Enhanced computed tomography after partial nephrectomy in early postoperative period to detect asymptomatic renal artery pseudoaneurysm

Microwave Scissors-Based Sutureless Laparoscopic Partial Nephrectomy Versus Conventional Open Partial Nephrectomy in a Porcine Model: Usefulness and Complications

BACKGROUND

This study aimed to compare the benefits and safety of microwave scissors-based sutureless laparoscopic partial nephrectomy (MSLPN) with those of conventional open partial nephrectomy (cOPN).

METHODS

Each kidney in nine pigs underwent MSLPN using microwave scissors (MWS) via transperitoneal laparoscopy or cOPN via retroperitoneal open laparotomy. The kidney's lower and upper poles were resected under temporary hilar-clamping. The renal calyces exposed during renal resections were sealed and transected using MWS in MSLPN and were sutured in cOPN. For MWS, the generator's power output was 60 W. Data on procedure time (PT), ischemic time (IT), blood loss (BL), normal nephron loss (NNL), and extravasation during retrograde pyelogram were compared between the two techniques.

RESULTS

The authors successfully performed 22 MSLPNs and 10 cOPNs. Compared with cOPN, MSLPN was associated with significantly lower PT (median, 9.2 vs 13.0 min; p = 0.026), IT (median, 5.9 vs 9.0 min; p < 0.001), BL (median, 14.4 vs 38.3 mL; p = 0.043), and NNL (median, 7.6 vs 9.4 mm; p = 0.004). However, the extravasation rate was higher in the MSLPN group than in the cOPN group (54.5 % [n = 12] vs 30.0 % [n = 3]), albeit without a significant difference (p = 0.265). Pelvic stenosis occurred in one MSLPN procedure that involved deep lower pole resection near the kidney hilum.

CONCLUSIONS

The study data show that MSLPN can improve intraoperative outcomes while reducing technical demands for selected patients with non-hilar-localized renal tumors. However, renal calyces, if violated, should be additionally sutured to prevent urine leakage.

Comparison of off-clamp microwave scissors-based sutureless partial nephrectomy versus on-clamp conventional partial nephrectomy in a canine model

Objectives

To compare the usefulness and safety of off-clamp microwave scissors-based sutureless partial nephrectomy (MSPN) with on-clamp conventional partial nephrectomy (cPN) in dogs.

Methods

We performed off-clamp MSPN using microwave scissors (MWS) in six dogs, and on-clamp cPN in three dogs, in two-stage experiments. The bilateral kidney upper poles were resected via a midline incision under general anesthesia. After 14 days of follow-up, the lower pole resections were performed. The renal calyces exposed during renal resections were sealed and transected using MWS in off-clamp MSPN and were sutured in on-clamp cPN. In the off-clamp MSPN group, the generator's power output of MWS was set as either 50 W or 60 W for each kidney side. We compared the procedure time (PT), ischemic time (IT), blood loss (BL), and normal nephron loss (NNL) between the two techniques using the Mann-Whitney U-test.

Results

We successfully performed 24 off-clamp MSPNs and 12 on-clamp cPNs. The off-clamp MSPN was significantly superior to on-clamp cPN in avoiding renal ischemia (median IT, 0 min vs. 8.6 min, p < 0.001) and reducing PT (median PT, 5.8 min vs. 11.5 min, p < 0.001) and NNL (median NNL, 5.3 mm vs. 6.0 mm, p = 0.006) with comparable BL (median BL, 20.9 ml vs. 23.2 ml, p = 0.804). No bleeding and major urine leakage were noted during the reoperations.

Conclusions

Off-clamp MSPN outperforms on-clamp cPN in lowering the risks of postoperative renal function impairment in dogs.

Robotic-assisted partial nephrectomy: single-layer cortical renorrhaphy is associated with reduced rate of renal artery pseudoaneurysm compared to double-layer renorrhaphy

The study compares the outcome of patients who underwent single-layer outer cortical renorraphy (SLOCR) and double-layer cortical renorraphy (DLR) in our institution. The retrospective analysis of 181 patients who underwent RAPN was performed. Propensity score matching was accomplished on 67 patients using age, BMI, size, distance from collecting system, hilar location and pathological stage. Intraoperative factors assessed included warm ischemia time, renorraphy time, blood loss and operative duration (Levey et al. in Clin Chem 53:766-772, 2007) Post-operative hospital stay, complications like renal artery pseudoaneurysm (RAP), hemorrhage, urine leak and reduction in eGFR were measured. The 67 patients in SLOCR group were compared with similar number in the DLR group using propensity score matching. Warm ischemia time (P < .001), renorraphy time (P < .001) and symptomatic pseudoaneurysm (RAP) rate (P < .001) were significantly less in SLOCR group. SLOCR is associated with reduced rate of symptomatic post-operative RAP.

Feasibility of interaortocaval clamping for renal artery during robot-assisted right partial nephrectomy: A propensity score-matching analysis

AIM

To evaluate the impact of the interaortocaval clamping technique for the right renal artery on perioperative outcomes of patients who underwent robot-assisted partial nephrectomy (RAPN).

METHODS

This study included 111 consecutive patients with right renal masses undergoing RAPN via the transperitoneal approach. In this series, standard and interaortocaval clamping techniques were defined as those for the right renal artery at the renal hilus and interaortocaval space, respectively. Based on the 3D images reconstructed from CT, interaortocaval clamping was preoperatively selected for patients in whom standard clamping of the main renal artery at the right hilum was judged to be technically difficult due to complicated vascular distribution, such as multiple branches of right renal arteries and veins and/or intertwining of these vessels.

