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

Timing, incidence and management of delayed bleeding after partial nephrectomy in patients at risk for recurrent, bilateral, multifocal renal tumors

INTRODUCTION

Delayed bleeding is a potentially serious complication after partial nephrectomy (PN), with reported rates of 1%-2%. Patients with multiple renal tumors, including those with hereditary forms of kidney cancer, are often managed with resection of multiple tumors in a single kidney which may increase the risk of delayed bleeding, though outcomes have not previously been reported specifically in this population. The objective of this study was to evaluate the incidence and timing of delayed bleeding as well as the impact of intervention on renal functional outcomes in a cohort primarily made up of patients at risk for bilateral, multifocal renal tumors.

METHODS

A retrospective review of a prospectively maintained database of patients with known or suspected predisposition to bilateral, multifocal renal tumors who underwent PN from 2003 to 2023 was conducted. Patients who presented with delayed bleeding were identified. Patients with delayed bleeding were compared to those without. Comparative statistics and univariate logistic regression were used to determine potential risk factors for delayed bleeding.

RESULTS

A total of 1256 PN were performed during the study period. Angiographic evidence of pseudoaneurysm, AV fistula and/or extravasation occurred in 24 cases (1.9%). Of these, 21 were symptomatic presenting with gross hematuria in 13 (54.2%), decreasing hemoglobin in 4(16.7%), flank pain in 2(8.3%), and mental status change in 2 (8.3%), while 3 patients were asymptomatic. Median number of resected tumors was 5 (IQR 2-8). All patients underwent angiogram with super-selective embolization. Median time to bleed event was 13.5 days (IQR 7-22). Factors associated with delayed bleeding included open approach (OR 2.2, IQR(1.06-5.46), P = 0.04 and left-sided surgery (OR 4.93, IQR(1.67-14.5), P = 0.004. Selective embolization had little impact on ultimate renal functional outcomes, with a median change of 11% from the baseline eGFR after partial nephrectomy and embolization. One patient required total nephrectomy for refractory bleeding after embolization.

CONCLUSIONS

Delayed bleeding after PN in a cohort of patients with multifocal tumors is an infrequent event, with similar rates to single tumor series. Patients should be counseled regarding timing and symptoms of delayed bleeding and multidisciplinary management with interventional radiology is critical for timely diagnosis and treatment.

Temporal Study of Renal Volume Losses in Patients with Robotic Partial Nephrectomies

Purpose: Robotic partial nephrectomies (RPNs) by their nature are associated with renal volume loss. Our goal of this study is to examine renal volume loss over time post partial nephrectomy. Materials and Methods: Fifty patients were followed for 1-year post-RPN with two-layer renorrhaphy and the sliding clip technique. This was done with a preoperative CT scan to assess renal mass and location. Patients post-RPN were imaged at time points 3 days, 6 months, and 12 months. Results: Patient demographics were 82% men with a median (interquartile range [IQR]) age of 57 (45-67) years and all were of Japanese descent. The medians (IQR) for warm ischemia time were 18 minutes (14-22), total operative time was 181.5 minutes (169.3-218.5), and estimated blood loss was 20 mL (10-50). The tumor characteristics had a median (IQR) diameter of 2.8 cm (2.5-3.4) with a RENAL score of 7 (6-8). The renal CT showed median (IQR) volume losses at 3 days of -1% (-7.1, 1.8), at 6 months of -15.3% (-20.6, -11.2), and at 12 months of -16.3% (-19.0, -12.8). Significance was seen at the 3 days to 6 months comparison for volume loss (p < 0.0001). Mean (standard deviation) estimated glomerular filtration rate (GFR) losses were as follows: at discharge 0.5% (12.9), 1 month -6.4% (11.8), 6 months -4.6% (9.8), and 12 months -3.6% (11.9). Statistical analysis showed significance for GFR loss at the comparison between discharge to 1 and 6 months (p = 0.01, p = 0.04). Conclusion: The initial volume loss seen postsurgery from resected healthy tissue was not significant and only became relevant at longer time points, suggesting that loss could be from atrophy. Volume loss over time supports the hypothesis that suture renorrhaphy is a primary cause of volume loss when warm ischemia time is <25 minutes.

