Warm ischemia less than 30 minutes is not necessarily safe during partial nephrectomy: Every minute matters

Comparison of Outcomes Between Partial and Radical Laparoscopic Nephrectomy for Localized Renal Tumors Larger Than Four Centimeters: A Systematic Review and Meta-Analysis

Background

Earlier studies have juxtaposed different laparoscopic methods for treating renal tumors; however, extensive evidence with a particular focus on large kidney tumors remains lacking. The objective of this meta-analysis was to assess the perioperative outcomes, kidney performance, and cancer-related results of laparoscopic partial nephrectomy (LPN) versus laparoscopic radical nephrectomy (LRN) for treating extensive, localized, non-metastatic kidney tumors (cT1b-cT2N0M0).

Methods

We systematically searched multiple databases from database inception until December 2023 for relevant studies. Selected data were analyzed with the Cochrane Collaboration's Review Manager 5.4 software using a random-effects model. Outcomes were expressed as odds ratios and weighted mean differences with 95% confidence intervals, considering a P value of < 0.05 as significant.

Results

Data from nine studies encompassing 1,303 patients (529 LPN, 774 LRN) revealed that LPN was associated with lengthier surgeries and increased blood loss compared to LRN. While LPN exhibited higher postoperative complication rates, the disparity did not reach statistical significance. LPN led to improved postoperative renal function, manifesting as a reduced estimated glomerular filtration rate (eGFR) decline and fewer incidents of new chronic kidney disease cases. Both groups demonstrated comparable tumor recurrence and overall mortality rates, but LPN exhibited significantly lower cancer-specific mortality rates.

Conclusions

LPN, despite longer operative times and greater intraoperative blood loss, was found to be superior to LRN in preserving postoperative renal function. Oncologically, LPN and LRN have comparable overall mortality rates, but LPN showed a significant advantage in terms of lower cancer-specific mortality rates.

Tracing the evolving dynamics and research hotspots in the kidney neoplasm and nephron sparing surgery field from the past to the new era

BACKGROUND

With increasing detection of small renal masses and accumulating evidence that nephron sparing surgery (NSS) could achieve oncological equivalence and functional superiority compared with radical nephrectomy (RN), NSS has become first-line therapy for some patients with localized renal masses.

OBJECTIVE

This study aims to review the publications in the kidney neoplasm and NSS field, exploring the research hotspots.

METHOD

Kidney neoplasm and NSS related publications before July 3th 2023 were obtained from the Web of Science Core Collection database. We then used bibliometric analysis to conduct performance analysis, citation analysis and co-citation network of publications, together with keyword co-occurrence analysis.

RESULTS

Seven thousand five hundred and sixty-four documents were finally retrieved, and the annual publications increased exponentially. The most productive authors were "KAOUK JH" and "GILL IS", while USA, and 12 American affiliations such as CLEVELAND CLINIC FOUNDATION and MAYO CLINIC were far leading in this field. Journal of Urology and European Urology were journals with the highest citations and h-index.

DISCUSSION

Through literature reviewing plus co-occurrence and clustering analysis, the therapeutic effects of partial nephrectomy (PN) versus RN on patients with localized renal cell carcinoma, different operative approaches of PN, and conservative NSS methods were deemed as the most focused topics.

CONCLUSION

Three aspects were the most important hotspots in this field. Firstly, how to provide the optimal management choices for different patients. Secondly, therapeutic effects of different management options and surgical techniques needed more prospective and randomized studies. Finally, more novel technologies and surgical techniques were required.

Comprehensive Overview of Innovative Strategies in Preventing Renal Ischemia-reperfusion Injury: Insights from Bibliometric and In silico Analyses

BACKGROUND

Ischemia-reperfusion Injury (IRI) is a complex pathophysiological process with severe consequences, including irreversible loss of renal function. Various intraoperative prevention methods have been proposed to mitigate the harmful effects of warm ischemia and kidney reperfusion.

AIM

This comprehensive analysis provides an overview of pharmacological agents and intraoperative methods for preventing and treating renal IRI.

METHODS

Our analysis revealed that eplerenone exhibited the highest binding affinity to crucial targets, including Aldehyde Dehydrogenase (AD), Estrogen Receptor (ER), Klotho protein, Mineralocorticoid Receptor (MR), and Toll-like Receptor 4 (TLR4). This finding indicates eplerenone's potential as a potent preventive agent against IRI, surpassing other available therapeutics like Benzodioxole, Hydrocortisone, Indoles, Nicotinamide adenine dinucleotide, and Niacinamide. In preventing kidney IRI, our comprehensive analysis emphasizes the significance of eplerenone due to its strong binding affinity to key targets involved in the pathogenesis of IRI.

RESULTS

This finding positions eplerenone as a promising candidate for further clinical investigation and consideration for future clinical practice.

CONCLUSION

The insights provided in this analysis will assist clinicians and researchers in selecting effective preventive approaches for renal IRI in surgical settings, potentially improving patient outcomes.

Holographic 3D renal segments reconstruction protects renal function by promote choice of selective renal artery clamping during robot-assisted partial nephrectomy

OBJECTIVE

To investigate the impact of selective artery clamping (SAC) and main artery clamping (MAC) during robot-assisted partial nephrectomy (RAPN) on renal function and the influence of holographic three-dimensional (3D) reconstruction of renal segments on the selection between SAC and MAC.

METHODS

This retrospective observational study included patients who underwent RAPN at First Hospital Affiliated to the Army Medical University between December 2016 and July 2022. According to the clamping methods, the patients were divided into the SAC group and the MAC group. The primary outcome was renal function.

RESULTS

A total of 422 patients (194 in the SAC group and 228 in the MAC group) were included. The RAPN procedures were all completed successfully. The patients in SAC group had less glomerular filtration rate (GFR) decline in the affected kidney (8.6 ± 7.0 ml/min vs. 18.7 ± 10.9 ml/min, P < 0.001) and minor estimated glomerular filtration rate (eGFR) decrease (4.3 ± 10.5 ml/min vs. 12.6 ± 12.1 ml/min, P < 0.001) than those in MAC group. Among 37 patients with baseline renal insufficiency, the GFR decline of the affected kidney in the SAC subgroup was significantly lower than in the MAC subgroup (5.5 ± 6.5 ml/min vs. 14.3 ± 9.2 ml/min, P = 0.002). The proportion of patients who underwent 3D reconstruction was significant higher in the SAC group than in the MAC group. (65.46% vs. 28.07%, P < 0.001).

CONCLUSION

The SAC technique during RAPN may serve as a protective measure for renal function, while the implementation of holographic 3D renal segment reconstruction technique may facilitate optimal selection of SAC.

