[A retrospective analysis of functional and oncologic outcomes following surgical treatment of patients with pT1/pT2 renal cell carcinoma at a tertiary referral centre]

INTRODUCTION

In patients with localised renal cell carcinoma, the only curative treatment option is surgical tumour excision. The aim of this study was to evaluate peri- and postoperative outcomes as well as oncologic and functional long-term results following surgical treatment of patients with renal cell carcinoma (pT1/pT2) at a tertiary referral centre.

PATIENTS AND METHODS

This retrospective study included a total of 758 patients with localised renal cell carcinoma (pT1 /pT2), who underwent radical (RN) or partial (PN) nephrectomy between 01/2008 and 10/2014. Pre-, peri- and postoperative parameters were recorded. Oncologic and functional long-term data were retrieved through questionnaires and structured telephone interviews.

RESULTS

Laparoscopic RN or PN resulted in less blood loss and lower peri- and postoperative complication rates compared to open procedures. Regarding short- and long-term renal function, a higher increase in serum creatinine levels was detected after RN. No difference was noted in health status and quality of life. Median follow-up was 36 months. A total of 10.4 % of patients died during follow-up. 4.7 % and 8.4 % developed a relapse or metastatic disease. No difference was found between laparoscopic and open RN/PNs in terms of oncologic long-term results.

DISCUSSION

In conclusion, all surgical techniques evaluated in this study provided good oncologic and functional short-/long-term outcomes.

Staging lymphadenectomy in patients with localized high risk prostate cancer: comparison of the laparoendoscopic single site (LESS) technique with conventional multiport laparoscopy

BACKGROUND

In patients with localized high-risk prostate cancer awaiting radiation therapy, pelvic lymphadenectomy (PL) is a reliable minimally invasive staging procedure. We compared outcomes after laparoendoscopic single site PL (LESSPL) with those after conventional multiport laparoscopic PL (MLPL).

METHODS

A retrospective case-control study was carried out at the authors' center. For LESSPL the reusable X-Cone single port was combined with straight and prebent laparoscopic instruments and an additional 3 mm needlescopic grasper. MLPL was performed via four trocars of different sizes using standard laparoscopic instruments.

RESULTS

Patients who underwent either LESSPL (n = 20) or MLPL (n = 97) between January 2008 and July 2013, were included in the study. Demographic data were comparable between groups. Patients in the LESSPL group tended to be older and had a significantly higher ASA-score. The mean operating time was 172.4 ± 34.1 min for LESSPL and 116.6 ± 40.1 min for MLPL (P < .001). During LESSPL, no conversion to MLPL was necessary. An average of 12 lymph nodes per patient was retrieved, with no significant difference between study groups. Postoperative pain scores were similar between groups. The hospital stay was 2.3 ± 0.7 days after LESSPL and 3.1 ± 1.2 days after MLPL (P = .01). Two days postoperatively, significantly more patients after LESSPL than after MLPL recovered their normal physical activity (P < .001). Six months postoperatively, no complications were registered in the LESSPL group and cosmetic results were excellent.

CONCLUSIONS

In the present study, shorter hospitalization and quicker postoperative recovery were major benefits of LESSPL over MLPL. In patients with localized prostate cancer, staging LESS pelvic lymphadenectomy may be a safe alternative to conventional multiport laparoscopy.

Volume matters: CT-based renal cortex volume measurement in the evaluation of living kidney donors

Currently, no international standard for the pre-transplant evaluation of living donor renal function exists. Following a standardized questionnaire on current practice in all Eurotransplant (ET) centers, we compared a new CT-based technique to measure renal cortex volume with our standard of DTPA-clearance combined with MAG3-scintigraphy (DTPA × MAG3) and with creatinine-based methods in 167 consecutive living kidney donors. Most ET centers use creatinine-clearance (64%) to measure total renal function and radioistopic methods (82%) to assess split renal function. Before transplantation, CT-measured total cortex volume (r = 0.67; P < 0.001) and estimated GFR using the Cockcroft-Gault formula [eGFR(CG)] (r = 0.55; P < 0.001) showed the strongest correlation with DTPA-clearance. In contrast, the correlation between DTPA-clearance and creatinine clearance was weak (r = 0.21; P = 0.02). A strong correlation was observed between CT-measured split cortex volume and MAG3-measured split renal function (r = 0.93; P < 0.001). A strong correlation was also found between pre-transplant split renal function assessed by eGFR(CG) together with cortex volume measurement and post-transplant eGFR(CG) of both, the donor (r = 0.83; P < 0.001) and the recipient (r = 0.75; P < 0.001). In conclusion CT-based assessment of renal cortex volume bears the potential to substitute existing methods to assess pre-transplant living donor split renal function.