Early dark cortical band sign on CT for differentiating clear cell renal cell carcinoma from fat poor angiomyolipoma and detecting peritumoral pseudocapsule

OBJECTIVES

To retrospectively evaluate whether the early dark cortical band (EDCB) on CT can be a predictor to differentiate clear cell renal cell carcinoma (ccRCC) from fat poor angiomyolipoma (Fp-AML) and to detect peritumoral pseudocapsules in ccRCC.

METHODS

The EDCBs, which are comprised of unenhanced thin lines at the tumor-renal cortex border in the corticomedullary phase, on the CT images of 342 patients who underwent partial nephrectomy were evaluated. Independent predictors among the clinical and CT findings for differentiating ccRCC from Fp-AML were identified using multivariate analyses. The diagnostic performance of the EDCB for diagnosing peritumoral pseudocapsule in ccRCC and differentiating ccRCC from Fp-AML was calculated.

RESULTS

The EDCB was observed in 157 of 254 (61.8%) ccRCCs, 4 of 31 (12.9%) chromophobe RCCs, 1 of 21 (4.8%) papillary RCCs, 3 of 11 (27.3%) clear cell papillary RCCs, 3 of 8 (37.5%) oncocytomas, and 0 of 17 (0%) Fp-AMLs. There was substantial interobserver agreement for the EDCB (k = 0.719). The EDCB was a significant predictor for differentiating ccRCC from Fp-AML (p < 0.001). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value of the EDCB for differentiating ccRCC from Fp-AML were 61.8%, 100%, 100%, and 14.9%, respectively, and those for detecting pseudocapsule in 236 ccRCCs were 62.3%, 68.8%, 96.5%, and 11.7%, respectively.

CONCLUSION

Although diagnostic accuracy of the EDCB for detecting peritumoral pseudocapsule in RCC is inadequate, it can be a predictor for differentiating ccRCC from Fp-AML with high specificity and PPV.

KEY POINTS

• The early dark cortical band (EDCB) sign is observed in nearly two-thirds of clear cell renal cell carcinoma (ccRCC) that are treated by partial nephrectomy and have substantial interobserver agreement. • The EDCB is a significant predictor for differentiating ccRCCs from fat poor angiomyolipomas, with a high specificity and positive predictive value. • Diagnostic accuracy of the EDCB for detecting peritumoral pseudocapsule in ccRCC is inadequate, though better than those in the nephrographic and excretory-phase images.

Detection of a peritumoral pseudocapsule in patients with renal cell carcinoma undergoing robot-assisted partial nephrectomy using enhanced MDCT

To investigate the detection of peritumoral pseudocapsule (PC) using multi-detector row computed tomography (MDCT) for tumors resected by robot-assisted laparoscopic partial nephrectomy (RAPN) for T1 renal cell carcinoma (RCC). Study participants included 206 patients with clinical T1 RCC who underwent RAPN between October 2017 and February 2018. Two radiologists who were blinded to the pathological findings evaluated the computed tomography (CT) images. Radiological diagnosis of a PC was defined by a combination of observations, including a low-attenuation rim between the tumor and renal cortex in the cortico-medullary phase and a high-attenuation rim at the edge of the tumor in the nephrogenic or excretory phase. A PC was detected on CT in 156/206 tumors (76%) and identified by pathology in 182/206 (88%) tumors including 153/166 (92%) clear cell RCC, 13/14 (93%) papillary RCC, and 7/16 (44%) chromophobe RCC. In the whole cohort, CT findings showed a sensitivity of 81.3% (148/182), specificity of 66.7% (16/24), and positive predictive value of 94.9% (148/156). When the data were stratified according to pathological subtypes, MDCT was observed to have a sensitivity of 86.9% (133/153) and specificity of 61.5% (8/13) in clear cell RCC, sensitivity of 38.5% (5/13) and specificity of 100% (1/1) in papillary RCC, and sensitivity of 44.4% (4/7) and specificity of 66.7% (6/9) in chromophobe RCC. A low or high-attenuation rim around the tumor in the cortico-medullary or nephrographic-to-excretory phase indicates a PC of RCC, though the accuracy is not satisfactory even with 64- or 320-detector MDCT.