Open versus robot-assisted partial nephrectomy for highly complex renal masses: a meta-analysis of perioperitive and functional outcomes

Robot-assisted partial nephrectomy (RAPN) is increasingly being used for the complex surgical management of renal masses. The comparison of RAPN with open partial nephrectomy (OPN) has not yet led to a unified conclusion with regard to perioperative outcomes. To conduct a systematic review and meta-analysis of the literature on the perioperative outcomes of RAPN compared with OPN. We performed a systematic search in PubMed, Embase, Web of Science, and Cochrane Library database for randomized control trials (RCTs) and non-RCTs that compare OPN to RAPN. The primary outcomes included perioperative, functional and oncologic. The odds ratio (OR) and weighted mean difference (WMD) were applied for the comparison of dichotomous and continuous variables with 95% confidence intervals (CIs). Five studies, comprising 936 patients, were included in the meta-analysis. Our findings indicated that there were no significant differences in blood loss, minor complication rate, eGFR decline from baseline, positive surgical margin, and ischemia time between OPN and RAPN. However, RAPN was associated with a shorter hospital stay (WMD 1.64 days, 95% CI - 1.17 to 2.11; p < 0.00001), lower overall complication rate (OR 1.72, 95% CI 1.21-2.45; p < 0.002), lower transfusion rate (OR 2.64, 95% CI 1.39-5.02; p = 0.003) and lower major complication rate (OR 1.76, 95% CI 1.11-2.79; p < 0.02) compared to OPN. Additionally, the operation time for OPN was shorter than that for RAPN (WMD - 10.77 min, 95% CI - 18.49 to - 3.05, p = 0.006). In comparison with OPN, RAPN exhibits better results in terms of hospital stay, overall complications, blood transfusion rate, and major complications, with no significant difference in intraoperative blood loss, minor complications, PSM, ischemia time, and short-term postoperative eGFR decline. However, the operation time of OPN is slightly shorter than that of RAPN.

Mean Warm Ischemia Time among Kidney Transplant Patients in a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

In renal transplantation, warm ischemia time is the interval from the removal of a procured kidney from ice storage to initiating graft reperfusion. Successful kidney transplantation depends on warm ischemia time. The study aims to find the mean warm ischemia time among kidney transplant patients in a tertiary care centre.

Methods

This descriptive cross-sectional study was conducted among kidney transplant patients in a tertiary care centre. Data from 15 December 2012 to 15 October 2022 were collected between 1 December 2022 to 4 January 2023 from the hospital records. Ethical approval was taken from the Nepal Health Research Council (Reference number: 1341). All first-time living-related kidney transplant recipients were included in the study. All the patients undergoing kidney transplants from brain-dead donors were excluded from the study. Convenience sampling method was used. Point estimate and 95% Confidence Interval were calculated.

Results

Among 230 patients, the mean warm ischemia time was 35.45±7.35 min. The mean first warm ischemia time was 4.28±2.05 min and the mean second warm ischemia time was 31.27±7.04 min. The mean age of the recipients was 35.14±10.49 years (range 14-64), of which 173 (75.20%) were male and 57 (24.80%) were female.

Conclusions

The mean warm ischemia time among kidney transplant patients in a tertiary care centre was similar to the studies done in similar settings.

Keywords

kidney transplantation; prevalence; warm ischemia.

Insulating jackets thermally protect kidneys in an ex vivo model of second warm ischemia

BACKGROUND

Kidney transplantation is the current optimal treatment for suitable patients with end-stage renal disease. The second warm ischemic time (SWIT) is known to negatively impact delayed graft function, and long-term graft survival, and methods are required to ameliorate the impacts of SWIT on transplantation outcomes.

MATERIALS AND METHODS

This study primarily focused on determining the effect of a novel thermally insulating jacket on the thermal profile of the human kidney and quantifying the reduction in thermal energy experienced using this device (KPJ™). An ex vivo simulated transplantation model was developed to determine the thermal profiles of non-utilized human kidneys with and without KPJ™ (n = 5). Control kidney temperature profiles were validated against the temperature profiles of n = 10 kidneys during clinical kidney transplantation.

RESULTS

Using the ex-vivo water bath model, the thermally insulated human kidney reached the 15°C metabolic threshold temperature at 44.5 ± 1.9 min (vs control: 17.3 ± 1.8 min (p = 0.00172)) and remained within the 18°C threshold until 53.3 ± 1.3 min (vs control: 20.9 ± 2.0 min (p = 0.002)). The specific heat capacity of KPJ™ protected kidney was four-fold compared to the control kidney. The clinical temperature audit, closely correlated with the water bath model, hence validating this ex-vivo human kidney transplant model.

CONCLUSION

Intraoperative thermal protection is a simple and viable method of reducing the thermal injury that occurs during the SWIT and increasing the specific heat capacity of the system. Such technology could easily be translated into clinical kidney transplant practice.

Operating room team strategies to reduce flow disruptions in high-risk task episodes: resilience in robot-assisted surgery

In healthcare work settings, flow disruptions (FDs) pose a potential threat to patient safety. Resilience research suggests that adaptive behavioural strategies contribute to preventing cognitive overload through FDs at crucial moments. We aimed to explore the nature and efficacy of operating room (OR) team strategies to prevent FDs in robot-assisted surgery. Within a mixed-methods design, we first asked surgical professionals, which strategies they apply, and secondly, identified behavioural strategies through direct observations. Findings were analysed using content analysis. Additionally, FDs were assessed through live observations in the OR. The sample included four interviewed experts and 15 observed surgical cases. Sixty originally received strategies were synthesised into 17 final OR team strategies. Overall, 658 FDs were observed with external FDs being the most frequent. During high-risk episodes, FDs were significantly reduced (p < 0.0001). The identified strategies reveal how OR teams deliberatively and dynamically manage and mitigate FDs during critical tasks. Our findings contribute to a nuanced understanding of adaptive strategies to safeguard performance in robot surgery services. Practitioner Summary: Flow disruptions (FDs) in surgical work may become a severe safety threat during high-risk situations. With interviews and observations, we explored team strategies applied to prevent FDs in critical moments. We obtained a comprehensive list of behavioural strategies and found that FDs were significantly reduced during a specific high-risk surgical task. Our findings emphasise the role of providers' and teams' adaptive capabilities to manage workflow in high-technology care environments.

Protection From the Second Warm Ischemic Injury in Kidney Transplantation Using an Ex Vivo Porcine Model and Thermally Insulating Jackets

BACKGROUND

Kidney transplantation is the optimum treatment for kidney failure in carefully selected patients. Technical surgical complications and second warm ischemic time (SWIT) increase the risk of delayed graft function (DGF) and subsequent short- and long-term graft outcomes including the need for post-transplant dialysis and graft failure. Intraoperative organ thermal regulation could reduce SWIT, minimizing surgical complications due to time pressure, and limiting graft ischemia-reperfusion injury.

METHODS

A novel ischemic-injury thermal protection jacket (iiPJ) was designed and fabricated in silicone composite and polyurethane (PU) elastomer prototypes. Both were compared with no thermal insulation as controls. Time to reach ischemic threshold (15°C) and thermal energy transfer were compared. A water bath model was used to examine the thermal protective properties of porcine kidneys, as a feasibility study prior to in vivo translation.

RESULTS

In both iterations of the iiPJ, the time taken to reach the warm ischemia threshold was 35.2 ± 1.4 minutes (silicone) and 38.4 ± 3.1 minutes (PU), compared with 17.2 ± 1.5 minutes for controls (n = 5, P < .001 for both comparisons). Thermal energy transfer was also found to be significantly less for both iiPJ variants compared with controls. There was no significant difference between the thermal performance of the 2 iiPJ variants.

CONCLUSION

Protection from SWIT by using a protective insulation jacket is feasible. With clinical translation, this novel strategy could facilitate more optimal surgical performance and reduce transplanted organ ischemia-reperfusion injury, in particular the SWIT, potentially affecting delayed graft function and long-term outcomes.

A three-tier Rescue stent improves outcomes over balloon occlusion in a porcine model of noncompressible hemorrhage

BACKGROUND

Noncompressible hemorrhage remains a high-mortality injury, and aortic balloon occlusion poses limitations in terms of distal ischemic injury. Our hypothesis was that a retrievable Rescue stent would confer improved outcome over aortic balloon occlusion.