Long-term outcomes of living donor kidney transplants in pediatric recipients following laparoscopic vs. open donor nephrectomy

We compared long-term outcomes of LDKT in pediatric recipients following either laparoscopic (LDN) or ODN. In our retrospective single-center study, we compared 38 pediatric LDKT recipients of a laparoscopically procured kidney with a historic ODN group comprising 17 pediatric recipients. In our center, the first pure laparoscopic non-hand-assisted LDN for a pediatric LDKT recipient was performed in June 2001. Demographic data of donors and recipients were comparable between groups. Mean follow-up was 64 months in the LDN group and 137 months in the ODN group. Patient survival was comparable between groups. Graft survival at one and five yr was 97% (LDN) vs. 94% (ODN) and 91% (LDN) vs. 88% (ODN; p = n.s.), respectively. Serum creatinine at one and five yr was 1.16 ± 0.47 mg/dL (LDN) vs. 1.02 ± 0.38 mg/dL (ODN) and 1.38 ± 0.5 mg/dL (LDN) vs. 1.20 ± 0.41 mg/dL (ODN), respectively. The type and frequency of surgical complications did not differ between groups. DGF and acute rejection rates were similar between groups. In the ODN group, a higher proportion of right donor kidneys was used. In the ODN group, all kidneys had singular arteries, whereas in the LDN group five kidneys had multiple arteries. Arterial multiplicity was associated with a higher incidence of DGF. In our experience, LDN does not compromise long-term graft outcomes in pediatric LDKT recipients. Arterial multiplicity of the donor kidney may be a risk factor for impaired early graft function in the pediatric population.

Successful repair of post-transplant mycotic aneurysm of iliac artery with renal graft preservation: a case report

OBJECTIVE

To describe the successful repair of a post-transplant iliac artery aneurysm with renal graft preservation.

METHODS

An aneurysm was detected in an asymptomatic 47-year-old male recipient on routine Doppler ultrasonography that involved the right external iliac artery and the distal portion of the renal artery. Aneurysm resection was performed immediately after diagnosis 3 months after transplantation. A polytetrafluorethylene tube graft was used for reconstruction of the right external iliac artery. Reconstruction of the renal artery required interposition of a vena saphena graft between the proximal portion of the renal artery and the polytetrafluorethylene tube.

RESULTS

The total warm ischemia time used for aneurysm repair and renal transplant revascularization was 90 minutes. The postoperative Doppler ultrasound scan showed homogeneous graft perfusion. Pathologic and microbiologic examination of the resected aneurysm revealed Candida albicans arteritis. The center in which the contralateral donor kidney was transplanted had previously reported Candida albicans contamination of the preservation solution. The recipient of the contralateral kidney lost his graft owing to bleeding complications. Information on this incident was acquired by our center only after aneurysm repair. Postoperatively, our recipient was given systemic antifungal therapy. At 6 months, the serum creatinine level was 1.7 mg/dL.

CONCLUSION

Although a high-risk procedure, repair of a mycotic aneurysm with renal graft preservation is feasible. Routine microbiologic screening of the preservation solution might help to detect and treat donor-transmitted infections in renal transplant recipients.

Impact of surgeon experience on complication rates and functional outcomes of 484 deceased donor renal transplants: a single-centre retrospective study

OBJECTIVE

To determine how postoperative and functional outcomes after deceased donor renal transplantation (DDRT) are related to surgeon experience.

PATIENTS AND METHODS

The outcomes of 484 adult DDRT performed by 13 urological surgeons were retrospectively reviewed. After completion of a staged renal transplant training programme under supervision of an attending urological transplant surgeon, the 13 surgeons were either assigned to the inexperienced group (n = 8) or the experienced group (n = 5). Surgeons in the experienced group had performed more than 30 unsupervised DDRT in a standard fashion with routine ureteric stenting. Between 1988 and 2005, inexperienced surgeons performed 152 DDRT, whereas experienced surgeons performed 332 DDRT.

RESULTS

Patient and graft survival at 2 hyears were 98% and 94.7%, respectively. Early graft loss in five recipients was unrelated to surgeon experience. Delayed graft function occurred in 29% of cases and median 1-year serum-creatinine was 1.48 mg/dL, with no difference between surgeon groups. Postoperative bleeding and lymphocele formation were the most frequent surgical complications, with an equal distribution between groups. Ureteric complications had a significantly higher incidence among inexperienced surgeons (6.6% versus 2.7%; P = 0.04).

CONCLUSION

We conclude that DDRT as performed by inexperienced urological renal transplant surgeons has both acceptable short- and long-term outcomes.

Extracorporeal shock wave lithotripsy (ESWL) of a renal calculus in a liver transplant recipient: report of a severe complication--a case report

INTRODUCTION

Extracorporeal shock wave lithotripsy (ESWL) has evolved as a standard treatment modality for calculi of the upper urinary tract. Noninvasive ESWL shows rare life-threatening complications. Herein we have reported the case of a liver transplant recipient who developed severe renal hemorrhage after ESWL of a renal calculus. Transfusion of erythrocytes and platelets led to anaphylactic shock with acute renal failure requiring intensive care. The patient fully recovered shortly thereafter and was discharged home with a residual left kidney stone measuring 8 mm.