RESULTS

Of 111 patients, 95 and 16 were classified into the standard and interaortocaval clamping groups, respectively, and interaortocaval clamping was uneventfully performed as planned in all 16. After adjusting patient variables by 1:3 propensity score-matching, 33 and 11 patients were included in the respective groups, and there were no significant differences in major clinical characteristics between them, while the incidences of multiple branches of right renal vessels as well as their intertwining beside the right renal hilus were significantly higher in the interaortocaval clamping group. However, no significant difference was noted in any of the perioperative outcomes, including operative time or intraoperative blood loss, between the two groups.

CONCLUSIONS

The interaortocaval clamping technique during RAPN is a feasible procedure with acceptable perioperative outcomes compared with standard hilar clamping, making it possible to more accurately resect renal tumors under clear visualization without unnecessary arterial bleeding from the tumor bed in patients with complex vascular distribution at the right renal hilus; however, special attention should be paid to the considerable individual variability of the interaortocaval anatomy.

Comparison of perioperative outcomes among patients with exophytic, mesophytic, and endophytic renal tumors undergoing robot-assisted partial nephrectomy

OBJECTIVES

It has been well documented that partial nephrectomy for completely endophytic renal tumors is a highly challenging procedure accompanied by several technical difficulties even with the assistance of a robotic surgical system. This study aimed to compare perioperative variables among patients with exophytic, mesophytic, and endophytic renal tumors undergoing robot-assisted partial nephrectomy.

METHODS

This study retrospectively included 265 consecutive patients with localized small renal masses undergoing robot-assisted partial nephrectomy at our institution. In this study, completely endophytic tumor was defined as the mass totally covered by renal healthy parenchyma, and according to the points for the 'E' domain of RENAL nephrometry score based on preoperative computed tomography, subjects were classified into three groups as follows: exophytic, mesophytic, and endophytic tumor groups, and perioperative outcomes among these groups were compared.

RESULTS

Of 265 patients, 127, 112, and 26 were classified into the exophytic, mesophytic, and endophytic tumor groups, respectively. A significantly smaller tumor diameter was observed in the endophytic group than in the other groups (P < 0.001), whereas the RENAL nephrometry score was significantly higher (P < 0.001). In addition, the warm ischemia time in the endophytic tumor group was significantly longer than that in other groups (P = 0.009); however, no significant difference in the trifecta achievement was noted among the three groups.

CONCLUSIONS

This study suggests that robot-assisted partial nephrectomy for patients with completely endophytic tumors can be regarded as a feasible approach without marked impairment of perioperative outcomes; however, further investigation of the long-term functional and oncological outcomes in these patients is required.

Natural history of asymptomatic renal artery pseudoaneurysm after robot-assisted partial nephrectomy

Background

We assessed the natural history of renal artery pseudoaneurysm (RAP) after robot-assisted partial nephrectomy (RAPN).

Methods

From May 2016 to September 2020, 106 patients underwent RAPN for renal tumors at our institution. Among 100 patients, excluding 6 who were ineligible for contrast-enhanced computed tomography (CE-CT), 4 underwent renal artery selective embolization (RAE), of which 2 cases were emergency RAE within 7 days after RAPN and the other 2 were prophylactic RAE 8 or more days after RAPN. In 98 patients examined for the clinical course of asymptomatic RAP managed by surveillance, excluding the 2 who underwent emergency RAE, routine CE-CT was performed at 7 days, 1 month and 3 months after RAPN. Factors influencing the occurrence of RAP among these 98 patients, including the 2 who underwent emergency RAE and excluding the 2 who underwent prophylactic RAE, were analyzed by logistic regression analysis.

Results

Median [interquartile range (IOR), range] observation period, age, radiographic tumor size, and maximum diameter of RAP were 20.8 (23.9, 3.0–57.6) months, 63 (18, 22–84) years, 23 (11, 9–48) mm, and 6.6 (5.2, 3.0–16.0) mm, respectively. CE-CT detected 28 RAPs in 23 (23.0%) of 100 patients by 7 days after RAPN and routine CE-CT detected 25 RAPs in 21 (21.4%) of 98 patients excluding 2 who underwent emergency RAE at 7 days after RAPN. RAP was diagnosed by routine CE-CT in 21 (21.4%), 1 (1.0%), and 0 (0%) patients at 7 days, 1 month, and 3 months after RAPN, respectively. In univariate analysis, age [odds ratio (OR) 0.144: 69–84 vs. 22–56 years old, P=0.0179], R.E.N.A.L [radius (tumor size as maximal diameter), exophytic/endophytic properties of tumor, nearness of tumor deepest portion to collecting system or sinus, anterior/posterior descriptor and location relative to polar line] nephrometry score (OR 1.374, P=0.0382), warm ischemic time (OR 1.085, P=0.0393), and renorrhaphy time (OR 1.055, P=0.0408) were significantly associated with the occurrence of RAP. In multivariate analysis, only age (OR 0.124, P=0.0148) was a significant factor.

Conclusions

Asymptomatic RAP up to 15 mm in diameter resolved spontaneously 3 months after RAPN. Young age (under 56 years) may be a factor in the development of RAP.

Complications of renal interventions: a pictorial review of CT findings

A number of potential vascular and non-vascular complications can arise from surgical, extracorporeal shock wave lithotripsy, radiotherapy and radiological renal interventions, including percutaneous image-guided biopsy and drainage. Computed tomography scan is usually one of the first and most important diagnostic imaging examinations requested when a potential complication is suspected. There are a wide range of common and uncommon potential complications from renal interventions. An understanding of underlying risk factors is important to reduce potential complications from renal intervention. Radiologists play a crucial role in recognising and diagnosing post-renal intervention complications on computed tomography scans, which could significantly improve the patient’s prognosis.