METHODS

A three-tier, retrievable stent graft was laser welded from nitinol and polytetrafluoroethylene to provide rapid thoracic and abdominal coverage with an interval bare metal segment to preserve visceral flow. Anesthetized swine had injury of the thoracic or abdominal aorta followed by balloon occlusion or a Rescue stent. A 1-hour long damage-control phase with blood repletion was used to simulate the prolonged interval between injury and repair, especially in the battlefield setting. Following the damage-control phase, the balloon or stent were retrieved followed by vascular repair and recovery to 48 hours. Animals were compared in terms of hemodynamics, blood loss, neurophysiologic spinal cord ischemia, ischemic organ injury, and survival.

RESULTS

Despite antegrade hemorrhage control, balloon occlusion averaged 3.5 L of retrograde hemorrhage, loss of visceral perfusion, and permanent spinal cord ischemia by neurophysiology in six of seven animals. After permanent repair, all balloon occlusion animals died with only a single short term (5 hours) survivor. Conversely, Rescue stent animals revealed rapid hemorrhage control (in under 2 minutes) whether the injury was thoracic or abdominal with improved hemodynamics, preserved visceral flow, reduced spinal cord ischemia, negligible histologic organ injury and survival to end of study in all abdominal injured animals (n = 6) and four of six thoracic injured animals, with two deaths related to arrhythmia.

CONCLUSION

Compared with aortic balloon occlusion, a Rescue stent offers superior hemorrhage control and survival by virtue of reduced ischemic injury and direct control of the hemorrhagic injury. The Rescue stent may become a useful tool for damage control, especially on the battlefield where definitive repair presents logistical challenges.

Robot-assisted retroperitoneal laparoscopic partial nephrectomy without hilar occlusion VS classic robot-assisted retroperitoneal laparoscopic partial nephrectomy: A retrospective comparative study

To discuss the feasibility, safety, and effectiveness of off-clamp robotic partial nephrectomy via retroperitoneal approach and provide data for evidence based medicine in the surgical treatment of renal tumor.The clinical data was documented and compared between robotic retroperitoneal partial nephrectomy with and without hilar occlusion (clamp group and off-clamp group) performed between January 1, 2015 and December 31, 2017.Six-months post-operative renal function was superior in the off-clamp group compared with clamp group, while long-term results remained to be elucidated. No significant difference in post-operative hospital stay was found between the 2 groups. Estimated blood loss in off-clamp group was significantly higher than clamp group, while no significant difference was found in transfusion rate.Off-clamp robotic partial nephrectomy via retroperitoneal approach is a safe and effective technique for the removal of renal tumor while the indication of surgery is strictly limited to small (<4 cm) and exophytic renal tumor.

Implantation Warm Ischemia Time in Kidney Transplant Recipients: Defining Its Limits and Impact on Early Graft Function

Background

Prolonged cold ischemia is an established risk factor for poor early graft function (EGF). However, warm ischemia incurring during graft implantation has received little attention regarding its possible detrimental effect on EGF. The aim of our study was to examine the impact of recipient warm ischemia time on EGF.

Material/Methods

The data of 102 consecutive kidney transplants were analyzed to determine the association between duration of graft implantation time (IT) and EGF. Recipient IT groups were (GI) up to 45 min, (GII) 45–60 min, and (GIII) >60 min. EGF was categorized as immediate (IGF), slow (SGF), or delayed graft function (DGF). In recipients with IGF, graft function was further assessed by time needed for reduction in serum creatinine by 50% (SC50) of pre-transplant value, and serum creatinine on day 7 (SCD7).

Results

Of a total of 102 recipients, 55 (55%) were in GI, 33 (32%) were in GII, and 14 (13%) were in GIII. Factors prolonging IT were recipient body mass index (BMI) (p=0.02) and multiple arteries in donor kidneys (p<0.01). No recipients in GI had DGF or SGF, while 2 in GII had DGF, and 5 patients in GIII had poor EGF. SC50 was significantly longer in GIII and GII versus GI (40.8±42.4 and 32.8±20.4 vs. 22.2±17.2 [p=.02, p≤.01]), respectively. Mean SCD7 was also significantly higher in GIII and GII versus GI. The mean last serum creatinine was comparable among all groups.

Conclusions

IT of more than 45 min was a risk factor for poor EGF, but achieved statistical significance only when it exceeded 60 min. Longer IT also significantly slowed the fall in SC50, and led to a higher SCD7. However, poor EGF and suboptimal early SC trends had little long-term effect on serum creatinine.

Isoflurane Increases Tolerance to Renal Ischemia Reperfusion Injury Compared to Propofol: An Experimental Study in Pigs

Purpose: To compare two clinically relevant anesthetic agents, i.e., isoflurane versus propofol with respect to protection of the kidney in a porcine renal ischemia reperfusion model. Materials and Methods: 14 hybrid pigs were randomized to anesthesia with either isoflurane or propofol prior to laparoscopic surgery. Following anesthesia, the left kidney hilum was clamped for 60 min and the right kidney removed. After 48 h of reperfusion, urine was sampled for analysis of neutrophil gelatinase-associated lipocalin (NGAL), albumin, and creatinine. The left kidney was harvested for histologic scoring of injury. Results: Histologic examination of renal injury revealed a statistically significant difference in favor of isoflurane on denuded basement membrane score (isoflurane group 1.58 ± 0.38 vs. propofol 2.42 ± 0.80, p = .026). Median (25-75 percentile) urinary albumin 3.4 g/L (2.25-7.48) vs. 8.9 g/L (3.73-13.8), (p = .041) and urinary albumin/creatinine ratio 1.17 (0.76-1.82) vs. 1.76 (1.63-5.99), (p = .026) were both significantly lower in the isoflurane group. Median (25-75 percentile) urinary NGAL was 167 (51-215) pg/ml in the isoflurane group compared with 362 (149-508) pg/ml in the propofol group (p = .093). Conclusion: Isoflurane increases tolerance to renal ischemia reperfusion injury compared to propofol in this model.

Laparoscopic Partial Nephrectomy: A Narrative Review and Comparison with Open and Robotic Partial Nephrectomy

INTRODUCTION

Kidney cancer ranks among the top 10 most prevalent cancers in Western society, ∼90% of which are renal cell carcinomas. There has been a paradigm shift in the management of small renal masses with strong emphasis now placed on nephron-sparing surgery and increased utilization of laparoscopic approaches to partial nephrectomy. In this review, the current state of laparoscopic partial nephrectomy (LPN) is discussed.

EVIDENCE ACQUISITION

The PubMed database was queried using the MeSH terms "laparoscopy" and "nephrectomy," as well as the search term "partial." A search was performed filtering for "clinical trial," "review," "humans", and "English."

EVIDENCE SYNTHESIS

Articles that discussed intraoperative techniques, functional and oncologic outcomes, and a comparison between robot-assisted partial nephrectomy and LPN were synthesized.

CONCLUSION

LPN reduces ischemia time, affords equivalent functional outcomes, oncologic outcomes, and equivalent complication rates compared with open partial nephrectomy. Future advances in laparoscopic technique and advancements in robotic technology offer potential to improve surgical and patient outcomes.

The relationship between renal warm ischemia time and glomerular loss. An experimental study in a pig model

Purpose:

To investigate the glomerular number after different warm ischemia times.

Methods:

Thirty two pigs were assigned into four groups. Three groups (G10, G20, and G30) were treated with 10, 20, and 30 minutes of left renal warm ischemia. The sham group underwent the same surgery without renal ischemia. The animals were euthanized after 3 weeks, and the kidneys were collected. Right kidneys were used as controls. The kidney weight, volume, cortical-medullar ratio, glomerular volumetric density, volume-weighted mean glomerular volume, and the total number of glomeruli per kidney were obtained. Serum creatinine levels were assessed pre and postoperatively.

