%) and rose to 41% (95% CI, 19%-63%) (P < 0.00) with ICU admission. Additional subgroup analysis demonstrated a higher mortality risk in the elderly (>60-65 years) (OR 4.26; 95% CI, 2.14-8.49). There was no correlation in respect to sex or time since transplant. In summary, LTx recipients with COVID-19 had a high prevalence of dyspnea and gastrointestinal symptoms. In-hospital mortality was comparable to non-transplant populations with similar comorbidities but appeared to be less than what is reported elsewhere for cirrhotic patients (26%-40%). Importantly, the observed high case fatality in the elderly could be due to age-associated comorbidities.

Radiation therapy combined with intracerebral convection-enhanced delivery of cisplatin or carboplatin for treatment of the F98 rat glioma.

BACKGROUND: The purpose of this review is to summarize our own experimental studies carried out over a 13-year period of time using the F98 rat glioma as model for high grade gliomas. We evaluated a binary chemo-radiotherapeutic modality that combines either cisplatin (CDDP) or carboplatin, administered intracerebrally (i.c.) by means of convection-enhanced delivery (CED) or osmotic pumps, in combination with either synchrotron or conventional X-irradiation. METHODS: F98 glioma cells were implanted stereotactically into the brains of syngeneic Fischer rats. Approximately 14 days later, either CDDP or carboplatin was administered i.c. by CED, followed 24 h later by radiotherapy using either a synchrotron or, subsequently, megavoltage linear accelerators (LINAC). RESULTS: CDDP was administered at a dose of 3 µg in 5 µL, followed 24 h later with an irradiation dose of 15 Gy or carboplatin at a dose of 20 µg in 10 µL, followed 24 h later with 3 fractions of 8 Gy each, at the source at the European Synchrotron Radiation Facility (ESRF). This resulted in a median survival time (MeST) > 180 days with 33% long term survivors (LTS) for CDDP and a MeST > 60 days with 8 to 22% LTS, for carboplatin. Subsequently it became apparent that comparable survival data could be obtained with megavoltage X-irradiation using a LINAC source. The best survival data were obtained with a dose of 72 µg of carboplatin administered by means of Alzet® osmotic pumps over 7 days. This resulted in a MeST of > 180 days, with 55% LTS. Histopathologic examination of all the brains of the surviving rats revealed no residual tumor cells or evidence of significant radiation related effects. CONCLUSIONS: The results obtained using this combination therapy has, to the best of our knowledge, yielded the most promising survival data ever reported using the F98 glioma model.

Financial incentives versus standard of care to improve patient compliance with live kidney donor follow-up: protocol for a multi-center, parallel-group randomized controlled trial.

BACKGROUND: Live kidney donors (LKDs) account for nearly a third of kidney transplants in the United States. While donor nephrectomy poses minimal post-surgical risk, LKDs face an elevated adjusted risk of developing chronic diseases such as hypertension, diabetes, and end-stage renal disease. Routine screening presents an opportunity for the early detection and management of chronic conditions. Transplant hospital reporting requirements mandate the submission of laboratory and clinical data at 6-months, 1-year, and 2-years after kidney donation, but less than 50% of hospitals are able to comply. Strategies to increase patient engagement in follow-up efforts while minimizing administrative burden are needed. We seek to evaluate the effectiveness of using small financial incentives to promote patient compliance with LKD follow-up. METHODS/DESIGN: We are conducting a two-arm randomized controlled trial (RCT) of patients who undergo live donor nephrectomy at The Johns Hopkins Hospital Comprehensive Transplant Center (MDJH) and the University of Maryland Medical Center Transplant Center (MDUM). Eligible donors will be recruited in-person at their first post-surgical clinic visit or over the phone. We will use block randomization to assign LKDs to the intervention ($25 gift card at each follow-up visit) or control arm (current standard of care). Follow-up compliance will be tracked over time. The primary outcome will be complete (all components addressed) and timely (60 days before or after expected visit date), submission of LKD follow-up data at required 6-month, 1-year, and 2-year time points. The secondary outcome will be transplant hospital-level compliance with federal reporting requirements at each visit. Rates will be compared between the two arms following the intention-to-treat principle. DISCUSSION: Small financial incentivization might increase patient compliance in the context of LKD follow-up, without placing undue administrative burden on transplant providers. The findings of this RCT will inform potential center- and national-level initiatives to provide all LKDs with small financial incentives to promote engagement with post-donation monitoring efforts. TRIAL REGISTRATION: ClinicalTrials.gov number: NCT03090646 Date of registration: March 2, 2017 Sponsors: Johns Hopkins University, University of Maryland Medical Center Funding: The Living Legacy Foundation of Maryland.