Perioperative outcomes in patients undergoing robot-assisted partial nephrectomy: Comparative assessments between complex and non-complex renal tumors

INTRODUCTION

The aim of this study was to investigate the effects of renal tumor complexity on perioperative outcomes in patients receiving robot-assisted partial nephrectomy (RAPN).

METHODS

This study included 153 consecutive patients with cT1 renal masses undergoing RAPN and analyzed their perioperative outcomes, particularly tumor complexity. In this series, cT1b, completely endophytic, hilar, and cystic tumors were considered complex tumors. Patients with tumors that met at least one of the complex criterion were placed in the complex tumor group; patients with tumors that did not meet any of the complex criteria were placed in the non-complex tumor group.

RESULTS

Of the 153 patients, 54 (35.3%) had complex tumors; specifically, 18 (11.8%) had cT1b tumors, 15 (9.8%) had completely endophytic tumors, 28 (18.3%) had hilar tumors, and 8 (5.2%) had cystic tumors. The non-complex group included 99 patients (64.7%). The complex tumor group had significantly longer warm ischemia and console times than the non-complex tumor group, but there was no significant difference between them in the achievement of the trifecta. Both warm ischemia and console times were significantly correlated with the number of complex factors. Multivariate analyses of complex factors demonstrated that completely endophytic and cT1b tumors were independently associated with warm ischemia time and console time, respectively.

CONCLUSIONS

For patients with complex tumors, RAPN may be a feasible procedure with acceptable perioperative outcomes. However, special attention should be paid to long warm ischemia and console times, particularly in those with completely endophytic and/or cT1b tumors.

Renal Artery Pseudo-aneurysms: Do All of Them Require Endovascular Management?

Purpose: Our study examines the etiological profile, clinical and imaging features of renal artery pseudo aneurysms (RAPs), as well as the efficacy and need for the angioembolization of RAPs in a resource-constrained setting. Materials and Methods: A total of 36 patients with RAPs were included in our study. Initial diagnosis was made by Doppler Ultrasonography (USG) followed by CT renal angiography in all cases. DSA was performed in 28 patients, as eight patients showed spontaneous resolution by thrombosis on immediate pre-procedure Doppler study. Angioembolization with a microcoil was performed for 30 aneurysms in 28 patients. Technical success was confirmed at the end of the procedure by a renal angiogram. To assess clinical success, we followed up with patients (with clinical and Doppler USG) for a period of six months. Results: The most common cause of RAPs in our study was percutaneous nephrolithotomy (PCNL), seen in 21 patients (58.3%), followed by trauma (25%), and partial nephrectomy (11%). All patients presented to us were within 21 days of the etiological event of hematuria or flank pain. USG was able to detect the RAP in 22 cases (61%). CT renal angiography was diagnostic in all patients but failed to demonstrate two additional aneurysms in one patient. RAP size ≤ 4 mm and absence of brisk filling on CT renal angiography was associated with spontaneous resolution in eight patients, probably an indication of the beginning of spontaneous thrombosis. Angioembolization was done using microcoils and showed 100% technical and clinical success. Conclusion: PCNL is the most common etiological factor for RAPs in our setting. Such patients should have a Doppler USG done prior to discharge from the hospital. CT angiographic flow dynamics (delayed peak enhancement) may be helpful in the identification of RAPs with a high probability of subsequent spontaneous resolution. Angiography followed by embolization using microcoils is the most effective and safe treatment for RAPs with no significant loss of renal parenchyma, although cost remains a limiting factor in our setting.

Natural History of Asymptomatic Pseudoaneurysm Soon After Robot-assisted Partial Nephrectomy: Single-center Prospective Study

OBJECTIVE

To prospectively investigate the natural history of asymptomatic pseudoaneurysm after robotic-assisted partial nephrectomy.

METHODS

Robotic-assisted partial nephrectomy was undertaken for 67 patients between July 2014 and July 2018. Patients who could not undergo enhanced CT were excluded, so 60 patients were finally included in the present study. We prospectively investigated the presence of pseudoaneurysm based on early enhanced CT scan on postoperative day 7. According to our treatment policy, patients with symptomatic pseudoaneurysm underwent selective transarterial embolization. Meanwhile, patients with asymptomatic pseudoaneurysm were observed with follow-up CT imaging, regardless of the size of the aneurysm.

RESULTS

Overall incidence of pseudoaneurysm on postoperative day 7 was 18% (11/60 cases). The median size of the pseudoaneurysm was 9 mm (quartile: 6-12 mm). Two patients with symptomatic pseudoaneurysm underwent selective transarterial embolization. Nine patients had asymptomatic pseudoaneurysm; in 8 of these it disappeared without therapeutic intervention. The median period from surgery to confirmed disappearance of the aneurysm was 19 days (quartile 14-32 days). In the remaining 1 patient, small asymptomatic pseudoaneurysm (2 mm) could still be observed even 1 year after surgery.

CONCLUSION

Our study showed high incidence of pseudoaneurysm 1 week after robotic-assisted partial nephrectomy that mostly disappeared without therapeutic intervention. Routine enhanced CT screening and pre-emptive embolization may not be necessary for asymptomatic renal artery pseudoaneurysm.

Clinical factors that influence the occurrence of symptomatic pseudoaneurysms and arteriovenous fistulas after partial nephrectomy: multi-institutional study of renal function outcomes after one year of selective arterial embolization

PURPOSE

Renal artery pseudoaneurysms (RAPs) and arteriovenous fistulas (AVFs) are rare but potentially life-threatening complications after partial nephrectomy (PN). Selective arterial embolization (SAE) is an effective method for controlling RAPs/AVFs. We assessed the clinical factors affecting the occurrence of RAPs/AVFs after PN and the effects of SAE on postsurgical renal function.

