A Novel Cooling Device for Kidney Transplant Surgery.

Background: Prolonged warm ischemia time (WIT) in kidney transplantation is associated with numerous adverse outcomes including delayed graft function and decreased patient and graft survival. Circumventing WIT lies in maintaining renal hypothermia and efficiently performing the vascular anastomosis during this portion of the procedure. Although numerous methods of intra-operative renal cooling have been proposed, most suffer from practical limitations, and none have been widely adopted. Herein we describe a novel device specifically designed to maintain renal hypothermia during kidney transplant surgery.Methods: Aluminum tubing was organized in a serpentine pattern to create a malleable, form-fitting cooling jacket to manipulate renal allografts during transplant surgery. Adult porcine kidneys were used to test the device with 4°C saline as coolant. Kidneys were placed at 24°C; surface and core temperatures were monitored using implanted thermocouples. Anastomosis of porcine kidney vessels to GORE-TEX® vascular grafts in an ex-vivo operative field was performed to assess the functionality of the device.Results: The device maintained surface and core graft temperatures of ≤5°C after 60 minutes of WIT. Furthermore, the device provided hands-free retraction and support for the allograft. We found that ex-vivo anastomosis testing was enhanced by the presence of the cooling jacket.Conclusions: This proof-of-concept study demonstrated that our novel device is a practical tool for renal transplantation and can maintain sufficiently cool graft temperatures to mitigate WIT in an ex-vivo setting. This device is the first of its kind and has the potential to improve kidney transplant outcomes by eliminating WIT during graft implantation.

Prevalence of BK Virus in Renal Transplant at a Single Center: Experience With Our Ureteral Reimplantation Surgical Technique.

OBJECTIVES: BK polyomavirus is one of the main causes of chronic renal failure and ureteral stenosis in kidney transplant recipients, affecting approximately 15% of kidney transplant patients during the first year after transplant. The immunosuppressive treatment used in these recipients allows a reactivation of the virus by allowing infection, which can manifest from viruria, viremia, or nephropathy. The use of ureteral stents in renal transplant to prevent postoperative complications has been associated with an increase in BK polyomavirus nephropathy. Our objective was to describe associations between viruria and viremia and our reimplantation surgical technique and ureteral stenting. MATERIALS AND METHODS: We conducted a retrospective review of 184 transplant recipients who were seen at our center between January 2013 and December 2016. To define possible risk factors from analysis of different variables, we categorized patients into 3 groups: patients who did not present with either viremia or viruria caused by BK virus, patients who presented with viremia, and patients who presented with viruria. RESULTS: We found that 127 transplant recipients (69%) presented with neither BK viruria nor BK viremia, 11 recipients (6%) presented with BK viremia, and 46 recipients (25%) presented with BK viruria. No patient in the study had BK polyomavirus nephropathy. CONCLUSIONS: Our type of ureteral stenting has a low rate of BK viruria and BK viremia compared with other studies. In addition, with our technique, the ureteral stent removal procedure does not require an invasive endoscopic procedure, thereby avoiding the consequent economic and assistance inconvenience typically associated with an endoscopic procedure.

Comparison of Pulmonary Gas Exchange During Kidney Transplantation: Second-Generation Laryngeal Mask Airway vs Endotracheal Tube.

INTRODUCTION: We evaluated whether second-generation laryngeal mask airway (LMA) could provide an adequate pulmonary gas exchange during prolonged abdominal surgery compared to endotracheal tube (ETT) using propensity score matching. METHODS: Of the 257 recipients who underwent living donor kidney transplantation (LDKT), the LMA group and ETT group were matched: 87 of 101 recipients who inserted second-generation LMA were matched with 87 of 156 recipients who inserted ETT. Arterial partial pressure of carbon dioxide (PaCO2) and ratio of arterial partial pressure of oxygen to fractional inspired oxygen (PFR) and intraoperative ventilator parameters were compared between the 2 groups. In addition, we compared incidences of postoperative pulmonary and nonpulmonary complications including hoarseness, vocal cord palsy, nausea, vomiting, arrhythmia, and delirium between the 2 groups. RESULTS: Median anesthesia time was 357 minutes. PaCO2 and PFR were comparable between the 2 groups and did not show group and time interaction. Ventilator parameters during surgery were comparable, and incidences of both postoperative pulmonary and nonpulmonary complications were also comparable between the 2 groups. CONCLUSION: Second-generation LMA could provide an adequate pulmonary gas exchange compared with ETT during LDKT. In terms of pulmonary gas exchange, second-generation LMA could be considered as a suitable alternative to ETT during prolonged abdominal surgery.