Results:

Serum creatinine levels did not differ among the groups. All parameters were similar for the sham, G10, and G20 groups upon comparison of the right and left organs. The G30 group pigs' left kidneys had lower weight, volume, and cortical-medullar ratio and 24.6% less glomeruli compared to the right kidney. A negative correlation was found between warm ischemia time and glomerular number.

Conclusions:

About one quarter of glomeruli was lost after 30 minutes of renal warm ischemia. No glomeruli loss was detected before 20 minutes of warm ischemia. However, progressive glomerular loss was associated with increasing warm ischemia time.

Effects of differential-phase remote ischemic preconditioning intervention in laparoscopic partial nephrectomy: A single blinded, randomized controlled trial in a parallel group design

STUDY OBJECTIVE

There are two windows of protection for remote ischemic preconditioning (RIPC), an early (ERIPC) and a late-phase (LRIPC). While ERIPC has been well studied, works on LRIPC are relatively scarce, especially for the kidneys. We aimed to compare the effects of early-phase versus late-phase RIPC in patients with laparoscopic partial nephrectomy (LPN).

DESIGN

A randomized controlled study SETTING: The Second Affiliated Hospital of Anhui Medical University, 1 May 2012 to 30 October 2013 PATIENTS: Sixty-five ASA 1 to 2 patients scheduled for LPN were located randomly to ERIPC group, LRIPC group and CON group (control).

INTERVENTIONS

Three five-minute cycles of right upper limb ischaemia and reperfusion were performed after induction of anesthesia in ERIPC group. Patients in LRIPC group received similar treatment 24h before surgery, while control patients were not subjected to preconditioning.

MEASUREMENTS

Serum neutrophil gelatinase-associated lipocalin (NGAL) and serum cystatin C (CysC) were evaluated before the induction of anesthesia (0h), 2h (2h) and 6h (6h) after surgery. Unilateral glomerular filtration rates (GFR) were assessed before and after surgery to evaluate overall renal function.

MAIN RESULTS

Serum NGAL and CysC were significantly lower in ERIPC and LRIPC groups at 2h post-operation (P<0.001), 6h post-operation (P<0.001). Additionally, The GFR were significantly lower in ERIPC and LRIPC groups than in CON group at the 3rd month after surgery (P=0.019; P<0.001). Moreover, compared to the ERIPC group, concentration of NGAL and CysC in LRIPC group decreased to a greater extent, while GFR and the percentage of decrement was significantly less in the LRIPC group (P=0.016; P<0.001).

CONCLUSIONS

Regardless of early-phase or late-phase intervention, limb remote ischemic preconditioning confers protection on renal ischemia-reperfusion injury in patients with laparoscopic partial nephrectomy, and the late-phase protection is more prominent.

Ischemia and Functional Recovery from Partial Nephrectomy: Refined Perspectives

BACKGROUND

Nephron mass preservation is a key determinant of functional outcomes after partial nephrectomy (PN), while ischemia plays a secondary role. Analyses focused specifically on recovery of the operated kidney appear to be most informative, yet have only included limited numbers of patients.

OBJECTIVE

To evaluate the relative impact of parenchymal preservation and ischemia on functional recovery after PN using a more robust cohort allowing for more refined perspectives about ischemia.

DESIGN, SETTING, AND PARTICIPANTS

A total of 401 patients managed with PN with necessary studies were analyzed for function and nephron mass preserved specifically within the kidney exposed to ischemia.

INTERVENTION

PN.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The nephron mass preserved was measured from computed tomography scans <2 mo before and 3-12 mo after PN. Patients with two kidneys were required to have nuclear renal scans within the same timeframes. Recovery from ischemia was defined as the percent function preserved normalized by the percent nephron mass preserved. Pearson correlation was used to evaluate relationships between functional recovery and nephron mass preservation or ischemia time. Multivariable linear regression assessed predictors for recovery from ischemia.

RESULTS AND LIMITATIONS

The median tumor size was 3.5cm and the median RENAL score was 8. Cold and warm ischemia were utilized in 151 and 250 patients, and the median ischemia time was 27 and 21min, respectively. The function preserved was strongly correlated with nephron mass preserved(r=0.63; p<0.001). Median recovery from ischemia was significantly higher for hypothermia (99% vs 92%; p<0.001) and remained consistently strong even with longer duration. Multivariable analysis demonstrated that recovery from ischemia, which normalizes for nephron mass preservation, was significantly associated with ischemia type and duration (both p<0.05). However, each additional 10min of warm ischemia was associated with only a 2.5% decline in recovery from ischemia. Limitations include the retrospective design.

CONCLUSIONS

Our data suggest that functional recovery from clamped PN is most reliable with hypothermia. Longer intervals of warm ischemia are associates with reduced recovery; however, incremental changes are modest and may not be clinically significant in patients with a normal contralateral kidney.

PATIENT SUMMARY

Functional recovery after clamped partial nephrectomy is primarily dependent on preservation of nephron mass. Recovery is most reliable when hypothermia is applied. Longer intervals of warm ischemia are associated with reduced recovery; however, the incremental changes are modest.

Preoperative evaluation of renal artery in patients with renal tumor: Using noncontrast-enhanced magnetic resonance angiography

To investigate the feasibility of the noncontrast-enhanced magnetic resonance angiography (NCE-MRA) to evaluate renal arteries before partial nephrectomy (PN).Retrospective analyzed 479 patients who underwent renal surgery between January 2013 and December 2015 with NCE-MRA or computed tomographic angiography (CTA) renal artery image reconstruction preoperative in our department. The renal artery reconstruction score (RARS) was based on the level of artery visualization in a 4-class criterion, and the R.E.N.A.L nephrometry score (R.E.N.A.L), arterial based complexity (ABC) were also analyzed.Of the 479 patients, the overall-lever RARS was 3.62, and the average in 2 groups was no significant difference (NCE-MRA vs CTA, P = 0.072). The performance of NCE-MRA in PN group was similar with CTA. Further comparison demonstrated that the efficiency of NCE-MRA in moderate- or low-degree tumor according to the R.E.N.A.L and ABC complexity less than 3S was equal to CTA. However, high degree (P < 0.001), 3S (P = 0.027), or 3H (P < 0.001) would affect the imaging of renal artery. Intragroup analysis showed that tumor complexity such as max tumor size (r = -o.351, P < 0.001), R.E.N.A.L (r = -0.439, P < 0.001), and ABC (r = -0.619, P < 0.001) were closely correlated with the NCE-MRA performance. The images of 2 sides of the kidney were compared in single person as well, which was meaningful for NCE-MRA patients only (NCE-MRA, P < 0.001; CTA, P = 0.182).The renal artery reconstruction performed by NCE-MRA is feasible and has a similar achievement in the PN potential recipients, with a lower side effect, and meets the requirements for making surgical decision. It has a broad application prospect in clinical practice; however, it still needs to further improve the ability in more complex tumors.

Nephrometry score-guided off-clamp laparoscopic partial nephrectomy: patient selection and short-time functional results

BACKGROUND

Laparoscopic partial nephrectomy (LPN) is not a novel but a relatively technically challenging surgical procedure. Off-clamp LPN with zero ischemia can completely eliminate ischemic reperfusion injury to the kidney. The purpose of this study was to evaluate the safety and functional outcome of nephrometry score-guided off-clamp technique in LPN.

