Comparison of clamping strategies in minimally invasive partial nephrectomy for cT1 tumors.

OBJECTIVES: To determine whether artery only (AO) clamping promises any advantage over artery and vein (AV) clamping in patients undergoing partial nephrectomy with minimally invasive surgical techniques. MATERIAL AND METHODS: We retrospectively analyzed the data of 68 partial nephrectomy patients who were treated with minimally invasive techniques (robot-assisted laparoscopic or pure laparoscopic) for solitary, unilateral, cT1 renal masses during the period of 2008-2019 in a single institution. Patients were divided into two groups according to clamping strategy (AO and AV). The two groups were compared to each other in terms of perioperative outcomes and long-term functional results. RESULTS: The mean patient age and median follow-up period were 56.8 ± 10.8 years and 13.5 (9-44.5) months, respectively. Warm ischemia time, estimated blood loss, transfusion rate and length of hospital stay were similar between the two groups, while operative time was significantly higher in the AO clamping group (p = .726, p = .604, p = .675, p = .103, and p = .038, respectively). Patients who underwent AV clamping had a significantly lower estimated glomerular filtration rate (eGFR) and higher chronic kidney disease rates six months postoperatively (p = .001 and p = .044, respectively) and at the last follow-up (p = .020 and p = .048, respectively). The percentage of eGFR change at six months and the last follow-up was higher in the AV clamp group but the difference was not statistically significant (p = .056 and p = .082, respectively). CONCLUSIONS: Our findings suggest AO clamping is safe and comparable to AV clamping. In our study, AO clamping was found to be superior to AV in terms of long-term eGFR preservation.

Comparison of ischaemia-reperfusion-induced acute kidney injury by clamping renal arteries, veins or pedicles in anaesthetized rats.

NEW FINDINGS: What is central question of this study What are the differences between a traditional renal pedicle-clamping model of acute kidney injury and models with occluded renal artery or vein alone in rats? What is main finding and its importance? During renal venous occlusion, transmission of high arterial pressure into renal capillaries is likely to have caused the rupture of their walls and the occurrence of haemorrhagic congestion that led to higher kidney tissue damage and dysfunction than with pedicle and artery clamping. ABSTRACT: Animal models of ischaemic acute kidney injury (AKI) are valuable tools, but their therapeutic outcomes are not usually translated to humans. Ischaemic AKI in murines is mostly induced via renal pedicle clamping, which is different from patients with AKI that is due to renal artery hypoperfusion or vein thrombosis. This study was designed to compare the traditional pedicle-clamping with artery or vein occlusion alone in rat models of bilateral renal ischaemia-reperfusion (BIR). Twenty-eight anaesthetized male Sprague-Dawley rats were divided into four groups, a sham-operation group and groups that underwent 2 h reperfusion following 30 min clamping of renal arteries (BIR-A group), veins (BIR-V group) or pedicles (BIR-P group). The levels of epithelial injury in proximal tubules and thick ascending limb, intratubular casts and vascular congestion as well as renal malondialdehyde were moderately lower in the BIR-A than BIR-P group, while the BIR-V group showed much higher degrees of these damages than both these groups along with massive haemorrhagic congestion. Accordingly, renal blood flow, glomerular filtration, Na+ reabsorption, K+ and urea excretion, free water reabsorption and urine osmolality were lower in the BIR-V group than in the BIR-A and BIR-P groups, while the BIR-P group had slightly worse renal functional disorders than the BIR-A group. It seems that transmission of high arterial pressure into renal microvessels during venous occlusion causes rupture of capillary walls and haemorrhagic congestion, which leads to intensive kidney injury. In conclusion, the differences in renal disturbances induced by artery, vein and pedicle clamping strongly suggest use of a proper experimental model for each type of human ischaemic AKI.

Retroperitoneal laparoscopic partial nephrectomy with segmental renal artery clamping for cancer of the left upper calyx: a case report.

