Renal Neuroendocrine Neoplasms: A Single-center Experience.

BACKGROUND: Primary neuroendocrine neoplasms (NENs) of the kidney are exceedingly rare malignancies and the available literature is very limited. The natural history and response to treatments is not well characterized. We aimed to describe the presenting features, demographics, tumor characteristics, and treatment outcomes of patients with renal NENs. PATIENTS AND METHODS: We performed a retrospective analysis of all Mayo Clinic patient records with a tissue diagnosis of a primary renal NEN. Baseline patient and surgical pathologic features and treatment modalities were collected. Time to recurrence after resection and overall survival (OS) were estimated using with survival analysis. Surveillance, Epidemiology, and End Results data were used to estimate the population-wide incidence and OS. RESULTS: A total of 17 patients were included in the present study, with a median follow-up of 62.8 months. Distant metastasis was present in 29% at diagnosis, with 76% experiencing distant metastasis at any point; 24% had a horseshoe kidney. Of the 17 patients, 14 had undergone surgical resection with no evidence of disease postoperatively. Ten of these patients had documented recurrence. The median time to recurrence was 18 months (95% confidence interval, 9-46 months). Only 1 of the 10 patients showed a radiographic response to systemic therapy. Of 9 patients, 4 had stable disease with somatostatin analogs. The median OS was 143 months (95% confidence interval, 50-143 months). CONCLUSIONS: Renal NENs are rare malignancies affecting mostly middle-age patients, with distant metastasis being common. Approximately one half of patients experience stable disease with somatostatin analogs. The OS usually exceeds 5 years.

Artificial urinary sphincter revision with Quick Connects® versus suture-tie connectors: does technique make a difference?

OBJECTIVE: To evaluate characteristics of artificial urinary sphincter (AUS) mechanical failures and compare outcomes based on the use of either suture-tied connections or Quick-Connects® (QC) for single-component revisions. MATERIAL AND METHODS: A total of 46 patients underwent single-component AUS revisions following primary AUS placement from January 1983 to January 2011 at our institute. Prior to 1996 all revision cases were performed with suture-tie connections and after that time we used QC for revisions. Device success was evaluated for a potential association with revision surgery including the type of connector used. RESULTS: Forty-six patients underwent single-component revision surgery for primary device malfunction. In these cases, the tubing connections were performed using suture-tie connectors in 34 (74%), and QC in 12 (26%) cases. The median age was 68.8 years for suture-tie vs 70.6 years for QC (p=0.52). The median follow-up period after revision surgery was 24 months (IQR 7.2, 55.2). There was no statistically significant difference in 5-year device survival rates between suture-tie and QC (36% vs. 61%; p=0.85) techniques. There were no cases of device infection or repeat mechanical failure at the connector among cases of revision performed using QC, as compared to five device infections and four repeat mechanical failures among the suture-tie cohort. CONCLUSION: The use of QC for single-component AUS revision for mechanical failures appears to be safe, efficient and reliable. There is not enough evidence supporting the presence of an association between connector type with the risk of overall device failure.

The Effect of Anticoagulation on Bleeding-related Complications Following Ureteroscopy.

OBJECTIVE: To analyze bleeding-related complications among patients on long-term anticoagulation (AC) undergoing ureteroscopy (URS). Current American Urological Association/International Consultation on Urological Diseases guidelines state that it is safe to continue AC in routine URS; however, these recommendations are based on small case series. PATIENTS AND METHODS: There were 4799 identified URS procedures performed at our institution between June 2009 and February 2016. Records were then retrospectively reviewed to confirm AC use and identify periprocedural complications. Anticoagulant agents evaluated included warfarin, enoxaparin, and non-vitamin K antagonists (ie, rivaroxaban, dabigatran, apibaxan). Patients were excluded if they were taking a concurrent antiplatelet (AP) agent or if additional non-URS procedures were performed. RESULTS: Of the 4799 URS procedures, 272 (5.6%) were done on patients taking chronic AC. Of these, 193 (71%) held AC, 53 (19%) were bridged with enoxaparin, and 26 (10%) continued AC. The median age was 70.2 years and the majority of patients (64.2%) underwent a stone procedure with a stone-free rate of 73%. The overall bleeding-related complication rate was 8.1% whereas the significant bleeding-related event rate was 5.9%. Patients continuing AC had the highest significant bleeding-related event rate at 15.4% compared to 9% and 3% for those bridged with enoxaparin and those who held, respectively (P = .01). CONCLUSION: Continuation or bridging of AC may increase the risk of perioperative bleeding. The risks and benefits of proceeding with URS on AC must be weighed carefully. Pending external validation, this information may be used for patient counseling and risk stratification.

The Effect of Antiplatelet Agents on Bleeding-Related Complications After Ureteroscopy.