METHODS

A total of 44 patients underwent LPN between January 2015 and July 2015 for renal mass with radius, exophytic/endophytic, nearness to sinus, anterior/posterior location (RENAL) score 4 were enrolled. Twenty-two of them underwent off-clamp LPN with zero ischemia, and the other 22 received standard LPN with common renal artery clamp. Estimate blood loss (EBL), total operation time, resection time, renorrhaphy time, preoperative estimated glomerular filtration rate (eGFR), postoperative eGFR, eGFR change, and drainage after surgery were compared between these two groups using t test.

RESULTS

Patients' characteristics including gender, age, BMI, tumor size, and RENAL score were balanced between the two groups. Average EBL was more in the off-clamp group than in the on-clamp group (134.32 versus 70.23 ml, p = 0.001). Average eGFR change was less in the off-clamp group than in the on-clamp group (-1.56 versus -6.45, p < 0.001). Average drainage after surgery was 203.41 ml for the off-clamp group and 145.46 ml for the on-clamp group, p = 0.062. No urinary leakage and hematuria occurred in both groups. There were no statistical difference in total operation time, resection time, renorrhaphy time, preoperative eGFR, and postoperative eGFR between the two groups.

CONCLUSIONS

Off-clamp LPN is a safe and feasible approach to excise certain kidney tumors with RENAL score 4. This technique can better preserve kidney function without ischemic reperfusion injury.

Unilateral Partial Nephrectomy with Warm Ischemia Results in Acute Hypoxia Inducible Factor 1-Alpha (HIF-1α) and Toll-Like Receptor 4 (TLR4) Overexpression in a Porcine Model

Purpose

Ischemia/reperfusion (I/R) during partial nephrectomy (PN) contributes to acute kidney injury (AKI), which is inaccurately assessed using existent clinical markers of renal function. We evaluated I/R-related changes in expression in hypoxia inducible factor 1α (HIF-1α) and toll-like receptor 4 (TLR4), within kidney tissue and peripheral blood leukocytes (PBL) in a porcine model of PN.

Materials and Methods

Three adult pigs each underwent unilateral renal hilar cross clamping for 180 min followed by a 15 min reperfusion. The contralateral kidney served as control. Biopsies of clamped kidneys were obtained at baseline (time 0), every 60 min during the hypoxic phase, and post-reperfusion. Control kidneys were biopsied once at 180 min. Peripheral blood was sampled at time 0, every 30 min during the hypoxic phase, and post-reperfusion. HIF-1α and TLR4 expression in kidney tissue and PBL were analyzed by Western blotting. I/R-related histological changes were assessed.

Results

Expression of HIF-1α in clamped kidneys and PBL was below detection level at baseline, rising to detectable levels after 60 min of hypoxia, and continuing to rise throughout the hypoxic and reperfusion phases. Expression of TLR-4 in clamped kidneys followed a similar trend with initial detection after 30–60 min of hypoxia. Control kidneys exhibited no change in HIF-1α or TLR-4 expression. I/R-related histologic changes were minimal, primarily mild tubular dilatation.

Conclusions

In a porcine model of PN, HIF-1α and TLR4 exhibited robust, I/R-related increases in expression in kidney tissue and PBL. Further studies investigating these molecules as potential markers of AKI are warranted.

Robot-assisted partial nephrectomy in 95 consecutive patients: Oncological and functional outcomes at 3 years of follow-up

BACKGROUND

We present the oncological and functional results from a series of 43 patients with renal tumours, treated consecutively with robot-assisted partial nephrectomy (RPN).

MATERIALS AND METHOD

Between 2010 and 2014, we performed 95 RPNs. To assess the results, we included only those patients (n=43) who had a minimum follow-up of 2 years. A descriptive analysis was conducted of the demographic characteristics and perioperative variables. We employed Kaplan-Meier curves to assess overall survival, cancer-specific survival and recurrence-free survival.

RESULTS

The patients' mean age was 53.1±13.5 years. The mean preoperative tumour size was 3.7±2.3cm. The mean surgical time was 102.2±37.1min. The mean ischemia time was 21.27±7.74minutes, with a median intraoperative bleeding volume of 150mL (IQR, 87.5-425). There was a 7% rate of postoperative complications (Clavien≥III). There was no mortality. The average Fürhman grade was 2.5±0.56. There were no positive surgical margins or local recurrences. The median follow-up was 38±8 months, with an overal survival, recurrence-free survival and cancer-specific survival of 100% at 3 years of follow-up. The recurrence-free survival was 92,3% at 48 months of follow-up. The mean preoperative glomerular filtration rate was 91.04±28.17mL/min/1.73m(2), and the postoperative rate was 89.9±27.69mL/min/1.73m(2), with a nonsignificant reduction (P=.74).

CONCLUSIONS

The functional and oncological results of our series confirm the safety and efficacy of RPN. RPN offers optimal preservation of renal function and oncological control in the medium term.

Comparison of renal functional outcomes in exactly matched pairs between robot-assisted partial nephrectomy using warm ischemia and open partial nephrectomy using cold ischemia using diethylene triamine penta-acetic acid renal scintigraphy

PURPOSE

To compare renal functional outcomes in patients with a small renal mass undergoing robot-assisted partial nephrectomy using warm ischemia (wRAPN) or open partial nephrectomy using cold ischemia (cOPN).

METHODS

This study included 185 patients who underwent partial nephrectomy and were assessed by preoperative and postoperative diethylene triamine penta-acetic acid renal scintigraphy. Variables associated with postoperative operated-side glomerular filtration rate decrement (ΔGFR) were assessed using multivariate analysis. Exact 1:1 propensity score matching was performed using variables related to ΔGFR. Furthermore, 30 patients who underwent wRAPN were matched with 30 patients who underwent cOPN, and their differences in ΔGFR were calculated.

RESULTS

Patients who underwent cOPN were older (p = 0.025) and had shorter ischemia time (p < 0.001) than patients who underwent wRAPN. Multivariate analysis showed that surgical method, preoperative operated-side GFR and RENAL nephrometry score were significantly associated with operated-side ΔGFR. After propensity score matching, postoperative 3-month (14.8 vs. 7.3 mL/min/1.73 m(2), p = 0.057) and 1-year operated-side ΔGFR (11.4 vs. 2.8 mL/min/1.73 m(2), p = 0.031) was higher after wRAPN than after cOPN in patients with ischemia time ≥25 min, but did not differ in patients with ischemia time <25 min. Within the matched pairs, cOPN resulted in lower operated-side ΔGFR than wRAPN in patients with ischemia time ≥25 min (-6.9 mL/min/1.73 m(2), p = 0.047). Moreover, total GFR decrement was slightly lower with cOPN than with wRAPN (-7.2 mL/min/1.73 m(2), p = 0.086).

CONCLUSIONS

cOPN was superior to wRAPN in patients with a small renal mass and ischemia time ≥25 min. However, wRAPN yielded renal functional outcomes comparable to those of cOPN when ischemia time was <25 min.

[Partial nephrectomy on solitary kidney: Renal function outcome and predictive factors of impairment]

OBJECTIVES

To assess the postoperative functional outcome of PN in solitary kidney and define some predictive factors of renal change.

MATERIAL AND METHODS

A monocentric series of 45 partial nephrectomies on solitary kidneys, performed between 1988 and 2014, was retrospectively analyzed. Pre-, per- and postoperative clinicopathological data were collected in the UroCCR database. The evolution of early, medium and long-term postoperative Glomerular Filtration Rate (GFR) was evaluated. Predictive factors of GFR decline and hemodialysis were assessed in multivariate analysis.