MATERIALS AND METHODS

Four hundred ninety-three patients who underwent PN were retrospectively reviewed. They were placed in either the SAE or the non-SAE group. The effects of clinical factors, including R.E.N.A.L. scores, on the occurrence of RAPs/AVFs were analyzed. The influence of SAE on the estimated glomerular filtration rate (eGFR) during the first postoperative year was evaluated.

RESULTS

Thirty-three (6.7%) patients experienced RAPs/AVFs within 8 days of the median interval between PN and SAE. The SAE group had significantly higher R.E.N.A.L. scores, higher N component scores, and higher L component scores (all, p <0.05). In the multivariate analysis, higher N component scores were associated with the occurrence of RAPs/AVFs (Odds ratio: 1.96, p=0.039). In the SAE group, the mean 3-day postembolization eGFR was significantly lower than the mean 3-day postoperative eGFR (p <0.01). This difference in the eGFRs was still present 1 year later.

CONCLUSIONS

Renal tumors located near the renal sinus and collecting system were associated with a higher risk for RAPs/AVFs after PN. Although SAE was an effective method for controlling symptomatic RAPs/AVFs after PN, a procedure-related impairment of renal function after SAE could occur and still be present at the end of the first postoperative year.

Mid-term outcome of transarterial embolization of renal artery pseudoaneurysm and arteriovenous fistula after partial nephrectomy screened by early postoperative contrast-enhanced CT

Purpose

To retrospectively evaluate the mid-term outcome of transarterial embolization (TAE) of renal artery pseudoaneurysm (RAP) including arteriovenous fistula (AVF) after partial nephrectomy screened by early postoperative contrast-enhanced CT (CE-CT).

Materials and methods

Eighty-two patients (7.0%) who underwent TAE after partial nephrectomy were reviewed, from 1166 partial nephrectomies performed over 6 years. In 18 patients (22.0%), TAE was performed emergently on the median postoperative day (POD) seven. In the remaining patients, elective TAE was performed on the median POD six for RAP detected by early postoperative CE-CT or that emerged on follow-up CE-CT.

Results

In one patient (1.2%), TAE was performed twice because one of two RAPs could not be embolized during the first TAE, being successfully embolized at the second TAE after readmission with hematuria. Otherwise, no bleeding recurrence or RAPs were observed during the median 1354 follow-up days. Thus, the primary and secondary success rates of TAE were 98.8% (81 of 82 patients) and 100% (82 of 82 patients), respectively. On angiography, the average number of lesions was 1.7 ± 0.9 and the average RAP size was 12.8 ± 6.0 mm. The shapes of the lesions varied: oval-round 60, oval-round + AVF 36, irregular + AVF 14, AVF 12, irregular 10, disruption 4, and extravasation 3. No major complications were observed. The median inpatient days after TAE were two. No estimated glomerular filtration rate deterioration was observed (64.6 ± 18.6 vs. 64.2 ± 18.4 mL/min/1.73 m², p = 0.902).

Conclusion

TAE is largely effective and safe for treating bleedings or RAPs, including AVFs, after partial nephrectomy, as screened by early postoperative CE-CT.

Selective Trans-arterial Embolization of Iatrogenic Vascular Lesions Did Not Influence the Global Renal Function After Partial Nephrectomy

OBJECTIVE

To evaluate the renal function outcomes after selective trans-arterial embolization (SAE) of iatrogenic vascular lesions (IVL), including pseudoaneurysm and arteriovenous fistula, following partial nephrectomy (PN).

MATERIALS AND METHODS

A multi-institutional study was conducted including consecutive patients who underwent PN between January 2009 and March 2019. Two surgical approaches were used: open and robot-assisted PN. Patients with SAE were identified and matched (1:2) with patients without IVL. The matching criteria were age, gender, Charlson score, creatinine clearance, RENAL score, and tumor size. The primary outcome was the evolution of global renal function at 6-months postoperatively.

RESULTS

A total of 493 consecutive PN (360 open PN and 133 robot-assisted PN) were included. IVL occurred in 17 cases (3.4%) without statistical difference according to the surgical approach (P = .78). Patients from embolization group were matched to 34 cases without postoperative IVL. Groups were comparable concerning clinical, tumor and surgical characteristics. The clinical success of SAE, defined as the absence of recourse to a second embolization or a total nephrectomy, was obtained in 16 (94.1%) cases. No minor or major complications were reported after SAE. The preoperative estimated glomerular filtration rate (eGFR) was similar between control group (93 [85-102] ml/min) and embolization group (95 [83-102] ml/min) (P = .99). Median (IQR) eGFR between control group (87 [72-95] ml/min) and embolization group (83 [76-93] ml/min) at a follow-up of 6 months showed no significant difference (P = .73).

CONCLUSION

IVL are rare complications of PN. SAE is an effective and minimally invasive management tool, with no deleterious effect on global renal function.

Significant impact of three-dimensional volumetry of perinephric fat on the console time during robot-assisted partial nephrectomy

Background

To assess the impact of volumetry of perinephric fat (PNF) on the perioperative outcomes of robot-assisted partial nephrectomy (RAPN).

Methods

Between 2016 and 2019, a single surgeon performed RAPN for 128 patients with clinical T1a-b renal tumors at our institution, and the 70 most recent patients were included in this study to minimize the effects of surgical experience. PNF was defined as a fatty area around the kidney within the anatomical structures, including the lateroconal fascia, fusion fascia, psoas muscle, lumbar quadrate muscle and diaphragm, and its volume was calculated based on reconstructed three-dimensional computed tomography images using the SYNAPSE VINCENT system.