Extracorporeal membrane oxygenation support following liver transplantation-A case series.

BACKGROUND: Postoperative severe cardiopulmonary failure carries a high rate of mortality. Extracorporeal membrane oxygenation (ECMO) can be used as a salvage therapy when conventional therapies fail. METHODS: We retrospectively reviewed our experience with ECMO support in the early postoperative period after liver transplant between September 2011 and May 2016. RESULTS: Out of 537 liver transplants performed at our institution, seven patients required ECMO support with a median age of 52 and a median MELD score of 28. Veno-venous ECMO was used in four patients with severe respiratory failure while the rest required veno-arterial ECMO for circulatory failure. The median time from transplant to cannulation was 3 days with a median duration of ECMO support of 7 days. All patients except one were successfully decannulated. The median hospital length of stay was 58 days with an in-hospital mortality of 28.6%. CONCLUSION: Extracorporeal membrane oxygenation can be considered a viable rescue therapy in the setting of severe postoperative cardiopulmonary failure. Extracorporeal membrane oxygenation therapy was successful in saving patients who were otherwise unsalvageable.

Alemtuzumab induction and belatacept maintenance in marginal pathology renal allografts.

We performed a prospective, 12-month, single-center, nonrandomized, open-label pilot study to investigate the use of belatacept therapy combined with alemtuzumab induction in renal allografts with preexisting pathology, as these kidneys may be more susceptible to additional toxicity when exposed to calcineurin inhibitors posttransplant. Nineteen belatacept recipients were matched retrospectively to a cohort of tacrolimus recipients on the basis of preimplantation pathology. The estimated glomerular filtration rate was not significantly different between belatacept and tacrolimus recipients at either 3 or 12 months posttransplant (59 vs 45, P = 0.1 and 56 vs 48 mL/min/1.72/m2 , P = 0.3). Biopsy-proven acute rejection rates at 12 months were 26% in belatacept recipients and 16% in tacrolimus recipients (P = 0.7). Graft survival at 1 year was 89% in both groups. Alemtuzumab induction combined with either calcineurin inhibitor or costimulatory blockade therapies resulted in similar acceptable one-year outcomes in kidneys with preexisting pathologic changes. Longer-term follow-up may be necessary to identify preferential strategies to improve outcomes of kidneys at a higher risk for poor function (ClinicalTrials.gov-NCT01496417).

Endovascular Reconstruction of the Hepatic Arterial System for the Management of Mycotic Pseudoaneurysm in a Liver Transplant Patient.

BACKGROUND: Hepatic artery pseudoaneurysm is a rare but very morbid complication after liver transplant. Treatment options include ligation or endovascular embolization, followed by revascularization. We describe a new endovascular approach by stent exclusion in a high-risk patient. RESULTS: A 62-year-old male who received a second liver transplant after failed allograft presented with hemobilia and was diagnosed with a hepatic artery pseudoaneurysm in the setting of infection. Given his hostile abdomen, an endovascular approach was sought. We excluded the mycotic pseudoaneurysm with multiple covered stent grafts extending from the common hepatic artery to the right and left hepatic arteries. He was discharged with long-term antibiotics. On his 6-month follow-up visit, his stent was patent and hepatic function was stable. CONCLUSIONS: Endovascular stent-graft placement for management of hepatic artery pseudoaneurysm after liver transplant should be considered as a lower morbidity alternative to surgical repair, even in the setting of infection.

Synthetic liver function is detectable in transgenic porcine livers perfused with human blood.