RESULTS

Mean age was 61 years old (±10.8). Mean preoperative GFR and tumor size were respectively 59.6 mL/min (±18.7) and 3.9 cm (±2.6). Vascular clamping was performed in 41 cases (91%). Median time of warm ischemia was 20 minutes (2-60). Mean follow-up was 66 months (±47). Mean GFR at day 5, 1 month and last follow-up were respectively 46.4 mL/min, 50.3 mL/min and 53.1 mL/min. At day 5 and at last follow-up, a GFR decrease ≥ 20% was found in 20 patients (44.4%) and in 16 patients (35.5%), respectively. Five patients (11%) required definitive hemodialysis (HD) at last follow-up. At day 5, tumor size>4 cm (0.006) and operative time (P=0.003) were independent predictive factors of GFR decline. At 1 year, RENAL ns ≥ 10 was the only independent predictive factor of GFR alteration (P=0.0007). Preoperative GFR was significantly associated with final hemodialysis (P=0.023).

CONCLUSION

Partial nephrectomy allows most of the patients presenting with renal cell carcinoma on solitary kidney to be free of hemodialysis. Tumor complexity, tumor size and preoperative GFR seems to play a determinant role on postoperative functional outcome. These non-modifiable predictive factors should be recognized and taken into account to better select patients with high risk of postoperative renal failure.

LEVEL OF EVIDENCE

5.

Outlining the limits of partial nephrectomy

Amongst nephron-sparing modalities, partial nephrectomy (PN) is the standard of care in the treatment of renal cell carcinoma (RCC). Despite the increasing utilization of PN, particularly propagated by robot-assisted, minimally invasive approaches for small renal masses (SRMs), the limits of PN appear to be also evolving. In this review, we sought to address the tumour stage beyond which PN may be oncologically perilous. While the evidence supports PN in the treatment of tumours < pT2a, PN may have a role in advanced or metastatic RCC. Other scenarios wherein PN has limited utility are also explored, including anatomical or surgical factors that dictate the difficulty of the case, such as prior renal surgery. Lastly, we discuss the emerging role of molecular biomarkers, specifically epigenetics, to aid in the risk stratification of SRMs and to select tumours optimally suited for PN.

A Literature Review of Renal Surgical Anatomy and Surgical Strategies for Partial Nephrectomy

CONTEXT

A detailed understanding of renal surgical anatomy is necessary to optimize preoperative planning and operative technique and provide a basis for improved outcomes.

OBJECTIVE

To evaluate the literature regarding pertinent surgical anatomy of the kidney and related structures, nephrometry scoring systems, and current surgical strategies for partial nephrectomy (PN).

EVIDENCE ACQUISITION

A literature review was conducted.

EVIDENCE SYNTHESIS

Surgical renal anatomy fundamentally impacts PN surgery. The renal artery divides into anterior and posterior divisions, from which approximately five segmental terminal arteries originate. The renal veins are not terminal. Variations in the vascular and lymphatic channels are common; thus, concurrent lymphadenectomy is not routinely indicated during PN for cT1 renal masses in the setting of clinically negative lymph nodes. Renal-protocol contrast-enhanced computed tomography or magnetic resonance imaging is used for standard imaging. Anatomy-based nephrometry scoring systems allow standardized academic reporting of tumor characteristics and predict PN outcomes (complications, remnant function, possibly histology). Anatomy-based novel surgical approaches may reduce ischemic time during PN; these include early unclamping, segmental clamping, tumor-specific clamping (zero ischemia), and unclamped PN. Cancer cure after PN relies on complete resection, which can be achieved by thin margins. Post-PN renal function is impacted by kidney quality, remnant quantity, and ischemia type and duration.

CONCLUSIONS

Surgical renal anatomy underpins imaging, nephrometry scoring systems, and vascular control techniques that reduce global renal ischemia and may impact post-PN function. A contemporary ideal PN excises the tumor with a thin negative margin, delicately secures the tumor bed to maximize vascularized remnant parenchyma, and minimizes global ischemia to the renal remnant with minimal complications.

PATIENT SUMMARY

In this report we review renal surgical anatomy. Renal mass imaging allows detailed delineation of the anatomy and vasculature and permits nephrometry scoring, and thus precise, patient-specific surgical planning. Novel off-clamp techniques have been developed that may lead to improved outcomes.

Off-clamp robotic partial nephrectomy: Technique and outcome

Introduction:

Robotic partial nephrectomy (RPN) is a technically challenging procedure. Advanced skills are needed to accomplish tumor resection, hemostasis, and renorrhaphy within short ischemia time in RPN. Off-clamp RPN with zero ischemia may decrease the risk of ischemic reperfusion injury to the kidney. However, the off-clamp technique has been associated with an increased risk of blood loss. The purpose of this study was to evaluate the outcome of our modified off-clamp technique utilized in certain RPN cases.

Patients and Methods:

A total of 81 patients underwent RPN between September 2009 and July 2013 for renal masses. We studied a subgroup of patients who underwent off-clamp RPN with zero ischemia time. The off-clamp technique was utilized for exophytic, nonhilar tumors that have a base of 2 cm or less. We developed a novel technique to avoid ischemia reperfusion renal injury while minimizing blood loss in certain cases of RPN.

Results:

Of the 81 cases of RPN, we reviewed and adopted the off-clamp technique in 34 patients (41.98%). Utilizing off-clamp RPN resulted in an average blood loss of 96.29 ml and 1.56 days (range: 1-3 days) of hospital stay and minimal change in serum creatinine.

Conclusions:

Off-clamp RPN is safe and feasible approach to excise certain kidney tumors. It carries the benefits of RPN and prevents ischemia reperfusion renal injury.

Renal Ischemia and Function After Partial Nephrectomy: A Collaborative Review of the Literature

CONTEXT

Partial nephrectomy (PN) is the current gold standard treatment for small localized renal tumors.; however, the impact of duration and type of intraoperative ischemia on renal function (RF) after PN is a subject of significant debate.

OBJECTIVE

To review the current evidence on the relationship of intraoperative ischemia and RF after PN.

EVIDENCE ACQUISITION

A review of English-language publications on renal ischemia and RF after PN was performed from 2005 to 2014 using the Medline, Embase, and Web of Science databases. Ninety-one articles were selected with the consensus of all authors and analyzed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses criteria.

EVIDENCE SYNTHESIS

The vast majority of reviewed studies were retrospective, nonrandomized observations. Based on the current literature, RF recovery after PN is strongly associated with preoperative RF and the amount of healthy kidney parenchyma preserved. Warm ischemia time (WIT) is modifiable and prolonged warm ischemia is significantly associated with adverse postoperative RF. Available data suggest a benefit of keeping WIT <25min, although the level of evidence to support this threshold is limited. Cold ischemia safely facilitates longer durations of ischemia. Surgical techniques that minimize or avoid global ischemia may be associated with improved RF outcomes.

CONCLUSIONS

Although RF recovery after PN is strongly associated with quality and quantity of preserved kidney, efforts should be made to limit prolonged WIT. Cold ischemia should be preferred when longer ischemia is expected, especially in presence of imperative indications for PN. Additional research with higher levels of evidence is needed to clarify the optimal use of renal ischemia during PN.

PATIENT SUMMARY

In this review of the literature, we looked at predictors of renal function after surgical resection of renal tumors. There is a strong association between the quality and quantity of renal tissue that is preserved after surgery and long-term renal function. The time of interruption of renal blood flow during surgery is an important, modifiable predictor of postoperative renal function.