Results

In this series, the trifecta and MIC (margin, ischemia and complications) score system outcomes were achieved in 69 (98.6%) and 64 patients (91.4%), respectively. The median PNF volume in the 70 patients was 166.05 cm³, which was significantly correlated with both the body mass index (BMI) and Mayo adhesive probability (MAP) score (correlation coefficient = 0.68 and 0.74, respectively). There was no significant difference in the R.E.N.A.L. nephrometry score, PNF volume or console time during RAPN among 5 groups consisting of 14 consecutive patients. Of several factors examined, the console time was significantly affected by the sex, MAP score and PNF volume, and only the PNF volume was independently associated with the console time.

Conclusion

Even if performed by an experienced robotic surgeon beyond the initial learning curve, the PNF volume may influence the console time during RAPN.

The efficacy of the TachoSil binding suturing technique in laparoscopic partial nephrectomy to prevent the development of pseudoaneurysm

OBJECTIVE

Our specific aim was to introduce the TachoSil binding suturing technique for renal cell carcinoma (RCC) patients when closing the parenchymal defect after tumor excision during laparoscopic partial nephrectomy (LPN), which is a novel technique for reducing the risk of developing subsequent pseudoaneurysm (PA).

METHODS

We identified 113 pT1aN0M0 RCC patients who underwent LPN at our institution. Eighty-one (72%) patients underwent the suturing procedure without binding TachoSil, whereas 32 (28%) patients underwent renorraphy with the renal defect closed together with TachoSil. The vascular complications were evaluated by computed tomography or magnetic resonance imaging with enhanced contrast material at the first visit after LPN. We conducted Fischer's exact test to determine risk factors for transcatheter arterial embolization (TAE).

RESULTS

The median age was 55 (36-86) years old and the median follow-up time was 65 (12-147) months. In the overall population, there were 11 (11%) patients who underwent TAE because they developed PA. All 11 patients exhibited the imaging findings of PA, and were all from the conventional suturing group. In contrast, no patients for whom the TachoSil binding method was used had any significant findings on imaging (14% vs. 0%). Based on the analysis to determine risk factors for TAE due to PA development, the TachoSil binding suturing technique was one of the significant indicators for reducing the risk of developing PA.

CONCLUSIONS

Our study demonstrated that the TachoSil binding suturing technique might reduce the development of PA after LPN. Prospective randomized study and comparison to the standard 2 or 3-layer renorrhaphy is needed to prove its actual value.

Absence of asymptomatic unruptured renal artery pseudoaneurysm on contrast-enhanced computed tomography after robot-assisted partial nephrectomy without parenchymal renorrhaphy

Objective

To assess the incidence of asymptomatic unruptured renal artery pseudoaneurysm (RAP) on contrast-enhanced computed tomography (CE-CT) after robot-assisted partial nephrectomy (RAPN) without parenchymal renorrhaphy.

Methods

From May 2016 to December 2017, 78 patients underwent RAPN for renal tumors. Inner suture was performed in the opened collecting system or renal sinus, whereas parenchymal renorrhaphy was not. For hemostasis, the soft coagulation system was used, and absorbable hemostats were placed on the resection bed. CE-CT was carried out within 7 days after surgery. Data on these patients were prospectively collected. A single radiologist determined the diagnosis of RAP.

Results

Median (range) data were as follows: Patient age, 65 (19–82) years; radiographic tumor size, 30 (12–95) mm; operating time, 166 (102–294) min; warm ischemic time, 16 (7–67) min; and blood loss, 15 (0–4450) mL. One patient (1.6%) required a perioperative blood transfusion. No patient required conversion to open surgery or nephrectomy. CE-CT was carried out at median 6 (3–7) days after surgery. CE-CT showed no RAP development in all 61 patients. Urinary leakage was not observed. One patient had acute cholecystitis, a postoperative complication classified as Clavien-Dindo grade higher than 3, which was treated with cholecystectomy. Positive surgical margin was identified in four patients (6.6%).

Conclusion

RAPN using soft coagulation and absorbable hemostats without renorrhaphy appears to be feasible and safe. Our technique could eliminate the risk of RAP.

Postoperative Complications After Robotic Partial Nephrectomy

Objectives: To assess the incidence of postoperative arterial malformation (AM) and urine leak/urinoma (UL) after robotic partial nephrectomy (RPN) in a contemporary series and to evaluate risk factors for these complications. Materials and Methods: All RPNs were queried from Institutional Review Board-approved retrospective and prospective nephrectomy databases. Demographics, perioperative variables, and postoperative complications were collected. Differences between cohorts were analyzed using univariate analysis. Postoperative complications were graded using the Clavien-Dindo system. UL was defined in the context of signs and symptoms of a collection with supporting evidence of urine collection through drainage or aspiration. AM was identified based on postoperative imaging indicative of arteriovenous fistula or pseudoaneurysm and/or requirement for selective embolization. Predictors of AM and UL were assessed by univariate analysis. Results: A total of 395 RPNs were performed by four urologists between January 2014 and October 2018. Tumor complexity, defined by nephrometry score, was significantly greater in the prospective cohort (p = 0.01). Overall incidence of postoperative complications was 5.6% with cohort-specific incidences of 5.3% and 5.8%. The retrospective cohort had a greater percentage of complications classified as ≥IIIa: 8/13 (61.5%) vs 2/8 (25%). Overall incidence of AM was 2.3% with cohort-specific incidence of 3.1% (7/225) vs 1.1% (2/170). Overall incidence of UL was 0.25% with cohort-specific incidence of 0.55% (1/225) and 0.0% (0/170). The difference in incidence of both complications between cohorts was significant (p < 0.05). No significant predictors for AM were identified. Conclusions: The incidence of postoperative complications after RPN remains low (5.3% vs 5.8%, overall: 5.6%). UL and AM are becoming rarer with experience, despite increasing surgical complexity (0.55% vs 0%, 3.1% vs 1.1%).