BACKGROUND: Currently, the standard treatment for renal pelvis carcinoma is radical nephroureterectomy with bladder cuff excision. To describe the feasibility of retroperitoneal laparoscopic partial nephrectomy with segmental renal artery clamping for cancer of renal pelvis, we report this special case for the first time. CASE PRESENTATION: A 67-year-old woman received this operation. Preoperative ureteroscopy revealed a papillary neoplasm with a pedicle in the upper calyx of the left kidney. After entering the retroperitoneal space and dissociating the renal artery and renal vein, the target artery was clamped beyond the final bifurcation before entering the parenchyma. After incision of the left renal parenchyma and exposure of the upper calyceal neck, the tumor was found confined to the upper calyx. Thereafter, the renal calyx and parenchyma were sutured successively after complete resection of the neoplasm. Postoperative pathological examination confirmed that the Grade I papillary carcinoma was confined to the mucosal layer. Thus far, there is no evidence of recurrence during the follow-up period for more than 42 months after surgery. CONCLUSIONS: Retroperitoneal laparoscopic partial nephrectomy with segmental renal artery clamping of the kidney provides a feasible treatment modality for noninvasive tumors that are limited to the calyx.

Retroperitoneal laparoscopic partial nephrectomy with selective renal artery clamping for renal cell carcinoma: initial outcomes.

Introduction: To explore the feasibility and safety of retroperitoneal laparoscopic partial nephrectomy (RLPN) with selective artery clamp (SAC) in patients with renal cell carcinoma (RCC). Methods: The authors recruited three men and two women who underwent RLPN for T1 RCC between December 2022 and May 2023 at a tertiary hospital. The median age of the patients was 32 years (range, 25-70 years). The tumour size ranged from 3 to 4.5 cm. The R.E.N.A.L scores were 4x, 5p, 8a, 5a, and 8ah. The median preoperative eGFR was 96.9 (74.3-105.2). Renal computed tomography angiography was performed before the surgery to evaluate the artery branches. The operation time, number of clamped arteries, warm ischaemic time (WIT), intraoperative blood loss, RCC type, postoperative hospital stay, changes in renal function, and complications were evaluated. The follow-up duration was 6 months. Results: The median operation time was 120 (75-150) minutes. One artery was clamped in four patients, while three were clamped in one patient. The median WIT was 22 (15-30) min, and the median blood loss was 150 (100-300) ml. No complications were recorded, and the resection margin was negative in all patients. The median decrease in eGFR was 6 (4-30%). Conclusions: RLPN with SAC for T1 RCC is safe and feasible in clinical practice.

Renal Functional and Perioperative Outcomes of Retroperitoneal Robot-Assisted Versus Laparoscopic Partial Nephrectomy with Segmental Renal Artery Clamping.

Background: Retroperitoneal approach and segmental renal artery clamping in partial nephrectomy are techniques that facilitate postoperative recovery and renal function preservation. This study aimed to compare the renal function preservation and perioperative outcomes of robot-assisted partial nephrectomy (RAPN) and laparoscopic partial nephrectomy (LPN) with these techniques. Materials and Methods: Clinical parameters of 43 patients who had undergone retroperitoneal RAPN from March 2017 to December 2019 were retrospectively collected and compared with those of 52 patients who had undergone retroperitoneal LPN at the same period in our institution. Differences in operating time, warm ischemia time, estimated blood loss, complications, postoperative hospital stay, as well as renal function loss were compared between the two groups. Results: Background characteristics between RAPN and LPN groups such as age, gender, BMI, and tumor characteristics were comparable. All RAPNs and LPNs were successfully completed without conversion to open surgery or nephrectomy. No significant difference in operating time, estimated blood loss, complications, and postoperative hospital stay was observed between RAPN and LPN groups. The warm ischemia time in RAPN group was slightly shorter than that of LPN groups (P = .054). Compared with the LPN group, the RAPN group was significantly associated with less glomerular filtration rate reduction and renal volume loss rate (P = .042 and P = .013, respectively). Conclusions: The perioperative outcomes were comparable between the two groups. However, compared with LPN, RAPN had superiority in preserving renal function in our series.

Comparison of Renal Artery vs Renal Artery-Vein Clamping During Partial Nephrectomy: A System Review and Meta-Analysis.