Improving mitochondrial bioenergetics under ischemic conditions increases warm ischemia tolerance in the kidney

Ischemia time during partial nephrectomy is strongly associated with acute and chronic renal injury. ATP depletion during warm ischemia inhibits ATP-dependent processes, resulting in cell swelling, cytoskeletal breakdown, and cell death. The duration of ischemia tolerated by the kidney depends on the amount of ATP that can be produced with residual substrates and oxygen in the tissue to sustain cell function. We previously reported that the rat can tolerate 30-min ischemia quite well but 45-min ischemia results in acute kidney injury and progressive interstitial fibrosis. Here, we report that pretreatment with SS-20 30 min before warm ischemia in the rat increased ischemia tolerance from 30 to 45 min. Histological examination of kidney tissues revealed that SS-20 reduced cytoskeletal breakdown and cell swelling after 45-min ischemia. Electron microscopy showed that SS-20 reduced mitochondrial matrix swelling and preserved cristae membranes, suggesting that SS-20 enhanced mitochondrial ATP synthesis under ischemic conditions. Studies with isolated kidney mitochondria showed dramatic reduction in state 3 respiration and respiratory control ratio after 45-min ischemia, and this was significantly improved by SS-20 treatment. These results suggest that SS-20 increases efficiency of the electron transport chain and improves coupling of oxidative phosphorylation. SS-20 treatment after ischemia also significantly reduced interstitial fibrosis. These new findings reveal that enhancing mitochondrial bioenergetics may be an important target for improving ischemia tolerance, and SS-20 may serve well for minimizing acute kidney injury and chronic kidney disease following surgical procedures such as partial nephrectomy and transplantation.

Emerging technologies to improve techniques and outcomes of robotic partial nephrectomy: striving toward the pentafecta

The technique of robotic partial nephrectomy continues to evolve, but the goals remain the same. Achievement of pentafecta outcomes is difficult to obtain; however, surgeons should continue to strive for this standard of excellence. The future continues to be bright for patients and surgeons alike in continuing to perform robot-assisted partial nephrectomy.

Perioperative outcomes of robotic partial nephrectomy for intrarenal tumors

INTRODUCTION

Intrarenal tumors pose a unique challenge to surgeons due to the lack of visual cues on the kidney surface. Intraoperative ultrasonography has facilitated the management of these tumors during minimally invasive partial nephrectomy. We sought to evaluate the safety, feasibility, and comparative effectiveness of robot-assisted partial nephrectomy (RPN) in the management of completely intrarenal tumors.

METHODS

Our institutional database was queried for patients undergoing RPN between 2007 and 2013. Patient demographics, tumor characteristics, and perioperative outcomes were compared for patients with intrarenal tumors and tumors with any exophytic component. Patients without available preoperative imaging were excluded from the study.

RESULTS

A total of 297 patients were identified with 30 having completely intrarenal tumors and 267 having some exophytic component. Patient demographics were similar between the two groups. Median tumor size was smaller for the intrarenal group than the exophytic group (2.3 vs 2.7 cm, p=0.015) and nephrometry score was higher for the intrarenal group (9 vs 6, p<0.0001). Tumor characteristics were otherwise similar. Perioperative outcomes were similar between the intrarenal and exophytic groups: estimated blood loss (100 vs 100 mL, p=0.56), operative time (165 vs 162 minutes, p=0.86), warm ischemia time (17 vs 17 minutes, p=0.54), renal cell carcinoma positive surgical margin (0% vs 2.4%, p=0.74), intraoperative complications (0% vs 0.76%, p=0.81), and postoperative complications (6.7% vs 17.6% p=0.76).

CONCLUSIONS

RPN is feasible, safe, and effective in the treatment of select intrarenal kidney tumors with outcomes similar to those of partially exophytic tumors. This is likely facilitated by intraoperative ultrasonography. Completely intrarenal kidney tumors should not be automatically relegated to radical nephrectomy or open surgery.

Can selective arterial clamping with fluorescence imaging preserve kidney function during robotic partial nephrectomy?

OBJECTIVE

To compare renal functional outcomes in robotic partial nephrectomy (RPN) with selective arterial clamping guided by near-infrared fluorescence (NIRF) imaging to a matched cohort of patients who underwent RPN without selective arterial clamping and NIRF imaging.

METHODS

From April 2011 to December 2012, NIRF imaging-enhanced RPN with selective clamping was used in 42 cases. Functional outcomes of successful cases were compared with a cohort of patients, matched by tumor size, preoperative estimated glomerular filtration rate (eGFR), functional kidney status, age, sex, body mass index, and American Society of Anesthesiologists score, who underwent RPN without selective clamping and NIRF imaging.

RESULTS

In matched-pair analysis, selective clamping with NIRF was associated with superior kidney function at discharge, as demonstrated by postoperative eGFR (78.2 vs 68.5 mL/min/1.73 m(2); P = .04), absolute reduction of eGFR (-2.5 vs -14.0 mL/min/1.73 m(2); P <.01), and percent change in eGFR (-1.9% vs -16.8%; P <.01). Similar trends were noted at 3 month follow-up, but these differences became nonsignificant (P[eGFR] = .07; P[absolute reduction of eGFR] = .10; and P[percent change in eGFR] = .07). In the selective clamping group, a total of 4 perioperative complications occurred in 3 patients, all of which were Clavien grade I-III.

CONCLUSION

Use of NIRF imaging was associated with improved short-term renal functional outcomes when compared with RPN without selective arterial clamping and NIRF imaging. With this effect attenuated at later follow-up, randomized prospective studies and long-term assessment of kidney-specific functional outcomes are needed to further assess the benefits of this technology.

Feasibility of quantitative diffuse reflectance spectroscopy for targeted measurement of renal ischemia during laparoscopic partial nephrectomy

Reduction of warm ischemia time during partial nephrectomy (PN) is critical to minimizing ischemic damage and improving postoperative kidney function, while maintaining tumor resection efficacy. Recently, methods for localizing the effects of warm ischemia to the region of the tumor via selective clamping of higher-order segmental artery branches have been shown to have superior outcomes compared with clamping the main renal artery. However, artery identification can prolong operative time and increase the blood loss and reduce the positive effects of selective ischemia. Quantitative diffuse reflectance spectroscopy (DRS) can provide a convenient, real-time means to aid in artery identification during laparoscopic PN. The feasibility of quantitative DRS for real-time longitudinal measurement of tissue perfusion and vascular oxygenation in laparoscopic nephrectomy was investigated in vivo in six Yorkshire swine kidneys (n=three animals ). DRS allowed for rapid identification of ischemic areas after selective vessel occlusion. In addition, the rates of ischemia induction and recovery were compared for main renal artery versus tertiary segmental artery occlusion, and it was found that the tertiary segmental artery occlusion trends toward faster recovery after ischemia, which suggests a potential benefit of selective ischemia. Quantitative DRS could provide a convenient and fast tool for artery identification and evaluation of the depth, spatial extent, and duration of selective tissue ischemia in laparoscopic PN.

Robot-assisted laparoscopic partial nephrectomy: Early single Canadian institution experience

BACKGROUND

Although robot-assisted partial nephrectomy (RALPN) has been increasingly adopted, open procedures continue to be the reference nephron-sparing technique. We describe our initial surgical outcomes of RALPN in our single institution robotic program.

METHODS

Between January 2011 and February 2013, 65 consecutive patients underwent a RALPN by 2 surgeons. Preoperative characteristics, including the R.E.N.A.L. nephrometry score, perioperative parameters, and postoperative course, including renal function, were assessed from a retrospective database. The mean follow-up was 12 months.

