Aaron M. Potretzke

Retroperitoneal Robot-Assisted Partial Nephrectomy for Posterior Renal Masses Is Associated with Earlier Hospital Discharge: A Single-Institution Retrospective Comparison

PURPOSE To compare perioperative outcomes, specifically hospital length of stay (LOS), after retroperitoneal and conventional transperitoneal robot-assisted partial nephrectomy (RAPN). PATIENTS AND METHODS We retrospectively compared consecutive patients with a posterior renal mass undergoing retroperitoneal RAPN (n=116) versus transperitoneal RAPN (n=97) at our institution between July 2007 and March 2014. The surgical approach was based on patient and tumor characteristics, history of abdominal surgery, and surgeon preference. The primary outcome was postoperative LOS, and secondary outcomes included complication rate, inpatient narcotic pain medication use, and inpatient antiemetic use. RESULTS Baseline patient and tumor characteristics were similar between groups. A significantly great proportion of patients undergoing retroperitoneal RAPN had LOS equal to 1 day (57% vs 10%, P<0.01). Complication rates were similar between groups (P=0.37). Median pain medication use was also similar between groups (P=0.85). A significantly greater proportion of retroperitoneal RAPN patients, however, needed no antiemetics postoperatively (59% vs 43%, P=0.02). On multivariate analysis, transperitoneal RAPN was a significant predictor of LOS greater than 1 day (odds ratio=7.4, P<0.01), when controlling for age, sex, body mass index, patient comorbidity, previous abdominal surgery, baseline kidney function, nephrometry score, and tumor size. CONCLUSIONS For patients with posterior renal masses, retroperitoneal RAPN significantly reduces their hospital LOS when compared with transperitoneal RAPN.

Urinary fistula after robot-assisted partial nephrectomy: a multicentre analysis of 1 791 patients.

To evaluate the incidence of and risk factors for a urine leak in a large multicentre, prospective database of robot‐assisted partial nephrectomy (RPN).

Antibody-Based Therapy for Enterococcal Catheter-Associated Urinary Tract Infections

ABSTRACT Gram-positive bacteria in the genus Enterococcus are a frequent cause of catheter-associated urinary tract infection (CAUTI), a disease whose treatment is increasingly challenged by multiantibiotic-resistant strains. We have recently shown that E. faecalis uses the Ebp pilus, a heteropolymeric surface fiber, to bind the host protein fibrinogen as a critical step in CAUTI pathogenesis. Fibrinogen is deposited on catheters due to catheter-induced inflammation and is recognized by the N-terminal domain of EbpA (EbpANTD), the Ebp pilus’s adhesin. In a murine model, vaccination with EbpANTD confers significant protection against CAUTI. Here, we explored the mechanism of protection using passive transfer of immune sera to show that antisera blocking EbpANTD-fibrinogen interactions not only is prophylactic but also can act therapeutically to reduce bacterial titers of an existing infection. Analysis of 55 clinical CAUTI, bloodstream, and gastrointestinal isolates, including E. faecalis, E. faecium, and vancomycin-resistant enterococci (VRE), revealed a diversity of levels of EbpA expression and fibrinogen-binding efficiency in vitro. Strikingly, analysis of 10 strains representative of fibrinogen-binding diversity demonstrated that, irrespective of EbpA levels, EbpANTD antibodies were universally protective. The results indicate that, despite diversity in levels of fibrinogen binding, strategies that target the disruption of EbpANTD-fibrinogen interactions have considerable promise for treatment of CAUTI. IMPORTANCE Urinary catheterization is a routine medical procedure, and it has been estimated that 30 million Foley catheters are used annually in the United States. Importantly, placement of a urinary catheter renders the patient susceptible to developing a catheter-associated urinary tract infection, accounting for 1 million cases per year. Additionally, these infections can lead to serious complications, including bloodstream infection and death. Enterococcus strains are a common cause of these infections, and management of enterococcal infections has been more difficult in recent years due to the development of antibiotic resistance and the ability of strains to disseminate, resulting in a major threat in hospital settings. In this study, we developed an antibiotic-sparing treatment that is effective against diverse enterococcal isolates, including vancomycin-resistant enterococci, during catheter-associated urinary tract infections. Urinary catheterization is a routine medical procedure, and it has been estimated that 30 million Foley catheters are used annually in the United States. Importantly, placement of a urinary catheter renders the patient susceptible to developing a catheter-associated urinary tract infection, accounting for 1 million cases per year. Additionally, these infections can lead to serious complications, including bloodstream infection and death. Enterococcus strains are a common cause of these infections, and management of enterococcal infections has been more difficult in recent years due to the development of antibiotic resistance and the ability of strains to disseminate, resulting in a major threat in hospital settings. In this study, we developed an antibiotic-sparing treatment that is effective against diverse enterococcal isolates, including vancomycin-resistant enterococci, during catheter-associated urinary tract infections.