In addition to immune barriers, molecular incompatibilities between species are predicted to limit pig liver survival in primate xenotransplantation models. Assessment and measurement of synthetic function of genetically modified porcine livers after ex vivo perfusion with human blood have not previously been described. Eight porcine livers from α1,3-galactosyl transferase knockout and human membrane cofactor (GalTKO.hCD46), six livers from GalTKO.hCD46 and N-glycolylneuraminic acid knockout (GalTKO.hCD46.Neu5GcKO), and six livers from GalTKO.hCD46 with humanized decay-accelerating factor (hCD55), endothelial protein C receptor (hEPCR), tissue factor pathway inhibitor (hTFPI), and integrin-associated protein (hCD47) (GalTKO.hCD46.hCD55.hEPCR.hTFPI.hCD47) pigs were perfused with human blood under physiologic conditions. Timed blood samples were tested for liver enzymes and for pig-specific albumin production via Western blot. Porcine albumin levels increased with time in all experiments. By densitometry, GalTKO.hCD46.Neu5GcKO livers had the highest albumin levels, measured both as total produced, and when controlled for perfusion duration, compared to GalTKO.hCD46 (P = .068) and GalTKO.hCD46.hCD55.hEPCR.hTFPI.hCD47 livers (P = .04). Porcine livers perfused with human blood demonstrated the synthetic ability to produce albumin in all cases. GalTKO.hCD46.Neu5GcKO pig livers demonstrated the most robust albumin production. This suggests that the Neu5GcKO phenotype provides a protective effect on the graft due to decreased human antibody recognition and graft injury.

Robotic-assisted single-port donor nephrectomy using the da Vinci single-site platform.

BACKGROUND: Although single-port donor nephrectomy offers improved cosmetic outcomes, technical challenges have limited its application to selected centers. Our center has performed over 400 single-port donor nephrectomies. The da Vinci single-site robotic platform was utilized in an effort to overcome the steric, visualization, ergonomic, and other technical limitations associated with the single-port approach. MATERIALS AND METHODS: Food and Drug Administration device exemption was obtained. Selection criteria for kidney donation included body mass index <35, left kidney donors, and ≤2 renal arteries. After colonic mobilization using standard single-port techniques, the robotic approach was utilized for ureteral complex and hilar dissection. RESULTS: Three cases were performed using the robotic single-site platform. Average total operative time was 262 ±â€¯42 min including 82 ±â€¯16 min of robotic use. Docking time took 20 ±â€¯10 min. Blood loss averaged 77 ±â€¯64 mL. No intraoperative complications occurred, and all procedures were completed with our standard laparoscopic single-port approach. CONCLUSIONS: This is the first clinical experience of robotic-assisted donor nephrectomy utilizing the da Vinci single-site platform. Our experience supported the safety of this approach but found that the technology added cost and complexity without tangible benefit. Development of articulating instruments, energy, and stapling devices will be necessary for increased application of robotic single-site surgery for donor nephrectomy.

Diabetic nephropathy after kidney transplantation in patients with pretransplantation type II diabetes: A retrospective case series study from a high-volume center in the United States.

BACKGROUND: Patients with type II diabetes mellitus (DM) undergoing renal transplantation are at risk of diabetic nephropathy (DN) in the transplanted kidney. The true risk of developing post-transplantation DN is unknown, and post-transplantation DN is poorly characterized in the literature. METHODS: The biopsy database at the University of Maryland Medical Center was queried for kidney transplant biopsies which demonstrated evidence of DN. The time from transplantation to biopsy-proven DN (time to diagnosis, TTD) was calculated and analyzed in the context of demographics, serum creatinine, and onset of diabetes. By extrapolating the total number of patients who developed DN in the last 2 years, we estimated the recurrence rate of DN. RESULTS: Sixty patients whose renal biopsies met criteria were identified. The mean age was 56.6 (±1.58) years, and the mean creatinine level at time of biopsy was 1.65 (±0.12) mg/dL. Simultaneous pathological diagnoses were frequent on kidney biopsy; rejection was present at variable rates: classes I, IIA, IIB, and III were 5.0%, 66.7%, 18.4%, and 10%, respectively. The mean TTD was 1456 (±206) days. TTD was significantly shorter for patients receiving a cadaveric vs living donor renal transplant (1118 ± 184 vs 2470 ± 547 days, P = 0.004). Older patients (r = 0.378, P = 0.003) and patients with higher serum creatinine (r = 0.282, P = 0.029) had shorter TTDs. Extrapolations showed that 74.7% of patients would be free of DN 10 years after renal transplantation. CONCLUSIONS: Diabetic nephropathy occurs after transplantation, and this appears to be due to both donor and recipient-derived factors. Encouragingly, our estimates suggest that as many as 75% of patients may be free of DN at 10 years following kidney transplantation.