Background: Although artery-only (AO) clamping has been proposed to minimize ischemic renal damage compared with artery-vein (AV) clamping, the benefit of AO clamping during laparoscopic partial nephrectomy (LPN) is still controversial. We performed a systematic review and meta-analysis to test the difference between AO clamping and AV clamping in partial nephrectomy (PN). Materials and Methods: A systematic review of the literature on PubMed, Web of Science, the Cochrane Library, and Embase was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement to search-related studies. Data were extracted using a reporting checklist proposed by the Meta-analysis of Observational Studies in Epidemiology Group. RevMan 5.3 software and Stata 12.0 were used to do meta-analysis. Results: The present meta-analysis included 2 retrospective and 3 prospective studies, including 242 patients who underwent AO clamping and 369 patients who underwent AV clamping, which compared AO and AV clamping in LPN for renal cell carcinoma. At baseline, no statistically significant differences were detected between AO and AV clamping groups in terms of body mass index (p = 0.23), tumor size (p = 0.95), but AO clamping group had significantly lower RENAL Score (fixed effects [FE]: weighted mean difference [WMD]: 0.36, p = 0.007). For surgical outcomes analysis, no significant difference was detected regarding to warm ischemia (p = 0.58), operating time (p = 0.40), transfusion rate (p = 0.58), and estimated blood loss (p = 0.35) between two groups. The assessment of renal function by creatinine value both at the early postoperative (p = 0.36) and at last follow-up (p = 0.38) revealed no difference. There was no significant difference in estimated glomerular filtration rate (eGFR) (p = 0.62), and at the early postoperative percentage decrease of eGFR (p = 0.79). However, a higher percentage decrease of eGFR decrease at last follow-up was demonstrated for the AV clamping group (FE: WMD: 2.42, p < 0.00001). Conclusion: These results suggest that AO clamping might be a better choice for PN in long term. Randomized controlled trial studies with larger sample numbers and long-term follow-up and split renal function assessment should be conducted in the future to confirm our conclusion.

A comparative analysis of robotic partial nephrectomy with selective versus main artery clamping in the management of early-stage kidney cancer / 中华泌尿外科杂志

Objective To compare the clinical outcomes of selective artery (SAC) with main artery (MAC) clamping of robotic partial nephrectomy (RPN) in patients with early-stage (cTiN0M0) renal masses.Methods Between October 2016 and September 2018,a total of 343 cT1 renal mass patients receiving RPN with SAC (n =21) or MAC (n =322) in our center,were retrospectively analyzed.There were 13 males and 8 females in SAC group with a mean age of (53.1 ± 10.6) years old,mean tumor size of (2.5 ±0.7)cm,and mean R.E.N.A.L.score of 6.2 ± 1.5.There were 149 males and 173 females in MAC group,with a mean age of (51.6 ± 12.3) years old,mean tumor size of(3.5 ± 1.4)cm,and mean R.E.N.A.L.score of 7.9 ± 1.6.There was statistical significance between two groups in tumor size and R.E.N.A.L score(P ＜ 0.001).The group covariates were balanced through propensity score matching (PSM) using 1:2 nearest neighbor matching method.After matching,mean age,tumor size,R.E.N.A.L.score and preoperative eGFR in the SAC and MAC groups were (3.1 ± 10.6) vs.(52.7 ± 10.2) years,(2.5 ± 0.7) vs.(2.6±0.7) cm,6.2 ±1.5 vs.6.2 ±0.9,and (101.7 ± 19.8)vs.(101.6 ±20.3) ml/(min · 1.73m2),respectively (P ＞ 0.05).Perioperative outcomes and follow-up data were compared between the two matched groups.Results There was no significant differences resulted regarding operating time [(127.0 ±54.8)min vs.(130.0 ±49.9) min],blood loss[(166.0 ± 173.5)ml vs.(124.0 ± 101.0)ml],ischemia time [(18.9 ± 6.4) vs.(18.1 ± 5.8) min],hospital stay [(8.7 ± 3.4) d vs.(8.5 ± 2.5) d],incidences of complications (28.6％ vs.19.0％),surgical conversions (0 vs.2.4％),transfusions (4.8％ vs.2.4％) or positive surgical margin(0 vs.0) and malignant pathological outcomes(95.2％ vs.92.9％).The follow-up durations ranged from 3 to 24 months with a mean duration of 9.1 and 12.4 months in SAC and MAC,respectively.At the end of follow-up,the two groups had similar decrease in estimated glomerular filtration rate [(7.5 ± 17.2) ％ vs.(12.1 ± 18.2) ％,P =0.466],but the difference was statistically significant with ECT-GFR both of function reduction in the operated kidney [(21.6 ± 14.6) ％ vs.(38.4 ± 20.7)％,P =0.001] and in two kidneys [(2.5 ±16.4)％ vs.(14.8 ±20.0)％,P =0.002].Conclusions Robotic partial nephrectomy with selective vascular control lead to better postoperative renal function compared with main vascular clamped PN techniques and does not lead to a higher surgical risk following a strict patient selection criteria.