Clinical efficacy of coil embolization in treating pseudoaneurysm post-Whipple operation

The present study aimed to evaluate the clinical efficacy and safety of angiography and coil embolization for pseudoaneurysm post-pancreatoduodenectomy (PD). A total of 17 patients with gastrointestinal or abdominal hemorrhage after PD were included in the present study. Angiography was performed on the celiac artery, common hepatic artery, splenic artery, gastroduodenal artery and superior mesenteric artery to determine the size of the pseudoaneurysm, the parent artery and its collateral branches. A variety of embolization techniques have been applied to embolize pseudoaneurysm, including the sac packing technique, proximal embolization, exclusion technique and sandwich technique. Different techniques with coils were used for embolization and the clinical effects of embolization were analyzed. A total of 18 pseudoaneurysms were identified in 17 patients. In 2 patients, severe technical complications occurred, including migration of the coil and rupture of pseudoaneurysm, and one of them died, which may have been associated with this complication. No serious clinical complications were observed in the other patients. A total of 7 patients had mild clinical complications, including mild abdominal and dorsal pain, which were alleviated after symptomatic management. A total of 15 patients with definite pseudoaneurysm were successfully embolized without re-bleeding and complications. The clinical success rate was 94.1% (16/17). In conclusion, a variety of embolization techniques may be applied for the treatment of pseudoaneurysm after PD, which have high technical and clinical success rates and small trauma. It is recommended in emergency situations, but care should be taken to avoid serious technical complications.

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.

Image quality of early postoperative CT angiography with reduced contrast material and radiation dose using model-based iterative reconstruction for screening of renal pseudoaneurysms after partial nephrectomy

PURPOSE

To evaluate the image quality of early postoperative CT angiography with low contrast material and radiation dose using model-based iterative reconstruction (FIRST) for screening pseudoaneurysms after partial nephrectomy.

METHODS

CT angiography was obtained before surgery using conventional iterative dose reduction reconstruction (AIDR 3D) with 120 kVp and 600 mgI/kg of contrast material and obtained after partial nephrectomy using FIRST with 80-100 kVp and 360 mgI/kg in 35 patients. Contrast-to-noise ratio, visual image quality scores using a 5-point scale, and longest length of the unaffected renal arteries on maximum intensity projection images were retrospectively compared between FIRST and AIDR 3D.

RESULTS

No significant differences existed in contrast-to-noise ratio or image quality scores of the renal arteries between FIRST and AIDR 3D (25.8 ± 6.6 vs. 25.4 ± 7.0, p = 0.991 and 4.8 ± 0.4 vs. 4.5 ± 0.9, p = 0.515, respectively). Visualization scores and longest length of the peripheral renal arteries in FIRST were significantly superior to those of AIDR 3D (4.3 ± 0.8 vs. 3.5 ± 1.0, p < 0.001 and 100.4 ± 14.9 mm vs. 90.2 ± 15.7 mm, p = 0.010, respectively). The dose-length product with FIRST was significantly lower than that with AIDR 3D (566.1 ± 217.4 mGy.cm vs. 829.8 ± 324.9 mGy.cm, p < 0.001).

CONCLUSION

FIRST can improve visualization of the peripheral renal arteries with contrast material and radiation dose reduced by approximately 30 % compared with AIDR 3D, which enables adequate evaluation of pseudoaneurysms after partial nephrectomy.

Superselective transcatheter arterial embolization to control renal hemorrhage after partial nephrectomy for renal tumors: A report of 9 cases and a literature review

Objective

Materials and methods

Results

Conclusions

Performing an early systematic Doppler-ultrasound fails to prevent hemorrhagic complications after complex partial nephrectomy

Background:

The aim of this work was to assess the clinical relevance of a systematic postoperative Doppler-ultrasound (DU) after complex partial nephrectomy (PN).

Materials and methods:

All patients who underwent open, laparoscopic or robotic PN from 2014 to 2017 at our institution were included. Postoperative hemorrhagic complications (HCs) were defined as the occurrence of blood transfusion, hemorrhagic shock, arterial embolization, or re-hospitalization for hematoma. DU was systematically performed between post-op day 4 and 7 for every complex tumor (RENAL score ⩾ 7). DU was considered positive in the presence of pseudoaneurysm (PA) or arteriovenous fistula (AVF).