Robotic Renal Autotransplantation: A Feasibility Study in a Porcine Model.

We investigated the feasibility of robotic renal autotransplantation (RAT) in a porcine model to reduce invasiveness of RAT. Five pigs underwent robotic RAT using the da Vinci® robotic system. A robotic left nephrectomy was performed in all cases. Robotic RAT was performed on the left side in all but one case. Four ports were used. In 3 cases, the kidney was taken out through the GelPort® and irrigated on ice with Ringer's solution. In 2 cases, a complete intracorporeal robotic RAT was performed. An end-to-side anastomosis was performed between the renal vein and the external iliac vein and between the renal artery and the external iliac artery. Ureteroneocystostomy was also performed in 2 cases. All cases were performed robotically without open conversion. The median (IQR) console time was 3.1 (0.7) h, and the operative time was 3.8 (1.1) h. The estimated blood loss was 30 (0) ml. The warm ischemia time was 4.0 (0.2) min, and the cold ischemia time was 97 (17) min. Intracorporeal transarterial hypothermic renal perfusion was feasible in the 2 complete intracorporeal robotic RAT cases by using a perfusion catheter through a laparoscopic port. Robotic RAT has the potential to be a new minimally invasive substitute for conventional open surgery.

Reduction of Warm Ischemia Using a Thermal Barrier Bag in Kidney Transplantation: Study in a Pig Model.

BACKGROUND: With recent advances in surgical technologies, minimally invasive endoscopic and robot-assisted surgical procedures have been introduced. However, prolonged warm ischemic time of the kidneys remains a concern after the organ is removed from a donor and during transplantation into a recipient. We developed a Thermal Barrier Bag (TBB) to prevent warm ischemia during transplantation. To confirm the effectiveness of the TBB, adenosine triphosphate (ATP) activity in the kidney was measured during an ex vivo warming test. An ischemia model porcine kidney was also used as the donor kidney and placed into the TBB; thereafter, the change in temperature at the time of transplantation was examined. MAIN FINDINGS: The purse-like design of the TBB efficiently suppressed heat conduction. A simulation was conducted that allowed the calculation of organ heat transfer condition. In the ex vivo experiment, temperature increases were suppressed in the group whose kidneys were placed in the TBB (30 minutes after transplantation: with TBB = 30°C, without TBB = 35°C). ATP measurements showed that the residual rate was substantially higher in the TBB group (P = .056). Moreover, a temperature suppression effect was demonstrated during the renal transplantation experiment (30 minutes after transplantation: with TBB = 27°C, without TBB = 31°C). CONCLUSION: The ex vivo warming experiment demonstrated that use of TBB slows down the rate of ATP decay in fresh kidneys. In addition, when an ischemic model porcine kidney was placed into the TBB and the temperature change at the time of transplantation was measured, an in vivo temperature-suppressing effect was observed.

Twenty-four-hour normothermic perfusion of discarded human kidneys with urine recirculation.

Transportable normothermic kidney perfusion for 24 hours or longer could enable viability assessment of marginal grafts, increased organ use, and improved transplant logistics. Eleven clinically declined kidneys were perfused normothermically, with 6 being from donors after brain death (median cold ischemia time 33 ± 36.9 hours) and 5 being from donors after circulatory death (36.2 ± 38.3 hours). Three kidneys were perfused using Ringer's lactate to replace excreted urine volume, and 8 kidneys were perfused using urine recirculation to maintain perfusate volume without fluid replenishment. In all cases, normothermic perfusion either maintained or slightly improved the histopathologically assessed tubular condition, and there was effective urine production in kidneys from both donors after brain death and donors after circulatory death (2367 ± 1798 mL vs 744.4 ± 198.4 mL, respectively; P = .44). Biomarkers, neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 were successfully detected and quantified in the perfusate. All kidneys with urine recirculation were readily perfused for 24 hours (n = 8) and exhibited physiological perfusate sodium levels (140.7 ± 1.2 mmol/L), while kidneys without urine recirculation (n = 3) achieved a reduced normothermic perfusion time of 7.7 ± 1.5 hours and significantly higher perfusate sodium levels (159.6 ± 4.63 mmol/:, P < .01). Normothermic machine perfusion of human kidneys for 24 hours appears to be feasible, and urine recirculation was found to facilitate the maintenance of perfusate volume and homeostasis.

Development of a robot-assisted kidney transplantation programme from deceased donors in a referral academic centre: technical nuances and preliminary results.