Application of early sequential unclamping method in laparoscopic partial nephrectomy for patients with T1b renal tumor / 中华泌尿外科杂志

Objective To analyze the value of early sequential unclamping method in laparoscopic partial nephrectomy.Methods From April 2017 to October 2017,a total of 8 cases of renal tumor patients by early sequential unclamping method of laparoscopic partial nephrectomy (LPN) were reviewed,with 5 males and 3 females and average age of 56.4 years (43-70 years).Three cases of renal tumor were located on the left side,5 cases on the right side.The mean tumor diameter was 5.6 (4.6-6.4) cm.The preoperativeR.E.N.A.L.score was 8.8 (7-10),and the mean ASA score was 1.4 (1-2).Preoperative serum creatinine level was 89.5 (72.1-104.2) μmol/L,and the GFR level of the kidney with tumor before operation was 55.5 (40.4-62.3) ml/min.The early sequential unclamping method was used for retroperitoneal laparoscopic partial nephrectomy:according to the preoperative CTA results,the main branches and branches of the renal artery were routinely separated.Before the tumor resection,the branches of renal artery and the main renal artery were sequentially blocked.After removal of the tumor,the first layer of bare kidney wound blood vessels and collection system were sutured and repaired.Then released the main renal artery occlusion clamp,restored most of the blood supply to the kidney,but kept the tumor-specific segmental renal artery blocked.Continuous suture of the kidney created a rough combination of the renal wound.After second layers of suture completed,unclamped the segmental renal artery and sutured the renal wound again,made the third layers of suture intersecting with the second seam suture to strengthen the hemostatic effect.Results All the 8 patients were performed LPN with early sequential unclamping method successfully.The average operative time was 132.5 (90-180) min,the intraoperative blood loss was 142.5 (100-200) ml,the completely warm ischemia time was 15.5 (12.0-20.0) min,and no blood transfusion was performed intraoperatively and postoperatively.The operative margin was negative.The postoperative pathology showed that 7 cases were clear cell carcinoma and 1 cases of papillary cell carcinoma.Postoperative complications such as urinary leakage,incision infection and fever were not found.Drainage tube removal time was 3.5 (3-5) days and the time of postoperative hospitalization was 4.8 (4-6) days.At 1 months after operation,the serum creatinine level was 94.0 (83.6-101.2) μmol/L and the GFR level of one side kidney with tumor was 52.3 (43.2-59.6) ml/min.After 2-9 months of follow-up,there was no recurrence of the tumor.Conclusions Early sequential unclamping method could shorten the warm ischemia time and reduce the risk of bleeding during the operation.It also maintains a clear operative field,which could reduce the difficulty of laparoscopic partial nephrectomy and make a more accurate tumor resection in the complex renal tumor patients.

Differential gene expression profile of miRNAs in mouse models with renal ischemia-reperfusion injury / 器官移植

To screen the differentially-expressed microRNAs (miRNAs) in mouse models with renal ischemia-reperfusion injury (IRI),aiming to offer foundation for unraveling the molecular mechanism of the incidence and progression of IRI.Methods The mouse models with acute IRI were established by renal artery clamping.Fifteen mice were divided into the IRI group and sham surgery group (E group).The animals in the IRI group were subdivided into the A group (45 min ischemia followed by 24 h reperfusion),B group (25 min ischemia followed by 24 h reperfusion),C group (45 min ischemia followed by 4 h reperfusion) and D group (25 min ischemia followed by 4 h reperfusion) (n=3 for each group).The severity ofIRI was evaluated by histological changes and renal function.The differentially-expressed miRNAs in the IRI mouse models at different ischemia time (25 and 45 min) and reperfusion time (4 and 24 h) were screened by using cluster analysis of miRNAs microarray data.The differential expression of miR-695 and miR-145 was validated by quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR).Results Both histological changes and renal function confirmed that the IRI mouse models were successfully established.Compared with the sham surgery group,71 differentially-expressed miRNAs were detected in the IRI group including 30 down-regulated miRNAs and 40 up-regulated miRNAs.The results of qRT-PCR demonstrated that if the standardized expression level of miRNAs in the E group was 1,the relative expression levels of miR-695 and miR-145 were 11.82 and 0.31 in the IRI group (both P＜0.05),which were consistent with the chip results.Conclusions After renal IRI,different changes occur in the gene expression profile of miRNAs.These differentially-expressed miRNAs act as molecular biomarkers for renal IRI with potential clinical and scientific research values.