CASE PRESENTATION

A 55-year-old man with a single left kidney underwent ESWL due to symptomatic left nephrolithiasis. He had undergone successful liver transplantation 11 years earlier. At the time of ESWL his liver functions were normal and his serum creatinine level was 1.3 mg/dL. Two weeks before the treatment a double pigtail ureteral stent was inserted because of a symptomatic left hydronephrosis. Several hours after ESWL treatment the patient complained of left-sided flank pain. An ultrasound revealed a large subcapsular hematoma of the left kidney, which was confirmed using abdominal computed tomography (CT). With the patient being hemodynamically stable, we opted for conservative management. Despite postinterventional complications, the patient made a fast recovery.

CONCLUSION

ESWL is a noninvasive, safe, and efficient method to treat renal calculi. Patients who are at risk for hemorrhage should undergo close postinterventional monitoring, including red blood cell count and renal ultrasound.

Intraoperative assessment of kidney allograft perfusion by laser-assisted indocyanine green fluorescence videography

BACKGROUND

Kidney allograft function crucially depends on the quality of organ perfusion. Duplex sonography, however, frequently reveals hypoperfused segments that remained undetectable to visual inspection intraoperatively. To date, no imaging system supplementing the surgeon's experience has achieved clinical acceptance. The present work examines whether laser-assisted indocyanine green (ICG) fluorescence-videography can be used as a safe and sensitive technique for the intraoperative assessment of renal allograft perfusion.

METHODS

Intraoperative assessment of organ perfusion by laser-assisted ICG fluorescence videography (IC-VIEW) was performed in 10 consecutive de novo renal transplantations. The IC-VIEW system allows the visualization of graft perfusion by the fluorescein dye ICG that emits infrared light after exposure to laser light.

RESULTS

Perfusion measurements were successful in all 10 transplant recipients. Fluorescence videography produced brilliant, sharply contrasted images of the organs, allowing the detection of even small perfusion deficits. Remarkably, this technique detected 1 large perfusion defect that had remained imperceptible to visual inspection. Repositioning of the graft led to a homogeneous overall perfusion. There were no complications with the ICG injection or the imaging device.

CONCLUSION

Laser-assisted ICG fluorescence videography is a feasible and safe technique for the intraoperative assessment of renal allograft perfusion.

Inhibition of 20-HETE synthesis and action protects the kidney from ischemia/reperfusion injury

20-Hydroxyeicosatetraenoic acid (20-HETE) production is increased in ischemic kidney tissue and may contribute to ischemia/reperfusion (I/R) injury by mediating vasoconstriction and inflammation. To test this hypothesis, uninephrectomized male Lewis rats were exposed to warm ischemia following pretreatment with either an inhibitor of 20-HETE synthesis (HET0016), an antagonist (20-hydroxyeicosa-6(Z),15(Z)-dienoic acid), an agonist (20-hydroxyeicosa-5(Z),14(Z)-dienoic acid), or vehicle via the renal artery and the kidneys were examined 2 days after reperfusion. Pretreatment with either the inhibitor or the antagonist attenuated I/R-induced renal dysfunction as shown by improved creatinine clearance and decreased plasma urea levels, compared to controls. The inhibitor and antagonist also markedly reduced tubular lesion scores, inflammatory cell infiltration, and tubular epithelial cell apoptosis. Administering the antagonist accelerated the recovery of medullary perfusion, as well as renal medullary and cortical re-oxygenation, during the early reperfusion phase. In contrast, the agonist did not improve renal injury and reversed the beneficial effect of the inhibitor. Thus, 20-HETE generation and its action mediated kidney injury due to I/R. Whether or not these effects are clinically important will need to be tested in appropriate human studies.

[Incarcerated hernia after laparoscopic drainage of a lymphocele]

Laparoscopic lymphocele drainage is considered the gold standard for the treatment of lymphoceles after kidney transplantation. We report on a female patient who developed a symptomatic posttransplant lymphocele. After laparoscopic lymphocele drainage the patient presented with acute pain in the left lower abdomen. A CT scan showed a hernia into the peritoneal window. This is a rare but potentially severe complication after intraperitoneal lymphocele drainage. CT imaging and swift reoperation with enlargement of the peritoneal window are critical to avoid serious complications. To avoid bowel incarceration, the peritoneal window should be as large as possible.

De novo Renal Transplantation after Kaposi Sarcoma: Favorable Outcome in a Patient Receiving Sirolimus and Mycophenolate-Based Immunosuppression

Immunosuppressive treatment increases the risk of infection and malignancy in organ transplant recipients. We report on a 42-year-old male renal transplant recipient who lost his first graft after reduction of immunosuppressive treatment due to Kaposi sarcoma and who successfully underwent a second renal transplant 10 years later. The patient's current treatment consists of low-dose prednisone, and the two antiproliferative immunosuppressants mycophenolate mofetil and rapamycin. 4.5 years after his second transplant, the serum creatinine is 1 mg/dl and the patient has no signs of recurrent disease.