Laparoscopic Partial Nephrectomy: Rest in Peace

Is robotic partial nephrectomy (RPN) a superior operation to laparoscopic partial nephrectomy (LPN)? In the article by Choi et al [1] in this month’s issue of European Urology, a total of 23 studies with 2240 patients were evaluated and revealed that RPN has numerous superior outcomes compared with LPN. RPN was found to provide a better postoperative estimated glomerular filtration rate, a lower conversion (to open or radical surgery) rate, shorter warm ischemia time, and shorter length of stay. Proponents of LPN will argue that these studies are difficult to examine scientifically because of a lack of standard anatomic scoring (PADUA or RENAL score), a lack of randomization, or unrecognized retrospective biases. Such arguments are certainly valid, but are they ultimately meaningful in the modern surgical context? It is true that identical dissections can be performed laparoscopically and robotically; however, the adjunctive ability of a robotic surgeon to sculpt the excision and efficiently suture the defect is far superior to the laparoscopic approach. The robot allows, for example, sliding-clip renorrhaphy, which provides improved operative times, warm ischemia times, and closing tension [2,3]. Laparoscopic suturing is difficult, inelegant, and imprecise. In contrast, robotic suturing is targeted and exact and can become facile after a relatively short learning curve [4]. Is it possible to test this claim in a controlled, standardized study? To do so, especially in human participants, would be extremely difficult, as each kidney and mass is different. However, if one is to view some of the older laparoscopic videos of partial nephrectomy (PN), a straightforward, intuitive conclusion can be drawn. It is clear that the LPN technique seems suboptimal, except in a historical context. It is also true that several expert laparoscopic surgeons have transitioned their practice to robotic surgery. This includes senior minimally invasive surgeons at our institution (including S.B.B.), and a senior author of the present article (Koon Ho Rha) [1]. Certainly, in reviewing the ‘‘household names’’ of laparoscopic surgery, the literature reports very few who are continuing to perform laparoscopic prostatectomy, laparoscopic cystectomy and ileal conduit formation, and/or LPN. It is unlikely that experienced laparoscopic surgeons would switch to the robotic technique if the robot offers no value. Is it possible to evaluate this in a randomized study? At present, it is impossible because experts cannot go back in time and do an equivalent number of robotic and laparoscopic cases for learning curve equalization. Although now it is clear that certain surgical and clinical outcome parameters are better with RPN, the assertion that LPN is a suitable alternative assumes that surgeons would be able to perform LPN. Pragmatically, however, surgeons cannot easily perform LPN. Learning curve data from experts suggest extreme differences. The quoted learning curve for RPN is approximately 25 cases [4], whereas the learning curve for LPN is estimated to be>200 cases [5]. The fact is that LPN simply is not an option in the modern era, with robotic technology ubiquitous at most major centers. There are no longer enough experienced laparoscopic surgeons to perform LPN in high volume and thus train the next generation of urologists. This does not mean that existing LPN experts should transition to RPN, but it suggests that they may not have proteges who can perform the procedure. It has been increasingly accepted that PN is the standard treatment for T1 renal tumors. Accordingly, the most recent iteration of the American Urological Association’s guidelines references advantages of PN and recommends it as first-line therapy. When compared with radical nephrectomy, PN EURO P E AN URO LOGY 6 7 ( 2 0 1 5 ) 9 0 2 – 9 0 3

Cerebrovascular Disease and Chronic Obstructive Pulmonary Disease Increase Risk of Complications with Robotic Partial Nephrectomy