Minimally invasive donor nephrectomy: current state of the art.

BACKGROUND: The concept of a minimally invasive live donor nephrectomy developed over 20 years ago. Surgeons gained expertise with the laparoscopic technique and utilized multiple variations that are now utilized in transplant centers throughout the world. Recent modifications include laparoendoscopic single-site and robotic approaches that have been adopted by an additional smaller set of programs. PURPOSE: Review was performed of the following eight different surgical approaches to a "minimally invasive" live donor nephrectomy: laparoscopic (LDN), hand-assisted laparoscopic (HALDN), retroperitoneoscopic (RLDN), hand-assisted retroperitoneoscopic (HARS), single-port laparoscopic (LESS), robotic-assisted laparoscopic (RALDN), mini open, and natural orifice transluminal endoscopic (NOTES). The techniques are described and summaries of available outcomes and complications are presented. CONCLUSIONS: Traditional surgical techniques of open donor nephrectomy have transitioned to minimally invasive techniques. With adoption of these techniques as the preferred approach, several variations have and continue to evolve. The current minimally invasive donor nephrectomy techniques share low complication rates and excellent outcomes.

Advances in liver xenotransplantation.

PURPOSE OF REVIEW: This review highlights advances in liver xenotransplantation, focusing on immunologic barriers and mechanisms underlying graft failure and recipient demise, and discussion of recent in-vivo results. RECENT FINDINGS: Pig to primate models of liver xenotransplantation have been plagued by thrombocytopenia, anemia, and coagulopathy. It is now known that platelet sequestration is mediated by liver sinusoidal endothelial cells and Kupffer cells in part by asialoglycoprotein receptor 1-driven mechanisms. Xenoantigens, specifically N-glycolylneuraminic acid, play a role in graft injury as well as red blood cell consumption. Finally incompatibilities between coagulation cascade molecules contribute to lethal coagulopathy, but can be counteracted with genetic modifications and coagulation factor supplementation. Survival has markedly increased with this strategy. SUMMARY: An increased understanding of the cellular mechanisms responsible for failure of in-vivo pig to primate liver xenotransplant models has led to improved outcomes, and this recent success supports initial clinical application.

Molecular Adsorbent Recirculating System Effectively Replaces Hepatic Function in Severe Acute Liver Failure.

BACKGROUND DATA: Patients with severe acute liver failure (ALF) have extreme physiologic dysfunction and often die if transplantation is not immediately available. Patients may be supported with MARS (Baxter International Inc., Deerfield, IL) until transplantation or spontaneous recovery occurs. We present the largest series in the United States of MARS therapy as temporary hepatic replacement for ALF. METHODS: MARS was used to support patients with severe liver trauma (SLT), in ALF patients as a bridge to transplantation (BTT), and as definitive therapy for toxic ingestion or idiopathic liver failure (DT) in a level 1 trauma center and large transplant center. Patient demographics, etiology of ALF, and laboratory values were recorded. Endpoints were patient survival ± liver transplant and/or recovery of liver function. RESULTS: Twenty-seven patients with severe ALF received MARS therapy. Five patients with SLT had a 60% survival with recovery of liver and renal function. Thirteen patients received MARS as a BTT, of which 9 were transplanted with a 1-year survival of 78% (program overall survival 85% at 1 year). All 4 who were not transplanted expired. Nine patients with ALF from toxic ingestion received MARS as DT with liver recovery and survival in 67%. MARS therapy resulted in significant improvement in liver function, coagulation, incidence of encephalopathy, and creatinine. CONCLUSIONS: MARS therapy successfully replaced hepatic function in ALF allowing time for spontaneous recovery or transplantation. Spontaneous recovery was remarkably common if support can be sustained.