Outcomes of transplanting deceased-donor kidneys between elderly donors and recipients

Rate of acceptance of deceased-donor kidneys decreases with donor age despite the growing number of aged transplant candidates on the waiting list. In the Eurotransplant Senior Program, HLA-unmatched kidneys from deceased donors aged > or = 65 yr are transplanted regionally into recipients aged > or = 65 yr. Because we have become more willing to accept kidneys from donors aged > or = 75 yr than previous years, we performed a retrospective analysis of this subgroup. Kidneys were accepted from donors aged > or = 75 yr provided a normal creatinine on admission to the hospital, a Cockcroft-Gault creatinine clearance > 80 ml/min, and an absence of comorbidities. We compared outcomes of kidneys from donors aged > or = 75 yr with both younger-donor kidneys transplanted in the Eurotransplant Senior Program and with younger-donor HLA-matched kidneys transplanted into recipients > or = 60 yr. There were no differences in 5-yr graft and patient survival or rate of delayed graft function between groups. Graft function, measured by creatinine and creatinine clearance, differed without pattern at only three of 12 time points during 5 yr of follow-up. In conclusion, our data suggest that kidneys from deceased donors aged > or = 75 yr can be transplanted safely into recipients aged > or = 65 yr if similar donor criteria and local allocation practices are used.

Glutamine donor pretreatment in rat kidney transplants with severe preservation reperfusion injury

BACKGROUND

Glutamine (GLN) has been shown to confer cytoprotection by enhancing endogenous heat shock protein (HSP) expression. We hypothesized that GLN donor pretreatment protects rat renal grafts against severe preservation reperfusion injury (PRI).

MATERIALS AND METHODS

GLN (0.75 g/kg) or saline was administered i.p. to male donor rats 24 h and 6 h before donor nephrectomy. Kidneys (n = 6/group) were cold-stored in UW solution for 40 h and transplanted into bilaterally nephrectomized syngeneic recipients. Grafts were removed after 24 h. Renal HSP 70 expression was determined by Western blotting. Graft function was assessed by serum creatinine. Renal cross sections were microscopically examined for acute tubular necrosis, apoptosis, tubular proliferation, and macrophage infiltration.

RESULTS

GLN donor pretreatment significantly increased intragraft HSP 70 expression. Serum creatinine was not different between groups: 2.6 +/- 0.2 mg/dL (saline) versus 2.7 +/- 0.5 mg/dL (GLN). Both treatment groups showed severe tubular damage with significantly less papillary necrosis in the GLN group (P < 0.05). GLN significantly reduced the number of apoptotic tubular cells in the cortex, medulla, and papilla (P < 0.001 versus saline). Postinjury tubular proliferation, measured by PCNA antigen expression, and intragraft macrophage infiltration was not influenced by GLN.

CONCLUSIONS

In rat renal grafts suffering severe PRI pharmacological preconditioning with GLN attenuates early structural damage, especially tubular cell apoptosis. Stimulation of renal HSP 70 expression could be an important mechanism of GLN-induced cytoprotection. Our findings may have implications for the treatment of delayed graft function in recipients of marginal donor kidneys.

Living donor kidney transplant recipients and clinical trials: participation profiles and impact on post-transplant care

Many transplant physicians believe that transplant candidates who enroll in clinical trials may have better outcomes than those who do not enroll. We examined a 7-year cohort (1997-2003) of adult primary, non-HLA identical, living donor kidney transplant (LDKT) recipients to determine whether demographic characteristics predisposed to enrollment and whether participation affected posttransplant care intensity and/or allograft function. Overall, 146 of 512 (28.5%) LDKT recipients enrolled in clinical trials. LDKT recipients who were male and those who lived <100 miles from our transplant center were significantly more likely to participate. During the first post-transplant year, study patients (SPs) had more clinic visits (p < 0.0001) and more allograft biopsies (p = 0.024) compared to nonstudy patients (NSPs), but comparable numbers of hospital readmissions and allograft ultrasounds. SPs and NSPs did not differ in 1-year creatinine clearance, delta creatinine or rejection incidence. Overall graft and patient survival were comparable. We conclude that clinical trial participants were disproportionately male, had increased intensity of post-transplant care but comparable outcomes to nonparticipants.

End stage polycystic kidney disease: indications and timing of native nephrectomy relative to kidney transplantation

PURPOSE

We evaluated the indications for and outcome of pre-transplant, concomitant and post-transplant native nephrectomy in patients with end stage polycystic kidney disease (PCKD).

MATERIALS AND METHODS

The records of 32 patients were retrospectively reviewed using the electronic database at our institution.