OBJECTIVE: To report the development of the first robot-assisted kidney transplantation (RAKT) programme from deceased donors, examining technical feasibility and early perioperative and functional outcomes at a referral academic centre. PATIENTS AND METHODS: A RAKT programme was developed in 2016 at our institution following structured modular training. Specific inclusion/exclusion criteria for both living and deceased donors were set. Data from patients undergoing RAKT from January 2017 to April 2018 were prospectively collected in an a priori developed web-based data set. RAKT followed the principles of the Vattikuti Urology Institute-Medanta technique, with specific technical modifications based on clinical recipient characteristics, as well as surgeon's skills and preference during the learning curve. Technical feasibility of RAKT from deceased donors and evaluation of perioperative and early functional outcomes were the main study endpoints. RESULTS: In all, 17 RAKTs were performed during the study period. Of these, six were from living donors and 11 were from deceased donors. All RAKTs were successfully completed without need of conversion. The median (interquartile range [IQR]) console time was 190 (160-220) min and the median (IQR) estimated blood loss was 120 (110-140) mL. The median times to complete venous, arterial and uretero-vesical anastomoses were 21, 22 and 21 min, respectively. The median (IQR) length of stay was 8 (6-12) days. At a median (IQR) follow-up of 8 (6-11) months, five (30%) complications were recorded. Of these, four (24%) were minor (Clavien-Dindo Grade I-II) and one major (Clavien-Dindo Grade IIIb, requiring graft nephrectomy). Overall, two patients were still on dialysis at last follow-up. A significant improvement in graft function was recorded progressively at all postoperative time points. CONCLUSION: Our preliminary experience outlines that: (i) the development of a RAKT programme is feasible in centres experienced in robotic surgery and open kidney transplantation; (ii) RAKT from deceased donors is feasible from both a technical and logistical perspective; and (iii) RAKT from deceased donors appears to achieve favourable early postoperative and functional outcomes. Larger studies with longer follow-up are needed to confirm these findings and compare the outcomes of RAKT from deceased donors with those from living donors.

Fulminant hepatic failure after simultaneous kidney-pancreas transplantation: a case report / Insuficiência hepática fulminante após transplante simultâneo de rim-pâncreas: um relato de caso

Abstract We describe an unusual case of hyperacute hepatic failure following general anesthesia in a patient receiving a simultaneous kidney-pancreas transplant. Despite an aggressive evaluation of structural, immunological, viral, and toxicological causes, a definitive cause could not be elucidated. The patient required a liver transplant and suffered a protracted hospital course. We discuss the potential causes of fulminant hepatic failure and the perioperative anesthesia management of her subsequent liver transplantation.

Resumo Descrevemos um caso incomum de insuficiência hepática hiperaguda após a anestesia geral em uma paciente que recebeu um transplante simultâneo de rim-pâncreas. Apesar de uma avaliação agressiva das causas estruturais, imunológicas, virais e toxicológicas, uma causa definitiva não pôde ser identificada. A paciente precisou de um transplante de fígado que resultou em prolongamento da internação hospitalar. Discutimos as potenciais causas da insuficiência hepática fulminante e o manejo da anestesia no período perioperatório de seu subsequente transplante de fígado.

Duplicated Ureters in Transplantation-A Single-center, Retrospective Study.

BACKGROUND: Kidney transplantation remains the best therapeutic option for chronic renal failure. The objective of the study was to evaluate the impact of ureteral duplication in donor kidneys on transplantation outcome. METHODS: In this study we performed a retrospective analysis of 75 patients who had undergone renal transplantation. The evaluated parameters included frequency of occurrence and risk of reoperation and graftectomy, mortality, as well as dependency of early and long-term graft function on pyelocaliceal system duplication. RESULTS: Ureteral duplication was associated with more frequent double J stent catheter implantation (P < .05). There was no relationship detected between ureteral duplication, number of operations performed, and risk of graftectomy (P > .05). Early graft function with 2 ureters was similar to that of grafts with a single pyelocaliceal system. The long-term results were also comparable. CONCLUSION: Ureteral duplication should not be considered a contraindication for renal transplantation.

A novel 3D-printed hybrid simulation model for robotic-assisted kidney transplantation (RAKT).

Robotic-assisted kidney transplantation (RAKT) offers key benefits for patients that have been demonstrated in several studies. A barrier to the wider uptake of RAKT is surgical skill acquisition. This is exacerbated by the challenges of modern surgery with reduced surgical training time, patient safety concerns and financial pressures. Simulation is a well-established method of developing surgical skill in a safe and controlled environment away from the patient. We have developed a 3D printed simulation model for the key step of the kidney transplant operation which is the vascular anastomosis. The model is anatomically accurate, based on the CT scans of patients and it incorporates deceased donor vascular tissue. Crucially, it was developed to be used in the robotic operating theatre with the operating robot to enhance its fidelity. It is portable and relatively inexpensive when compared with other forms of simulation such as virtual reality or animal lab training. It thus has the potential of being more accessible as a training tool for the safe acquisition of RAKT specific skills. We demonstrate this model here.