OBJECTIVE To identify specific comorbidities within the Charlson Comorbidity Index (CCI) that are associated with increased complication rates after robot-assisted partial nephrectomy (RAPN). PATIENTS AND METHODS After institutional review board approval, a consecutive series of 641 patients undergoing RAPN were retrospectively identified. Perioperative complications were defined and classified using the Clavien grading system. Fishers exact test or chi-square test was performed to evaluate the association of individual comorbidities with perioperative complications. Logistic regression was used for multivariable analysis to adjust for other non-CCI comorbidities and tumor-specific and patient-specific characteristics. RESULTS Of the 641 patients undergoing RAPN, complications occurred in 67 patients (10.5%), including 10 (14.9%), 28 (41.8%), 20 (29.9%), 5 (7.5%), and 4 (6.0%) patients with Clavien grade 1, 2, 3a, 3b, and 4 complications, respectively. Cerebrovascular disease [odds ratio 3.01 (95% confidence interval [CI] 1.10, 8.26) p = 0.03] and chronic obstructive pulmonary disease [COPD; 3.12 (1.24, 7.89) p = 0.02] predicted complications in multivariable analysis of clinicopathologic characteristics, including all CCI and non-CCI comorbidities. In additional modeling with only CCI comorbidities, similar results were observed, with cerebrovascular disease [2.93 (1.04, 7.56) p = 0.04] and COPD [2.69 (1.04, 6.28) p = 0.04] as the only two significant variables. No other variables reached statistical significance in either model, including nephrometry score or estimated blood loss (p >  .50 for both). COPD predicted major complications (Clavien grade 3 or 4) in multivariable analysis [3.19 (1.07, 9.48) p = 0.04]. CONCLUSIONS Cerebrovascular disease and COPD predict perioperative RAPN complications after RAPN. Identification of patients with these comorbidities preoperatively may afford improved counseling and risk stratification.

Diagnostic Utility of Selective Upper Tract Urinary Cytology: A Systematic Review and Meta-analysis of the Literature.

The diagnosis of upper tract urothelial carcinoma (UTUC) can be a challenging diagnostic pursuit. To date, there is no large-scale study assessing the statistical utility (eg, sensitivity and specificity) of selective cytology. Herein, we systematically reviewed and meta-analyzed the published literature to evaluate the efficacy of selective cytology for the detection of UTUC in patients with a suspicious clinical profile Selective cytology confers a high specificity but marginal sensitivity for the detection of UTUC. The sensitivity is greater for high-grade UTUC lesions. The statistical assessment of its utility is limited by the heterogeneity and bias of previous studies.

The Probability of Aggressive Versus Indolent Histology Based on Renal Tumor Size: Implications for Surveillance and Treatment

BACKGROUND While the probability of malignant versus benign histology based on renal tumor size has been described, this alone does not sufficiently inform decision-making in the modern era since indolent malignant tumors can be managed with active surveillance. OBJECTIVE To characterize the probability of aggressive versus indolent histology based on radiographic tumor size. DESIGN, SETTING, AND PARTICIPANTS We evaluated patients who underwent radical or partial nephrectomy at Mayo Clinic for a pT1-2, pNx/0, M0 solid renal tumor between 1990 and 2010. Pathology was reviewed by one genitourinary pathologist. High-grade clear-cell renal cell carcinoma (RCC), high-grade papillary RCC, collecting duct RCC, translocation-associated RCC, hereditary leiomyomatosis RCC, unclassified RCC, and malignant non-RCC tumors were all considered aggressive, as well as any tumors demonstrating coagulative necrosis (except low-grade papillary RCC) or sarcomatoid differentiation. The remaining benign and malignant tumors were considered indolent. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Cancer-specific survival (CSS) was estimated using the Kaplan-Meier method. Logistic regression models were used to estimate the probability of malignant and aggressive histology based on tumor size. Sex-stratified analyses were also performed. RESULTS AND LIMITATIONS Of the 2650 patients included, there were 1860 patients with indolent tumors (300 benign; 1560 malignant) and 790 with aggressive tumors. The 10-yr CSS was 96% for indolent malignant tumors and 81% for aggressive malignant tumors. The predicted percentages of any malignant histology as well as aggressive histology increased with tumor size. Specifically, 2cm, 3cm, and 4cm tumors have an estimated 84%, 87%, and 88% likelihood of malignancy, respectively, and an 18%, 24%, and 29% likelihood of aggressive histology, respectively. For any given tumor size, men had a greater chance of aggressive histology than women. Potential limitations of this observational surgical cohort include selection bias. CONCLUSIONS We present tumor size-based estimates of the probability of aggressive histology for renal masses. This information should be useful for initial patient counseling and management. PATIENT SUMMARY Active surveillance is an option for kidney masses, even if they are malignant. Beyond knowing whether the mass is benign or cancer, it is important to know whether or not it is an aggressive tumor. This study presents tumor size-specific and sex-specific estimates of the probability of cancer overall and aggressive cancer among patients with a kidney mass in order to aid with initial decision-making.