RESULTS

Between January 1992 and December 2002, 171 patients with end stage PCKD received a kidney transplant at University of California-San Francisco. A total of 32 patients (18.7%) underwent pre-transplant (7, group 1), concomitant (16, group 2) or post-transplant (9, group 3) native nephrectomy. Of these patients 25 underwent bilateral nephrectomy. Median followup was 18 months. Indications for nephrectomy were hematuria, a renal mass and chronic pain in group 1, lack of space in group 2 and urinary tract infection in group 3. Mean operative time +/- SEM was 231 +/- 14, 370 +/- 24 and 208 +/- 14 minutes in groups 1 to 3, respectively (p = 0.001). Mean intraoperative blood loss was 533 +/- 105, 573 +/- 155 and 522 +/- 181 ml in groups 1 to 3, respectively (p not significant). Two group 2 patients required blood transfusions. Postoperative complications requiring surgical intervention included wound dehiscence in group 1 and abdominal bleeding in group 3. Mean hospital stay was comparable among groups 1 to 3 at 7 +/- 0.7, 8.6 +/- 1.2 and 6.3 +/- 0.6 days, respectively (p not significant). At 3 months mean serum creatinine was not significantly different between groups 2 and 3 at 1.3 +/- 0.1 and 1.5 +/- 0.2 mg/dl, respectively.

CONCLUSIONS

Unilateral or bilateral nephrectomy for PCKD at transplantation is safe in terms of postoperative patient morbidity and graft function. We perform concomitant native nephrectomy when indicated, preferably in recipients of living donor kidney transplants.

Ureteral Complications in the Renal Transplant Recipient after Laparoscopic Living Donor Nephrectomy

OBJECTIVES

We report on ureteral and surgical complications in our first 110 consecutive recipients of kidneys procured with laparoscopic living donor nephrectomy (LLDN).

METHODS

The records of all living donor transplants with LLDN performed between February 1999 and December 2004, including 10 pediatric transplants, were reviewed retrospectively. Three urologists performed LLDN using a pure laparoscopic non-hand-assisted transperitoneal technique. Kidney transplantation was performed in a standard fashion. For ureteroneocystostomy, the intravesical Politano-Leadbetter (P-L) technique was used.

RESULTS

Two-year patient and graft survival was 99% and 98%, respectively. Serum creatinine at 12 months was 1.36+/-0.1mg/dl in adult and 0.99+/-0.23 mg/dl in pediatric recipients. Nineteen right donor kidneys were transplanted into adult recipients. Surgical complications included three symptomatic lymphoceles, one peritransplant haematoma and one kinking of a lower pole artery. All five (4.5%) ureteral complications occurred in adult recipients with a mean age of 33.2+/-2.8 years. The incidence of ureteral complications was not clustered around the early phase of our LLDN experience. Of the three (2.7%) patients diagnosed with ureteral obstruction, two required ureteral reimplantation, and one was managed conservatively. Another two patients (1.8%) with a urinary leak received a double J stent and a cystostomy catheter for 3 and 5 months, respectively. Of the five patients with a ureteral complication, three had received a donor kidney with more than one renal artery.

CONCLUSIONS

LLDN combined with the intravesical (P-L) ureteral implantation technique provides excellent graft outcomes with low recipient morbidity. Renal artery multiplicity may increase the risk of ureteral complications.

Effect of mycophenolate mofetil on rat kidney grafts with prolonged cold preservation

The impact of mycophenolate mofetil (MMF) on initial renal transplant function is not well characterized. We tested how MMF may modulate graft function and survival in a syngeneic rat kidney transplantation model after prolonged cold preservation. Donor kidneys were preserved in University of Wisconsin for either 24 or 39 h prior to transplantation into nephrectomized rats. Recipients received MMF (20 mg/kg/day) or vehicle. Mycophenolic acid (MPA) blood concentrations were measured by high-performance liquid chromatography. The inflammatory response, tubular epithelial proliferation, and histologic damage 3 days post-transplantation were assessed microscopically. In the 24 h cold storage (c.s.) group serum-creatinine was measured. In the 39 h c.s. group 1-week recipient survival was determined. After 24 h of c.s., recipient survival was 100%. The number of T-cell infiltrates was low and not influenced by MMF, whereas renal ED1+ cell infiltration was significantly suppressed by MMF. Tubular cell proliferation was enhanced by MMF. Serum-creatinine levels and renal histology were comparable between MMF and vehicle-treated animals. In the 39 h c.s. group, recipient survival was 20% in MMF-treated vs 90% in vehicle-treated animals (P=0.001). MMF effectively suppressed inflammatory cell infiltration and inhibited tubular cell proliferation. MMF-induced structural damage was most striking in the renal papilla. In rat kidney grafts with moderate preservation injury (24 h c.s.), MMF, given at an immunosuppressive dose, showed predominantly antiinflammatory effects without compromising graft function. In grafts with severe preservation injury (39 h c.s.), MMF caused irreversible structural damage and inhibited tubular cell regeneration resulting in renal failure.