Selective transarterial embolization of acute renal hemorrhage: a retrospective study

Introduction: Selective transarterial embolization (STAE) is a minimally invasive treatment method developed as am alternative to surgery for acute renal haemorrhage (ARH). The aim of this study was to evaluate the efficacy and outcome of STAE in ARH patients.Material and methods: The data of patients who underwent STAE with signs of ARH were collected retrospectively. The etiology of renal haemorrhage, localization and type of lesion, embolizing agent used, the amount of contrast material given, duration of fluoroscopy and perioperative and postoperative complications were recorded. Lesions were classified as pseudoaneurysm (PA), arteriovenous fistula (AVF), arterio pelvic fistula (ACF), pathological tumoral vasculature and extravasation.Results: A total of 51 patients were included in the study. The most common symptom was gross hematuria (76.4%) and the most common underlying cause was iatrogenic renal injury (64.7%). Embolizing agents used were n-BCA-iodized oil in 29 patients, coils alone in six patients, coils + n-BCA in four patients, ethanol-iodized oil in three patients, combination of n-BCA-iodized oil and ethanol-iodized oil in two patients, polyvinyl alcohol particles in three patients and covered stent in one patient. Technical success was 100% in all patients and there was no need for reintervention.Conclusions: STAE is a safe, effective and minimally invasive method in emergency treatment of ARH.

Improved perioperative outcomes by early unclamping prior to renorrhaphy compared with conventional clamping during robot-assisted partial nephrectomy: a propensity score matching analysis

The objective of this study was to evaluate the impact of the early unclamping (EU) technique on perioperative outcomes in patients who underwent robot-assisted partial nephrectomy (RAPN). This study included 96 patients with small renal masses who underwent RAPN performed by a single surgeon using the da Vinci Xi between April 2016 and September 2018. EU and conventional clamping (CC) procedures were defined as those removing the renal artery clamp before and after renorrhaphy, respectively. In this series, contrast-enhanced computed tomography was performed 3-5 days after RAPN to examine the incidence of renal artery pseudoaneurysm (RAP). After adjusting patient variables by 1:1 propensity score matching, 45 patients were included in both the EU and CC groups, and no significant differences in major clinical characteristics were noted between these two groups. Although there was no significant difference in the proportion of patients achieving trifecta or the margin, ischemia and complications score between the two groups, the EU group was significantly superior to the CC group regarding the operative time, console time, warm ischemia time, impairment of renal function 1 day after RAPN, incidence of RAP and postoperative length of hospital stay. Furthermore, RAP occurred in seven patients in the entire cohort (13.3%) receiving CC, including two who required trans-arterial embolization due to severe macrohematuria, whereas RAP was completely prevented by the use of EU. The introduction of the EU technique to RAPN may improve perioperative outcomes, particularly by markedly reducing the risk of RAP even with renorrhaphy.

[AN EXPERIENCE OF PARTIAL NEPHRECTOMY IN A PATIENT WITH VON WILLEBRAND DISEASE]

A 28-year-old male visited a nearby hospital with chief complaint of bilateral back pain and fever. He was diagnosed with a right complex renal cyst (Bosniak classification, IIF) with a kidney stone and was referred to our hospital. We first suspected an incarcerated kidney stone and performed flexible transurethral lithotomy; however, his symptoms did not improve. Blood examination revealed prolonged APTT; subsequently, he was diagnosed with von Willebrand disease (VWD). Because he experienced pain due to the hemorrhagic renal cyst, we performed partial nephrectomy. Preoperatively, we supplemented the von Willebrand factor (VWF) based on the VWF activity in the patient. Although intraoperative bleeding was well controlled, he developed bleeding from pseudoaneurysms on the postoperative day (POD) 6. We immediately performed transarterial embolization along with VWF replenishment. VWF supplementation was discontinued on POD 14, and the patient was discharged on POD 23. Since then, he has not experienced a bleeding recurrence or pain. In patients with VWD, the perioperative administration of desmopressin or VWF is recommended. Although several reports showed that surgeries involving these treatments are safe, only three cases with VWD, including the present case where the patient underwent partial nephrectomy, have been reported. In the present case, postoperative bleeding occurred despite exhibiting adequate perioperative VWF activity. Thus, bleeding complications in patients with VWD undergoing partial nephrectomy must be considered and should be carefully followed up.

Comparison of perioperative outcomes with or without renorrhaphy during open partial nephrectomy: A propensity score-matched analysis

Purpose:

Renorrhaphy in partial nephrectomy may damage intraparenchymal vessels and compress the renal parenchyma, which may lead to the formation of renal artery pseudoaneurysms or vascularized parenchymal volume reduction. Using propensity score matching, we compared surgical outcomes following non-renorrhaphy and renorrhaphy techniques for open partial nephrectomy (OPN) for T1a renal tumors.

Materials and Methods:

We retrospectively analyzed data from 159 patients with normal contralateral kidneys who underwent OPN for T1a renal tumors and pre- and postoperative enhanced computed tomography between 2012 and 2015. Patient variables were adjusted using 1:1 propensity score matching between the two Groups: renorrhaphy (inner and outer layer sutures) and non-renorrhaphy (inner layer sutures only). Postoperative complications and renal function were compared between the two groups.

Results:

We matched 43 patients per Group. Operative time, estimated blood loss, cold ischemic time, and postoperative hospital stay were not significantly different between the two Groups. Urine leakage (Clavien-Dindo grade ≥3) occurred in 0 renorrhaphy cases and 2 non-renorrhaphy cases (0% versus 4.6%, P=0.49). Renal artery pseudoaneurysm (RAP) occurred in 6 renorrhaphy cases and in 0 non-renorrhaphy cases (13% versus 0%, P=0.02).