The study of selective segmental renal artery clamping aggravating pathological injury of the solitary-kidney in a porcine model / 中华泌尿外科杂志

Objective To evaluate the effect of selective segmental renal artery clamping ( SSRAC) on the solitary-kidney, providing a foundamental basis for the using of SSRAC in partial nephrectomy. Methods A total of 18 pigs were randomized equally into 2 groups according to the method of renal artery clamping such as main renal artery clamping ( MRAC) group or SSRAC group.Each case underwent right radical nephrectomy and either MRAC or SSRAC for 60 minutes on the left kidney.Serum creatinine ( SCr) and blood urea nitrogen (BUN) were measured before surgery and at 6 time points thereafter (the 1st, 7th, 14th, 21st, 28th, 90th day).Magnetic resonance imaging was performed before surgery and at 4 time points thereafter (the 1st, 7th, 28th, 90th day) and T2 relaxation time and apparent diffusion coefficient (ADC) were determined.Inflammatory cell infiltration and interstitial fibrosis were detected using renal histology on the 1st and 90th day after operation.Results SCr and BUN of the two groups increased to peak value on the 1st day, and then decreased gradually to normal on the 90th day after the operation.On the 1st day, SCr [(266.43 ±31.12)umol/l] and BUN [(13.63 ±2.54)mmol/l)] of SSRAC group were significantly lower than that of MRAC [(386.37 ±40.40)umol/l,(26.83 ±5.96)mmol/l] (P0.05) on the 7th, 14th, 21st, 28th, 90th day.In the MRAC group, the T2 relaxation time of upper, middle and lower pole of the left kidney increased and the ADC decreased on the 1st day after operation.It arrived to the peak value on the 7th day, and decreased or increased respectively from then on to normal level on the 90th day.In the SSRAC group, there were no significant changes of T2 relaxation time and ADC in the upper and middle pole of left kidney (P>0.05), but it was similar to that in the MRAC group for lower pole.On the 1st, 7th, 28th day after operation, the T2 relaxation time of upper and middle pole of the left kidney in the MRAC group [(45.50 ±1.87),(51.82 ±2.27), and(40.37 ±1.93)ms ) ] were significantly higher than those in the SSRAC group [(36.67 ± 1.33),(35.15 ±1.27), and(37.48 ±1.37)ms](P0.05).On the 1st, 7th, 28th day after operation, the ADC of upper and middle pole of the left kidney in the MRAC group [(2.29 ±0.08) ×10 -3 mm2/s, (2.10 ±0.08) ×10 -3 mm2/s, (2.41 ±0.09) ×10 -3 mm2/s] were significantly lower than that of the SSRAC group [(2.69 ± 0.08) ×10 -3 mm2/s, ( 2.63 ±0.06 ) ×10 -3 mm2/s, ( 2.68 ±0.05 ) ×10 -3 mm2/s ] ( P <0.05 ) . However, on the 1st,7th, 28th, 90th day after operation, the ADC of lower pole of the left kidney in the SSRAC group [(1.93 ±0.08) ×10 -3mm2/s,(1.91 ±0.09) ×10-3mm2/s,(2.33 ±0.07) ×10 -3mm2/s, and (2.43 ±0.07) ×10 -3 mm2/s] were significantly lower than those of the MRAC group [ (2.37 ±0.05) ×10 -3 mm2/s, (2.06 ±0.07) ×10 -3 mm2/s, (2.46 ±0.09) ×10 -3 mm2/s, (2.61 ±0.08) ×10 -3 mm2/s](P<0.05).The whole left kidney in MRAC group experienced extensive tubular hydropic degeneration and limited inflammatory cell infiltration on the 1st day after operation.Moreover, renal tubular hydropic degeneration alleviated and no glomerular changes, fibrous tissue hyperplasia or inflammatory cell infiltration was found on the 90th day after operation.In SSRAC group, no changes were found in upper and middle pole of left kidney at the two time points, while the pathological injury of the lower pole of left kidney was more severe.Conclusions SSRAC has obvious protective effect on renal function in the early stage. However, compared with MRAC, the renal tissue injury in the ischemic area was more serious.Therefore, to protect renal function in partial nephrectomy, the ischemic renal area should be reduced as much as possible, even to zero-ischemic, when adopting SSRAC.