[Ten years of laparoscopic living kidney donation. From an extravagant to a routine procedure]

Ten years ago the first laparoscopic living donor nephrectomy (LDN) was performed. Today, LDN is a routine operation in many US-American transplantation centers and an increasing number of centers in Europe are practicing LDN. In this article the different aspects of LDN for donor, kidney, recipient and operating surgeon are evaluated. We performed a literature research concerning LDN and the different aspects. Our own experience, as the largest LDN center in Germany, is part of the evaluation. Laparoscopic extraction of a kidney from a living donor is as safe for the donor as the open approach. At the same time, LDN offers multiple advantages like reduced pain and shorter convalescence. For the donated kidney and the recipient no disadvantages occur from the laparoscopic technique, as long as special intra- and perioperative demands are met. For the operating surgeon multiple developments have expanded the technical armentarium. LDN is safe for donor, recipient and kidney. Central issue of an optimal LDN is sufficient experience with laparoscopic urological techniques.

Urologische Betreuung von Patienten vor und nach Nierentransplantation

Patients with end-stage renal disease awaiting kidney transplantation require regular urological evaluation. The urologist's main task is early diagnosis and treatment of genitourinary malignancies and evaluation of the lower urinary tract. Furthermore, urologists are often confronted with the question of whether or not to perform pretransplant urological surgery, i.e., native nephrectomy for polycystic kidney disease. Urological care after kidney transplantation involves diagnosis and treatment of ureteral complications, malignancies, lower urinary tract symptoms, and last but not least erectile dysfunction, which has a prevalence of 20-50% among kidney transplant recipients. For the evaluation and follow-up of the living kidney donor, international guidelines have been developed in recent years to also help the urologist to perform a correct evaluation and follow-up of the kidney donor.

H-NMR-based metabolic signatures of mild and severe ischemia/reperfusion injury in rat kidney transplants

BACKGROUND

Severe ischemia/reperfusion (IR) injury is a risk factor for delayed graft function. Delayed graft function remains difficult to predict, and it currently relies primarily on serum creatinine (SCr), urine output, and occasionally on graft biopsy. (1)H-NMR (nuclear magnetic resonance spectroscopy) based metabolomics was used to establish IR-specific metabolic markers in both blood and kidney tissue. These markers were compared to SCr and graft histology.

METHODS

Male Lewis rats were used for kidney transplantation. Two cold ischemia (CI) groups (24- and 42-hour) and two transplantation groups [after 24 (TX24) and after 42 hours (TX42) of CI] were compared to a control group. Whole blood and kidney tissue were collected for further analysis.

RESULTS

SCr levels taken 24 hours after transplantation were 1.6 +/- 0.12 mg/dL (TX24) and 2.1 +/- 0.5 mg/dL (TX42), (P= n.s.). Histology samples revealed mild injury in the TX24 group and severe injury in the TX42 group. A significantly decreased level of polyunsaturated fatty acids (PUFA) and elevated levels of allantoin, a marker of oxidative stress, was found in the renal tissue. In the blood, both trimethylamine-N-oxide (TMAO), a marker of renal medullary injury, and allantoin were significantly increased. Allantoin levels were low in both the control and CI groups. Levels were significantly increased after reperfusion (control 0.02 +/- 0.03 micromol/mL, TX24 1.13 +/- 0.22, and TX42 1.89 +/- 0.38, P < 0.001), and correlated with cold ischemia time (r= 0.96) and TMAO (r= 0.94).

CONCLUSION

The (1)H-NMR metabolic profiles of both the mild and severe IR groups revealed significant changes consistent with graft histology, while the SCr did not.

Ischemic preconditioning improves rat kidney graft function after severe ischemia/reperfusion injury

Ischemic preconditioning (IP) has been shown to ameliorate renal ischemia reperfusion injury. Using a rat kidney transplantation model we determined if IP improves graft function after prolonged cold storage.

MATERIALS AND METHODS

Syngeneic rat kidneys were divided into two groups. Prior to 42 hours of cold storage in UW and transplantation, one group (n = 10) received IP (15 minutes of warm ischemia/10 minutes of reperfusion), whereas another group (n = 10) received no treatment. Early graft function and 1-week recipient survival were assessed.

RESULTS

Recipient survival was not significantly different between groups [70% (IP) vs 40% (non-IP); P = .28]. IP treatment led to a quicker recovery of renal function. On PODs 3 and 6, serum creatinine levels in the IP group were significantly lower compared with the untreated group. In conclusion, one cycle of IP (15/10) accelerates recovery of renal graft function after severe ischemia reperfusion injury. This simple treatment modality may improve outcomes of renal transplants with prolonged cold storage.