Minimizing the Number of Urological Complications After Kidney Transplant: A Comparative Study of Two Types of External Ureteral Stents.

OBJECTIVES: The aim of this study was to evaluate the effects of 2 types of external ureteral stents on the number of urological complications after kidney transplant. MATERIALS AND METHODS: Data were retrospectively collected from 366 consecutive transplants performed between January 2013 and January 2015 in our hospital, in which an external ureteral stent was placed during surgery and removed after 9 days. Urological complications were defined as urinary leakage or ureteral stenosis requiring percutaneous nephrostomy placement. RESULTS: A total of 197 patients received a straight stent with 2 larger side holes (type A; 8F "Covidien" tube; Covidien, Dublin, Ireland) and 169 patients received a single J stent with 7 smaller side holes (type B; 7F "Teleflex" single J stent; Teleflex Medical, Athlone, Ireland). We found a significantly higher number of percutaneous nephrostomy placements with type A stents, with 34 (17%) versus 16 (9%) in type B (P = .030). Reason for percutaneous nephrostomy placement, occurrence of stent dysfunction, and need for early removal (< 8 days) were equal in both groups (P = .397), whereas incidence of rejection and urinary tract infection were higher in type B stent group. Patient and graft survival did not differ between the groups. CONCLUSIONS: Use of the type B stent was associated with less urological complications compared with the type A stent.

Internal or External Stenting of the Ureterovesical Anastomosis in Renal Transplantation.

BACKGROUND: Stenting of the ureterovesical anastomosis reduces the incidence of urological complications (UCs) after renal transplantation, but there are multiple stenting techniques, and there is no consensus regarding which technique is preferred. The aim of this study was to compare an internal versus an external stenting technique on the incidence of UCs. METHODS: This is a retrospective analysis of 419 deceased donor renal transplantations performed between January 2008 and December 2013. Until 2011, 183 patients received an external stent through the ureterovesical anastomosis placed by suprapubic bladder puncture (SP stent). From 2011, 236 recipients received an internal double-J (JJ) stent. RESULTS: The rate of UC was 3.8% in JJ stents, compared to 9.3% in SP stents (p = 0.021). No difference in surgical ureter revision rate was observed between the groups (2.1 vs. 5.5%; p = 0.068). Urinary tract infection (UTI) rate and graft function were comparable between both groups. CONCLUSIONS: Internal JJ stenting significantly decreased the incidence of UC compared to an external SP stent. There was no difference in surgical ureter revision rate, UTI or graft function.

The Digital Microscopy in Organ Transplantation: Ergonomics of the Tele-Pathological Evaluation of Renal and Liver Grafts.

AIM: Ergonomics of Digital Microscopy (DM) based on virtual slides, on Telemedicine Systems (TS) for Tele-Pathological (TPE) evaluation of the grafts (G) in organ transplantation (OT). MATERIAL AND METHODS: Simulation of DM on TS based TPE by 2 specialists on a total of 238 human Renal Graft (RG) and 172 Liver Graft (LG) tissues digital microscopic images diagnosing inflammatory and neoplastic lesions on four different electronic spaces (ES). RESULTS: DM on TS for TPE in OT is elaborated perfectly on the ES of a Desktop, followed by the ES of the applied Exp.-TS. Tablet and Mobile-Phone ES seem significantly risky for the application of DM in OT (p<.001). CONCLUSION: Integration of DM on TS for TPE is feasible, while ergonomics of post-grafting and pre-transplant decision support and planning depend on the size of the working ES.

A rare complication after renal transplantation: Forgotten stent.

In renal transplantation surgery, double J stents (DJS) are often used to reduce complications, protect the anastomosis between ureter and bladder, provide drainage in ureteral obstructions and enhance healing if there is an ureter injury. Urinary tract infections, hematuria and irritative voiding symptoms are the early complications of DJS. Migration, fragmentation, encrustation and rarely sepsis are among the late complications of DJS. In this report we describe a renal transplantation case whose DJS stent was forgotten because the patient did not attend the regular follow-up and noticed 5 years after surgery.

Minimally invasive renal autotransplantation.