RESULTS

The mean age was 60.2 years and the mean tumour size was 3.9 cm. According to the R.E.N.A.L. nephrometry score, the tumours were classified moderately and highly complex tumours in 51% and 18.5% of cases, respectively. Median warm ischemia time (WIT) was 21 minutes. Factors associated with WIT were R.E.N.A.L. nephrometry score, tumour size, complication rates and surgeon experience. No conversion or grade 4 to 5 complications were reported. The mean hospital stay was 3 days. The overall complication rate was 24.6% (re-admission rate 7.7%), and decreased to 12% after 20 cases. After these initial 20 cases, a trifecta rate (no margins, preserved renal function, no complications) of 64.3% was achieved in moderately and highly complex tumours. The mean change in estimated glomerular filtration rate was 6.7 mL/min without severe postoperative renal failure.

INTERPRETATION

RALPN is a safe and feasible procedure with low specific morbidity, even in moderately or highly complex renal masses. The WIT depends on tumour characteristics, mainly determined by the R.E.N.A.L. nephrometry score and is improved by surgeon experience. Longer follow-up is needed to assess the oncologic mid-term safety of the procedure.

Zero ischemia robotic partial nephrectomy: sequential preplaced suture renorrhaphy technique

OBJECTIVE

To describe a robotic partial nephrectomy (PN) technique that eliminates renal global ischemia while decreasing parenchymal bleeding.

METHODS

Before tumor resection, a suture is placed through the parenchyma adjacent to the tumor and deep to the planned edge of resection. The tumor resection is begun between the tumor edge and the preplaced suture and continued along the excision margin until some bleeding is encountered. A second suture is placed into the already excised parenchyma. This is repeated until the mass is completely excised, while suturing the parenchyma simultaneously.

RESULTS

Fourteen patients underwent this technique between April 2008 and January 2013 by a single surgeon. Median age was 66 years and 64.3% (N = 9) were men. Median body mass index (BMI) was 27.5 Kg/m(2). Median radius, endophytic, nearness to collecting system, anterior/posterior, and location (RENAL) nephrometry score was 6.5. Median tumor size excised off clamp was 2.2 cm. Three patients had multiple tumors; 2 having a warm ischemia time (WIT) of 14.5 and 15 minutes. Median estimated blood loss (EBL) was 192.5 mL. Median operative time was 160 minutes. There were no Clavien grade 3 or 4 complications. One patient had a postoperative ileus and 1 patient had a blood transfusion and deep vein thrombosis. One patient had a positive tumor parenchymal margin, but negative excisional bed margin. Median hospital stay was 3 days and median follow-up was 8.4 months.

CONCLUSION

Sequential preplaced suture renorrhaphy technique is a safe and effective technique that may be useful in renal function preservation by limiting or eliminating WIT while aiding in maximizing nephron preservation, especially in those patients with solitary kidneys and multiple tumors.

Kidney function after partial nephrectomy: current thinking

PURPOSE OF REVIEW

With clinical guidelines recommending partial nephrectomy for small renal masses, it is essential to understand the benefits of partial nephrectomy in regards to renal function. Our objective was to review current evidence and highlight emerging issues for partial nephrectomy and renal function.

RECENT FINDINGS

A recent clinical trial of partial and radical nephrectomy found minimal differences in survival or adverse renal sequelae. However, most observational studies and systematic reviews suggest that partial nephrectomy decreases the risks of adverse renal function, in particular, new-onset severe chronic kidney disease, and improves overall survival. Key features associated with long-term renal function include treatment modality (observation, ablation, surgery), ischemia type and duration, amount of healthy renal preservation, and baseline renal function.

SUMMARY

Partial nephrectomy should remain the standard of care for small renal masses, if the renal tumor size and complexity are amenable to such a surgical approach. Efforts to minimize ischemia time are important for long-term renal functional recovery, and hypothermia should be considered if longer warm ischemia times are anticipated (i.e. >25 min). Although the preliminary results of zero ischemia partial nephrectomy are promising, further research is needed to determine if these surgical techniques are safely adaptable in the broader urologic community.

The impact of vascular anastomosis time on early kidney transplant outcomes

Background

Most studies have found cold ischemic time to be an important predictor of delayed graft function in kidney transplantation. Relatively less is known about the warm time associated with vascular anastomosis and early outcomes.

Methods

A retrospective cohort of 298 consecutive solitary deceased donor kidney recipients from January 2006 to August 2012 was analyzed to examine the association between anastomosis time and delayed graft function (need for dialysis) and length of hospital stay.

Results

Delayed graft function (DGF) was observed in 56 patients (18.8%). The median anastomosis time was 30 minutes (interquartile range 24, 45 minutes). Anastomosis time was independently associated with DGF in a multivariable, binary logistic regression analysis (odds Ratio (OR) 1.037 per minute, 95% CI 1.016, 1.057, P = 0.001). An anastomosis time >29 minutes was also associated with a 3.5 fold higher (OR 3.5, 95% CI 1.6, 7.3, P = 0.001) risk of DGF. Median days in hospital was 9 (interquartile range 7, 14 days). Every 5 minutes of longer anastomosis time (0.20 days per minute, 95% CI 0.13, 0.27, P <0.001) was associated with 1 extra day in hospital in a multivariable linear regression model. An anastomosis time >29 minutes was associated with 3.8 (95% CI 1.6, 6.0, P <0.001) more days in hospital.

Conclusion

Anastomosis time may be an underappreciated but modifiable variable in dictating use of hospital resources. The impact of anastomosis time on longer term outcomes deserves further study.

The first assistant sparing technique robot-assisted partial nephrectomy decreases warm ischemia time while maintaining good perioperative outcomes

BACKGROUND AND PURPOSE

Prolonged warm ischemia time (WIT) and operative time (OT) during robot-assisted partial nephrectomy (RAPN) can adversely affect renal function and clinical outcomes. Minimizing the duration of WIT and OT is critical to achieving good results postoperatively. Our standard technique for RAPN has evolved into an intracorporeal preparation (ICP) that minimizes the reliance on the first assistant. The goal of the current study was to analyze outcomes after ICP RAPN compared with those of the standard RAPN.

PATIENTS AND METHODS

A retrospective review of all patients who underwent RAPN was performed, comparing standard vs ICP technique. The ICP approach involves tacking of preprepared sutures along the abdominal sidewall adjacent to the kidney in preparation for hemostasis and renorrhaphy before arterial clamping, the use of robotic Scanlan(®) Reliance, bulldog clamps preplaced near the hilum of the kidney, and "sliding-clip" renorrhaphy. We compared intraoperative (OT, WIT, estimated blood loss [EBL]) and pre/postoperative outcomes (serum creatinine, glomerular filtration rate [GFR], length of stay [LOS]) of RAPN between the ICP and standard approach.

RESULTS

A total of 44 consecutive RAPNs (18 ICP, 26 standard) were performed. Median nephrometry score was 7a, and mean follow-up was 13 months. Mean tumor size was 2.4 cm, and most common stage was T(1a). There was no significant difference between ICP and standard RAPN with regard to nephrometry score and stage. Mean WIT was significantly lower for the ICP vs standard RAPN (19 vs 23 min, P=0.049) as was mean OT (161 vs 204 min, P=0.027). On multivariate analysis, ICP RAPN was an independent predictor of WIT (P=0.02). There was no significant impact on preoperative and postoperative GFR for either approach. EBL and LOS were similar between the two groups.

CONCLUSIONS

The ICP RAPN leads to a significant reduction in WIT and OT while maintaining similar perioperative outcomes compared with the standard approach.