Increased Rejection in Living Unrelated versus Living Related Kidney Transplants does not Affect Short-Term Function and Survival

BACKGROUND

At our institution, increased kidney donation from unrelated donors accounts for a steady rise in live donor kidney transplantation rates. We compared outcomes of living related (LRT) versus living unrelated kidney transplants (LURT) and analyzed the effect of early rejection upon graft survival.

METHODS

A retrospective analysis on 428 adult living donor kidney transplants was performed. Graft function and survival were compared between LRT and LURT and risk factors for 1-year rejection were defined by multivariate analysis.

RESULTS

Between 1/1/97 and 12/31/01, 308 LRT and 120 LURT were performed at the University of California San Francisco. Donor age and number of mismatches were significantly higher in the LURT group. Patient and graft survival were similar in both groups. After a median follow-up of 26 months, graft survival was 94.8% (LRT) versus 93.3% (LURT). Five-year serum creatinine levels were comparable in both populations. One-year rejection was higher in the LURT group (30% vs. 18.5%; P<0.01). Rejection was influenced by the number of human leukocyte antigen mismatches. Other independent risk factors for early rejection were poor initial graft function, donor age greater than 55 years, and recipient body mass index greater than 30. Patients with poor initial graft function and early rejection had a statistically greater incidence of subtherapeutic tacrolimus trough levels on postoperative day 7.

CONCLUSIONS

Despite a higher incidence of early rejection, LURT show similar function and survival compared with LRT. In high-risk patients receiving living unrelated renal transplants, consideration should be given to intensify initial immunosuppression to prevent early rejection episodes.

Early graft function after living donor kidney transplantation predicts rejection but not outcomes

Poor early graft function (EGF) after deceased donor kidney transplantation (DDKT) has been intensely studied. Much less is known about poor EGF after living donor kidney transplantation (LDKT). Data were collected on 469 LDKTs performed between 1/1/97 and 12/31/01 to determine risk factors for and outcomes associated with poor EGF, defined as either delayed or slow graft function (DGF or SGF). The incidence of DGF and SGF were 4.7% and 10.7%, respectively. Diabetic etiology (OR 2.22; p = 0.021) and warm ischemia time (WIT) (OR 1.05 per min increment; p = 0.0025) emerged as independently associated with poor EGF. Neither functional graft survival nor 1-year graft function differed among the EGF groups. However, DGF and SGF strongly predisposed to acute rejection (AR), which compromised functional graft survival (p = 0.0007) and 1-year graft function. Therefore, we conclude that diabetic etiology of renal disease and WIT are the dominant risk factors for poor EGF after LDKT. Poor EGF did not directly compromise functional graft survival but strongly predisposed to AR. We suggest that immunosuppression should be intensified in the poor EGF setting to maximize LDKT longevity, as AR does impair functional graft survival.

Influence of donor pretreatment with N-acetylcysteine on ischemia/reperfusion injury in rat kidney grafts

PURPOSE

N-acetylcysteine (NAC) has been shown to ameliorate ischemic acute renal failure. We determined the effect of donor pretreatment with NAC on ischemia reperfusion (I/R) injury in rat kidney grafts.

MATERIALS AND METHODS

Lewis rats were divided into 3 groups (8 per group) and treated with saline, mannitol (1 gm/kg) or NAC (1 gm/kg intravenously) prior to donor nephrectomy. Cold stored kidneys (24 hours in UW solution) were transplanted into bilaterally nephrectomized recipients. Blood and graft tissue samples were taken 24 hours after transplantation for assessment of metabolic changes, histological damage and renal function. Metabolites associated with renal I/R injury were quantified in blood and renal tissue by magnetic resonance spectroscopy.

RESULTS

The degree of histological damage was similar between the treatment groups. Of the counted tubules 60%were mildly damaged, whereas 40% showed moderate damage. Measurement of the metabolites allantoin and trimethylamine-N-oxide (TMAO) indicated a beneficial effect of NAC treatment. In graft tissue and recipient blood allantoin, a uric acid metabolite, was significantly lower in the NAC group vs the mannitol and saline groups (p <0.05). In recipient blood TMAO, an established marker of renal medullary injury, was significantly decreased in the NAC group vs mannitol and saline (p <0.05). Serum creatinine levels were not different between treatment groups.

CONCLUSIONS

Donor pretreatment with NAC preserves renal metabolism and may improve outcomes of I/R injured kidney transplants. Allantoin and TMAO are sensitive metabolic markers of renal I/R injury that can be detected before the onset of functional and morphological changes.

Sirolimus delays recovery of rat kidney transplants after ischemia-reperfusion injury

BACKGROUND

Sirolimus (SRL) seems to impair renal recovery from ischemic injury in animal models and delayed graft function after clinical renal transplantation. This study determined the impact of SRL on renal recovery after ischemia-reperfusion injury in a rat kidney transplant model.