INTRODUCTION: The American Urological Association (AUA) guidelines state that continuing anticoagulation and antiplatelet agents in routine ureteroscopy (URS) is safe and without increased risk of complications. However, these recommendations are based on small case series; thus, we sought to analyze bleeding-related complications among patients on antiplatelet therapy (APT). MATERIALS AND METHODS: Overall, 4799 URS procedures performed at our institution between June 2009 and February 2016 were identified. Records were then retrospectively reviewed to confirm APT use and to identify periprocedural complications. Antiplatelet agents evaluated included aspirin (low dose and full dose) and P2Y12 receptor antagonists (clopidogrel, prasugugrel, ticagrelor). Patients were excluded if they were taking a concurrent anticoagulant agent or if additional non-URS procedures were performed. RESULTS: Of 4799 URS procedures, 314 (6.5%) were performed on patients taking APT, of which 234 (74.5%) held APT, 63 (20.1%) continued APT, and 17 (5.4%) continued dual APT. The mean age was 70.1 years, and the majority of patients (69.6%) underwent a stone procedure with a stone-free rate of 80.2%. The overall bleeding-related complication rate was 1.9%, whereas the significant bleeding-related event rate was 1.6% and this did not differ among the groups (p = 0.3). The power to detect a 3% difference in bleeding between the groups was 0.95. CONCLUSIONS: Continuing APT in patients on chronic therapy does not appear to pose an increased risk of bleeding-related complications. Our findings support the current AUA guidelines as they relate to APT.

Surgeon fatigue: impact of case order on perioperative parameters and patient outcomes.

PURPOSE: We tested the hypothesis that surgeon fatigue results in worse outcomes for laparoscopic and robot-assisted laparoscopic prostatectomy, and percutaneous nephrolithotomy by comparing outcomes of sequentially scheduled procedures. MATERIALS AND METHODS: We identified days when 2 procedures of the same type were performed by the same surgeon, including 72 laparoscopic and 340 robot-assisted laparoscopic prostatectomies, and 110 percutaneous nephrolithotomies. Clinical data and outcomes were compared. RESULTS: For percutaneous nephrolithotomy multiple access (16% vs 9%, p = 0.2), transfusion (3.6% vs 5.4%, p = 0.5), complication (20% vs 18%, p = 0.5), residual fragment (53% vs 45%, p = 0.3), second look (38% vs 35% p = 0.4) and stone-free (86% vs 89% p = 0.3) rates did not differ for the first and second procedures. For laparoscopic prostatectomy nerve sparing (100% vs 97.1%, p = 0.5), operative complications (0% vs 0%, p = 0.7), drain requirement (36% vs 42%, p = 0.6) and lymphadenectomy (13.5% vs 25.7%, p = 0.16) rates were comparable. Positive margins (19.4% vs 36.1% p = 0.08), continence (66.7% vs 66.7%, p = 0.9), potency (58.3% vs 52.8%, p = 0.76) and prostate specific antigen recurrence (10.8% vs 20%, p = 0.45) did not significantly differ for the first and second procedures. For robot-assisted laparoscopic prostatectomy operative complications (3% vs 3.5%, p = 0.8), drain requirement (7.7% vs 9.8%, p = 0.5), positive margins (41.7% vs 39.3%, p = 0.37), continence (78.6% vs 84.4%, p = 0.12), potency (51% vs 50%, p = 0.15) and prostate specific antigen recurrence (9.5% vs 11.6%, p = 0.2) did not significantly differ. Nerve sparing was more common in the second case cohort (86.9% vs 75.7%, p = 0.03). CONCLUSIONS: Despite concern that surgeon fatigue may impact outcomes, our data suggests that performing several complex urological procedures consecutively is not associated with worse outcomes.

Isolation and characterization of CvIV4: a pain inducing α-scorpion toxin.

BACKGROUND: Among scorpion species, the Buthidae produce the most deadly and painful venoms. However, little is known regarding the venom components that cause pain and their mechanism of action. Using a paw-licking assay (Mus musculus), this study compared the pain-inducing capabilities of venoms from two species of New World scorpion (Centruroides vittatus, C. exilicauda) belonging to the neurotoxin-producing family Buthidae with one species of non-neurotoxin producing scorpion (Vaejovis spinigerus) in the family Vaejovidae. A pain-inducing α-toxin (CvIV4) was isolated from the venom of C. vittatus and tested on five Na(+) channel isoforms. PRINCIPAL FINDINGS: C. vittatus and C. exilicauda venoms produced significantly more paw licking in Mus than V. spinigerus venom. CvIV4 produced paw licking in Mus equivalent to the effects of whole venom. CvIV4 slowed the fast inactivation of Na(v)1.7, a Na(+) channel expressed in peripheral pain-pathway neurons (nociceptors), but did not affect the Na(v)1.8-based sodium currents of these neurons. CvIV4 also slowed the fast inactivation of Na(v)1.2, Na(v)1.3 and Na(v)1.4. The effects of CvIV4 are similar to Old World α-toxins that target Na(v)1.7 (AahII, BmK MI, LqhIII, OD1), however the primary structure of CvIV4 is not similar to these toxins. Mutant Na(v)1.7 channels (D1586A and E1589Q, DIV S3-S4 linker) reduced but did not abolish the effects of CvIV4. CONCLUSIONS: This study: 1) agrees with anecdotal evidence suggesting that buthid venom is significantly more painful than non-neurotoxic venom; 2) demonstrates that New World buthids inflict painful stings via toxins that modulate Na(+) channels expressed in nociceptors; 3) reveals that Old and New World buthids employ similar mechanisms to produce pain. Old and New World α-toxins that target Na(v)1.7 have diverged in sequence, but the activity of these toxins is similar. Pain-inducing toxins may have evolved in a common ancestor. Alternatively, these toxins may be the product of convergent evolution.