Catheterization alters bladder ecology to potentiate Staphylococcus aureus infection of the urinary tract

Significance Staphylococcus aureus is a cause of catheter-associated urinary tract infections (CAUTIs). S. aureus CAUTIs are problematic because they are usually caused by antibiotic-resistant strains, and patients who develop these infections have a high risk of developing serious complications. Catheterization in humans and mice causes damage in the bladder that results in the release of host protein fibrinogen (Fg). This study suggests that S. aureus exploits the presence of Fg via interactions mediated by the Fg-binding protein ClfB to facilitate colonization of the bladder and the catheter to cause a persistent infection in both mice and humans. Insights into S. aureus CAUTI pathogenesis is facilitating the development of more-targeted therapies to better treat these infections. Methicillin-resistant Staphylococcus aureus (MRSA) is an emerging cause of catheter-associated urinary tract infection (CAUTI), which frequently progresses to more serious invasive infections. We adapted a mouse model of CAUTI to investigate how catheterization increases an individual’s susceptibility to MRSA UTI. This analysis revealed that catheterization was required for MRSA to achieve high-level, persistent infection in the bladder. As shown previously, catheter placement induced an inflammatory response resulting in the release of the host protein fibrinogen (Fg), which coated the bladder and implant. Following infection, we showed that MRSA attached to the urothelium and implant in patterns that colocalized with deposited Fg. Furthermore, MRSA exacerbated the host inflammatory response to stimulate the additional release and accumulation of Fg in the urinary tract, which facilitated MRSA colonization. Consistent with this model, analysis of catheters from patients with S. aureus-positive cultures revealed colocalization of Fg, which was deposited on the catheter, with S. aureus. Clumping Factors A and B (ClfA and ClfB) have been shown to contribute to MRSA–Fg interactions in other models of disease. We found that mutants in clfA had significantly greater Fg-binding defects than mutants in clfB in several in vitro assays. Paradoxically, only the ClfB− strain was significantly attenuated in the CAUTI model. Together, these data suggest that catheterization alters the urinary tract environment to promote MRSA CAUTI pathogenesis by inducing the release of Fg, which the pathogen enhances to persist in the urinary tract despite the host’s robust immune response.

Transmesenteric robot-assisted pyeloplasty for ureteropelvic junction obstruction in horseshoe kidney

CAsE The patient is a 28-year old female with an obstructed ureteropelvic junction (UPJ) of the left moiety of a horseshoe kidney. The Da Vinci S robotic platform was used. After transperitoneal access was obtained, a window in the mesentery was identified, and the renal pelvis was exposed. A dismembered, spatulated pyeloplasty was performed with transposition of the UPJ to a more dependent portion of the renal pelvis. A ureteral stent and closed surgical drain were placed.

Metastatic Granulosa Cell Tumor of the Testis: Clinical Presentation and Management

Granulosa cell tumors (GCTs) of the testis are rare sex cord-stromal tumors that are present in both juvenile and adult subtypes. While most adult GCTs are benign, those that present with distant metastases manifest a grave prognosis. Treatments for aggressive GCTs are not well established. Options that have been employed in previous cases include retroperitoneal lymph node dissection (RPLND), radiation, chemotherapy, or a combination thereof. We describe the case of a 57-year-old man who presented with a painless left testicular mass and painful gynecomastia. Serum tumor markers (alpha fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase) and computed tomography of the chest and abdomen were negative. The patient underwent left radical orchiectomy. Immunohistochemical staining was consistent with a testicular GCT. He underwent a left-template laparoscopic RPLND which revealed 2/19 positive lymph nodes. Final pathological stage was IIA. He remains free of disease 32 months after surgery.