Results:

Among 194 patients, 117 underwent DU (60.3%). We reported 22 HCs (11.3%) requiring 8 selective embolization procedures (4.1%). HCs occurred during the hospital stay in 17 patients (77.3%), thus directly diagnosed on a computed tomography scan. Among the five patients (22.7%) with HC occurring after hospital discharge, between day 7 to 15, four had a previously negative systematic DU. Overall, systematic DU was positive in only five patients (4.3%) with only one patient of 194 (0.5%) undergoing preventive embolization of a PA-AVF. The negative predictive values (NPVs) and positive predictive values of DU were respectively 96.5% and 5%, with 20% sensitivity and 96.5% specificity.

Conclusions:

Our results may suggest offering systematic DU in patients under antiplatelet therapies, with high tumor size (>T1b), or early postoperative hemoglobin variations. A high NPV of DU might be counterbalanced by its low sensibility. Since all secondary HCs occurred between postoperative day 7 to 15, our results may suggest differing DU in selected cases.

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.

[Management of traumatic and iatrogenic arterial pseudoaneurysms in a tropical environment]

A false aneurysm or pseudoaneurysm (PA) is the formation of a pulsatile and encapsulated hematoma in communication with the lumen of a perforated artery. Its origin is different but most cases are associated with a traumatic event. Currently, the referenced treatment is endovascular surgery but it is not feasible for the majority of vascular surgeons working in a tropical environment. The aim of this study was to describe the diagnostic and therapeutic aspects of arterial PA (APA) encountered in our institution and to evaluate the place of open surgical technique in their management. This was a 30-month retrospective and descriptive study carried out in our institution (CHU-JRA, Antananarivo, Madagascar). Between 2012 and 2014, ten cases of APA were operated. There were 8 men with an average age of 30 years. The etiologies were accidental trauma (n=6) or iatrogenic vascular injury (n=4). Most patients had a painful and pulsatile swelling (n=8). The presence of a wound scar located on the swelling was observed in 5 patients. The false aneurysms were localized in the radial (n=3), femoral (n=2), brachial (n=2), carotid (n=2) and ulnar (n=1) arteries. The diagnosis was confirmed by ultrasound Doppler in all patients. The treatment was an open surgical procedure and consisted of lateral suture (n=4), resection with direct end-to-end anastomosis (n=1) or using autologous saphenous vein graft (n=2) or ligation (n=3). Postoperative courses and outcomes at last follow-up were uneventful with optimal patency rate.

Clinical results of renal artery embolization to control postoperative hemorrhage after partial nephrectomy

Background

With the wider application of nephron-sparing surgery, there has been an increase in the occurrence of postoperative hemorrhage. However, despite such an increase, there are only a limited number of reports regarding renal artery embolization (RAE) for the management of postoperative bleeding after nephron-sparing surgery, especially after robot-assisted laparoscopic partial nephrectomy (RALPN).

Purpose

To evaluate the safety and clinical efficacy of transcatheter RAE for postoperative hemorrhage after open partial nephrectomy (OPN) and RALPN.

Material and Methods

A total of 29 patients (17 men, 12 women; age range, 31–70 years) who were referred to our hospital for postoperative hemorrhage after partial nephrectomy, between December 2003 and December 2014, were selected. We retrospectively reviewed patients’ clinical data, angiographic findings, embolization details, and clinical outcomes.

Results

Embolization was performed in patients who underwent OPN (25/29) and RALPN (4/29). The angiographic findings were as follows: renal artery pseudoaneurysm (n = 18), contrast extravasation (n = 8), and arteriovenous fistula (n = 3). Fiber-coated microcoil and n-butyl-2-cyanoacrylate (NBCA) was administered to the targeted bleeding renal arteries in 12 and 11 patients, respectively. In six patients, fiber-coated microcoil and NBCA were used concurrently. Technical and clinical successes were achieved in all patients (100%). Bleeding cessation was achieved in all patients, and no further relevant surgeries or interventions were required for hemorrhage control. There were no episodes of hemorrhagic recurrence during the follow-up period (median, 20 days; range, 7–108 days).

Conclusion

Angiography and RAE identified the origin of bleeding and could successfully preserve the residual renal function.

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.