Conclusions:

The non-renorrhaphy technique may result in a lower risk of RAP but a greater risk of urine leakage. This technique needs further refinement to become a standard procedure for OPN.

Prospective study of robotic partial nephrectomy for renal cancer in Japan: Comparison with a historical control undergoing laparoscopic partial nephrectomy

OBJECTIVES

To evaluate the outcomes of robotic partial nephrectomy compared with those of laparoscopic partial nephrectomy for T1 renal tumors in Japanese centers.

METHODS

Patients with a T1 renal tumor who underwent robotic partial nephrectomy were eligible for inclusion in the present study. The primary end-point consisted of three components: a negative surgical margin, no conversion to open or laparoscopic surgery and a warm ischemia time ≤25 min. We compared data from these patients with the data from a retrospective study of laparoscopic partial nephrectomy carried out in Japan.

RESULTS

A total of 108 patients were registered in the present study; 105 underwent robotic partial nephrectomy. The proportion of patients who met the primary end-point was 91.3% (95% confidence interval 84.1-95.9%), which was significantly higher than 23.3% in the historical data. Major complications were seen in 19 patients (18.1%). The mean change in the estimated glomerular filtration rate in the operated kidney, 180 days postoperatively, was -10.8 mL/min/1.73 m² (95% confidence interval -12.3-9.4%).

CONCLUSIONS

Robotic partial nephrectomy for patients with a T1 renal tumor is a safe, feasible and more effective operative method compared with laparoscopic partial nephrectomy. It can be anticipated that robotic partial nephrectomy will become more widely used in Japan in the future.

Endovascular treatment of visceral artery aneurysms and pseudoaneurysms with stent-graft: Analysis of immediate and long-term results

INTRODUCTION

The aim of this study is to analyze the safety and efficacy of stent-graft endovascular treatment for visceral artery aneurysms and pseudoaneurysms.

METHODS

Multicentric retrospective series of patients with visceral aneurysms and pseudoaneurysms treated by means of stent graft. The following variables were analyzed: Age, sex, type of lesion (aneurysms/pseudoaneurysms), localization, rate of success, intraprocedural and long term complication rate (SIR classification). Follow-up was performed under clinical and radiological assessment.

RESULTS

Twenty-five patients (16 men), with a mean age of 59 (range 27-79), were treated. The indication was aneurysm in 19 patients and pseudoaneurysms in 6. The localizations were: splenic artery (12), hepatic artery (5), renal artery (4), celiac trunk (3) and gastroduodenal artery (1). Successful treatment rate was 96% (24/25 patients). Intraprocedural complication rate was 12% (4% major; 8% minor). Complete occlusion was demonstrated during follow up (mean 33 months, range 6-72) in the 24 patients with technical success. Two stent migrations (2/24; 8%) and 4stent thrombosis (4/24; 16%) were detected. Mortality rate was 0%.

CONCLUSION

In our study, stent-graft endovascular treatment of visceral aneurysmns and pseudoaneurysms has demonstrated to be safe and is effective in the long-term in both elective and emergent cases, with a high rate of successful treatment and a low complication rate.

Current status of robotic partial nephrectomy in Japan

The safety and efficacy of robot-assisted partial nephrectomy (RAPN) has been reported in Western countries. However, there are no similar reported studies of RAPN in Japan. Although common medical services are covered by public health insurance in Japan, RAPN had not been approved as a listed treatment for public insurance. We conducted a prospective clinical trial to confirm the efficacy and safety of RAPN in Japan. The aim of the present review article is to describe current status of RAPN in Japan and to introduce a part of clinical results obtained from the clinical trial. Based on the favorable results obtained in this clinical trial, RAPN was approved in April 2016 by the Japanese Ministry of Health, Labour and Welfare to be covered by public health insurance. This change allows access to RAPN to everyone in Japan, regardless of wealth. The RAPN techniques used in Japan are also reviewed.

Open Partial Nephrectomy for High-Risk Renal Masses Is Associated with Renal Pseudoaneurysms: Assessment of a Severe Procedure-Related Complication

Objectives. A symptomatic renal pseudoaneurysm (RPA) is a severe complication after open partial nephrectomy (OPN). The aim of our study was to assess incidence and risk factors for RPA formation. Furthermore, we present our management strategy. Patients and Methods. Clinical records of consecutive patients undergoing OPN were assessed for surgical outcome and postoperative complications. Renal masses were risk stratified for tumor complexity according to the PADUA score. Uni- and multivariate analysis for symptomatic RPAs were performed using the t-tests and logistic regression. Results. We identified 233 patients treated with OPN. Symptomatic RPAs were observed in 13 (5.6%) patients, on average 14 (4–42) days after surgery. Uni- and multivariate analysis identified tumor complexity to be an independent predictor for symptomatic RPAs (p = 0.004). There was a significant correlation between RPAs and transfusion and the duration of stay (p < 0.001 and p = 0.021). Symptomatic RPAs were diagnosed with CT scans and successfully treated with arterial embolization. Discussion. Symptomatic RPAs are not uncommon after OPN for high-risk renal masses. A high nephrometry score is a predictor for this severe complication and may enable a risk-stratified followup. RPAs can successfully be located by CT angiography, which enables targeted angiographic treatment.

Early unclamping might reduce the risk of renal artery pseudoaneurysm after robot-assisted laparoscopic partial nephrectomy

OBJECTIVES

To determine the influence of the early unclamping technique on the risk of renal artery pseudoaneurysm during robot-assisted laparoscopic partial nephrectomy.