Minimally invasive renal allotransplantation techniques have been recently described; reported benefits include reduced morbidity/complications. These benefits have been successfully adapted for minimally invasive renal autotransplantation, however, in a non-oncological setting. We, here, describe a novel alternative robot-assisted renal autotransplantation technique, utilizing GelPOINT, which by permitting ex vivo graft examination and surgery might allow further broadening of indications for minimally-invasive renal autotransplantation, to include complex oncological renal/ureteral lesions. Future studies are needed to evaluate the utility of these techniques.

Hypothermic machine perfusion of kidneys retrieved from standard and high-risk donors.

Hypothermic machine perfusion (HMP) of kidneys is a long-established alternative to static cold storage and has been suggested to be a better preservation method. Today, as our deceased donor profile continues to change towards higher-risk kidneys of lower quality, we are confronted with the limits of cold storage. Interest in HMP as a preservation technique is on the rise. Furthermore, HMP also creates a window of opportunity during which to assess the viability and quality of the graft before transplantation. The technology might also provide a platform during which the graft could be actively repaired, making it particularly attractive for higher-risk kidneys. We review the current evidence on HMP in kidney transplantation and provide an outlook for the use of the technology in the years to come.

Normothermic machine perfusion of the kidney: better conditioning and repair?

Kidney transplantation is limited by hypothermic preservation techniques. Prolonged periods of cold ischaemia increase the risk of early graft dysfunction and reduce long-term survival. To extend the boundaries of transplantation and utilize kidneys from more marginal donors, improved methods of preservation are required. Normothermic perfusion restores energy levels in the kidney allowing renal function to be restored ex vivo. This has several advantages: cold ischaemic injury can be avoided or minimized, the kidney can be maintained in a stable state allowing close observation and assessment of viability and lastly, it provides the ideal opportunity to add therapies to directly manipulate and improve the condition of the kidney. This review explores the experimental and clinical evidence for ex vivo normothermic perfusion in kidney transplantation and its role in conditioning and repair.

A long-forgotten indwelling single-J stent in a transplant kidney.

Ureteral stent placement is usual after renal transplantation to avoid ureteral obstruction and facilitate reconstruction. However, stent is prone to infection, encrustation, migration, fragmentation, obstruction, and even obstructive nephropathy with a long-indwelling time. Forgotten ureteric stent in renal transplant recipients is scarcely reported. Here, we present a case of long-forgotten indwelling single-J stent for 5 years in a transplant patient.

Forgotten ureteric stents in renal transplant recipients: three case reports.

Ureteric stents are widely used in renal transplantation to minimize the early urological complications. Ureteric stents are removed between two and 12 weeks following trans-plantation, once the vesico-ureteric anastomosis is healed. Ureteric stents are associated with considerable morbidity due to complications such as infection, hematuria, encrustations and migration. Despite the patient having a regular follow-up in the renal transplant clinic, ureteric stents may be overlooked and forgotten. The retained or forgotten ureteric stents may adversely affect renal allograft function and could be potentially life-threatening in immunocompromised transplant recipients with a single transplant kidney. Retrieving these retained ureteric stents could be challenging and may necessitate multimodal urological treatments. We report three cases of forgotten stents in renal transplant recipients for more than four years. These cases emphasize the importance of patient education about the indwelling ureteric stent and possibly providing with a stent card to the patient. Maintaining a stent register, with a possible computer tracking system, is highly recommended to prevent such complications.

Successful endourological management of the 'forgotten' stent in a transplanted kidney.

BACKGROUND: Ureteric stents are used to prevent urological complications like ureteric fistulas and obstruction in kidney transplants. Despite its advantages, complications arising from delayed removal of a double J (DJ) stent include urinary tract infections, stone encrustation, and migration of the DJ stent [Sansalone et al.: Transplant Proc 2005;37:2511-2515]. Encrustation of the stent makes removal difficult and risks injury to the transplanted kidney. CASE PRESENTATION: We report a case of retained DJ stent for 19 years presenting with recurrent urinary tract infections. A radiograph revealed a retained ureteric stent extending from the right iliac fossa transplant kidney to the urinary bladder with multiple foci of large calcification along its length. Two sessions of extracorporeal shockwave lithotripsy along the stent were performed after a percutaneous nephrostomy tube had been placed in the transplanted kidney. Subsequently, the retained DJ stent was removed endoscopically after laser lithotripsy to remnant calcifications. Remnant stone fragments were removed with another session of ureteroscopy and laser lithotripsy. The patient achieved complete stent and stone clearance with a functioning graft. CONCLUSION: This case illustrates that significant stone encrustation of the retained stent in a transplanted kidney can be treated successfully with a combination of endourological techniques.