METHODS

Syngeneic kidneys were preserved in University of Wisconsin solution before transplantation into bilaterally nephrectomized rats. Recipients received vehicle or SRL targeting for whole-blood trough levels of 10 to 20 ng/mL as measured by high-performance liquid chromatography. Renal function was assessed by animal survival or daily serum creatinine. Tissue samples were collected for histologic examination.

RESULTS

Median SRL whole-blood concentrations were 16.6 +/- 1.6 ng/mL on postoperative day (POD) 1 and 12.0 +/- 0.9 ng/mL on POD 3. Transplantation of kidneys after 39 hr of cold storage resulted in 30% survival in the SRL-treated group compared with 100% survival in the control group (P=0.002). Transplantation of kidneys after 24 hr of cold storage resulted in no survival differences, but there were significant differences in renal function. Daily serum creatinine (PODs 1-4) was higher in the SRL-treated group compared with the control group (P<0.05 at all time points). Grafts from SRL-treated animals showed more severe tubular necrosis compared with control animals.

CONCLUSIONS

When given at therapeutic immunosuppressive doses, SRL compromises renal function after ischemia-reperfusion injury in a rat kidney transplant model. The antiproliferative effect of SRL may translate into impairment of tubular repair and regeneration necessary for recovery after such injury.

Management of lymphoceles after renal transplantation: laparoscopic versus open drainage

PURPOSE

Laparoscopic surgery has become widely accepted for the treatment of lymphoceles following kidney transplantation. In this single center study we retrospectively reviewed our results of the surgical management of post-transplant lymphoceles, assessing indication and outcome of laparoscopic versus open drainage.

MATERIALS AND METHODS

The records of 60 patients who underwent surgical treatment for a symptomatic lymphocele following kidney transplantation or combined kidney/pancreas transplantation were retrospectively reviewed.

RESULTS

Between 1995 and 2002, 1,836 patients received a kidney transplant at the University of California San Francisco. In 60 patients (3.3%) a symptomatic lymphocele developed and either laparoscopic (20) or open drainage (40) was completed. The conversion rate from laparoscopic to open drainage was 16.5%. The most common indications for open lymphocele drainage were noninfectious wound complications (13 patients) and a high risk of vessel or ureter injury (8) due to proximity of the lymphocele to hilar structures. Additional surgery on the graft was required in 5 patients. Intraoperative blood loss was significantly lower in the laparoscopy group. Median hospital stay was 1 day in the laparoscopy group versus 4 days in the open drainage group. No perioperative complications were observed in either group. After a median followup of 38 months, 2 patients in each treatment group had a symptomatic recurrence.

CONCLUSIONS

Although both surgical approaches are safe and effective, laparoscopic drainage should remain the method of choice for the treatment of post-transplant lymphocele. However, open drainage should be performed in patients with wound complications and in those with a small lymphocele adjacent to vital renal structures.

Reduction of severe ischemia/reperfusion injury in rat kidney grafts by a soluble P-selectin glycoprotein ligand

BACKGROUND

Inflammatory leukocyte-endothelium interactions, mediated by selectins, contribute to renal ischemia/reperfusion (I/R) injury. We examined the influence of the soluble P-selectin glycoprotein ligand 1 (sPSGL) on early I/R-induced changes in a rat kidney transplantation model with long cold ischemia.

METHODS

After 24 hr of cold storage, syngeneic kidneys were grafted into bilaterally nephrectomized rats. Before transplantation, recipients received either 1 mg/kg of sPSGL or vehicle (n=8 per group). Six hours after reperfusion, grafts were removed for light microscopy and immunohistochemistry. Capillary blood flow was measured under a fluorescence microscope by using the concentric-circles method.

RESULTS

A greater proportion, 74.7+/-7.2% (sPSGL) vs. 28+/-7.4% (controls), of all dye-labeled outer medullary capillaries appeared in the 12-microm radius (P<0.01), indicating dense blood flow, whereas 7.6+/-2.9% vs. 43.3+/-9.7%, respectively, appeared in the 60-microm radius (P<0.05), indicating rarefied blood flow. In the sPSGL-treated group, the extent of severe tubular damage within the inner stripe of the outer medulla was lower compared with controls (37.5+/-8.3% vs. 78.4+/-3.5%, P<0.01). Outer medullary heat shock protein 72 expression was 14.5+/-1.6% in the sPSGL-treated group compared with 9.6+/-1.4% in controls (P<0.05). The number of infiltrating polymorphonuclear leukocytes was similar in both groups. Treatment with sPSGL had no influence on the serum creatinine level.

CONCLUSIONS

Our data suggest that impairment of outer medullary blood flow is crucial in I/R injury of kidney grafts with prolonged cold storage. Reduction of capillary blood flow perturbations by sPSGL protects tubular cells from severe structural damage. Blocking early selectin-mediated leukocyte adhesion may have therapeutic implications in improving the prognosis of renal transplants with severe I/R injury.