METHODS

From January 2013 to October 2014, 96 patients underwent robot-assisted laparoscopic partial nephrectomy for renal masses at Tokyo Women's Medical University Hospital, Tokyo, Japan. Computed tomography angiography was carried out 3-4 days after surgery. Early in the series, renal hilum was left unclamped and renorrhaphy was subsequently carried out (conventional unclamping technique). An early unclamping technique has been used since November 2013.

RESULTS

A total of 61 patients underwent robot-assisted laparoscopic partial nephrectomy with early unclamping, and 35 patients underwent robot-assisted laparoscopic partial nephrectomy with conventional unclamping. Ischemia time was significantly shorter in the early unclamping group (16.5 vs. 23.1 min; P < 0.01). The early unclamping group showed a significantly lower incidence of asymptomatic renal artery pseudoaneurysm relative to the conventional unclamping group (11.4% vs. 28.6%; P = 0.03). Multivariate analysis showed that the early unclamping technique was a significant independent factor in reducing the risk of renal artery pseudoaneurysm (hazard ratio 0.27; P = 0.01).

CONCLUSIONS

The present findings suggest that an early unclamping technique might reduce ischemic time and risk of renal artery pseudoaneurysm. The absence of arterial bleeding before renorrhaphy is likely to be a key step in preventing renal artery pseudoaneurysm during robot-assisted laparoscopic partial nephrectomy.

Early postoperative screening by contrast-enhanced CT and prophylactic embolization of detected pseudoaneurysms prevents delayed hemorrhage after partial nephrectomy

PURPOSE

To evaluate retrospectively whether prophylactic embolization of pseudoaneurysms detected on early postoperative screening with computed tomography (CT) after partial nephrectomy can prevent delayed hemorrhage.

MATERIALS AND METHODS

Between January 2012 and May 2014, early postoperative contrast-enhanced CT was performed 3-5 days after partial nephrectomy in 312 patients (group A); CT was not performed in 65 patients (group B) because of renal insufficiency or contrast medium allergy. If pseudoaneurysms were detected on CT in group A, prophylactic embolization was performed. The frequency of delayed hemorrhage occurring more than 3 days after surgery in group A was compared with group B and with 212 patients (group C) who underwent partial nephrectomy between January 2010 and December 2011 without early postoperative CT. Changes in estimated glomerular filtration rate at discharge were compared among the groups.

RESULTS

Prophylactic embolization of pseudoaneurysms was performed in 26 patients (8%) in group A. Frequency of delayed hemorrhage in group A (0.6%) was significantly lower than in groups B (4.6%; P = .038) and C (4.7%; P = .005). No major complications attributable to prophylactic embolization were observed. The decrease in estimated glomerular filtration rate in group A (-2% ± 13%) was smaller than that in group B (-8% ± 13%; P < .001) and not worse than that in group C (-4% ± 14%; P = .108).

CONCLUSIONS

Prophylactic embolization of pseudoaneurysms detected on early postoperative CT can prevent delayed hemorrhage after partial nephrectomy, without major complications.

Renal sinus exposure as an independent factor predicting asymptomatic unruptured pseudoaneurysm formation detected in the early postoperative period after minimally invasive partial nephrectomy

OBJECTIVES

To investigate the incidence of asymptomatic unruptured renal artery pseudoaneurysm detected by 3-D computed tomography arteriography in the early period after minimally invasive partial nephrectomy, including laparoscopic and robotic partial nephrectomy.

METHODS

From February 2012 to November 2013, 101 patients underwent minimally invasive partial nephrectomy for renal masses. Computed tomography arteriography was carried out 3-4 days after surgery; radiologists diagnosed renal artery pseudoaneurysm in a blinded manner. Factors influencing the occurrence of renal artery pseudoaneurysm were analyzed with the logistic regression model.

RESULTS

The incidence of renal artery pseudoaneurysm was unexpectedly high at 21.7% when detected by computed tomography arteriography during the early period after minimally invasive partial nephrectomy. The renal artery pseudoaneurysm group showed a significantly larger tumor size (P = 0.02), significantly higher N component score (P = 0.01) and higher incidence of renal sinus exposure or opening of the collecting system (P < 0.01) compared with the no renal artery pseudoaneurysm group. Although these aforementioned factors were found to be significant by univariate analysis, multivariate analysis showed that renal sinus exposure was the only significant independent predictive factor for occurrence of renal artery pseudoaneurysm. Tumor-related factors, such as the N component of the nephrometry scoring system or tumor size, did not show an independent influence on the occurrence of renal artery pseudoaneurysm.

CONCLUSIONS

The present study shows an unexpectedly high incidence of asymptomatic unruptured renal artery pseudoaneurysm detected by computed tomography arteriography in the early period after minimally invasive partial nephrectomy. Renal sinus exposure is an independent significant factor predicting the occurrence of renal artery pseudoaneurysm. Avoidance of deep excision into the renal sinus could reduce the risk of renal artery pseudoaneurysm.

[Treatment of pseudoaneurysm following partial nephrectomy]

BACKGROUND

Partial nephrectomy (PN) has become the gold standard for the treatment of small tumors confined to the kidney. As result, the number of PN procedures increased during the last years. Subsequently, we have more often to deal with the complications of this surgery. Among these, pseudoaneurysms are rare but potentially life-threatening due to a risk of bleeding. Therefore, pseudoaneurysms have to be treated according to a relevant strategy.

METHODS

We performed a literature review of the cases of pseudoaneurysm after PN was reported as well as a focus on the different treatment strategies and their outcomes.

RESULTS

The incidence of pseudoaneurysm is low, ranging from 0.5% to 4%. Radio-embolization represents the gold standard treatment, used in 98% of the cases reported in the literature, allowing high success rate and rare morbidity. However, in some selected cases, surveillance could be an alternative.