Adhesive Bowel Obstruction Following Urologic Surgery: Improved Outcomes with Early Intervention.

Objective: To describe the long-term incidence of adhesive bowel obstruction following major urologic surgery, and the effect of early surgery on perioperative outcomes. Methods: The Healthcare Cost and Utilization Project State Inpatient Databases for California and Florida (2006-2011) were used to identify major urologic oncologic surgery patients. Subsequent adhesive bowel obstruction admissions were identified and Kaplan-Meier time-to-event analysis was performed. Early surgery for bowel obstruction was defined as occurring on-or-before hospital-day four. The effects of early surgery on postoperative minor/moderate complications (wound infection, urinary tract infection, deep vein thrombosis, and pneumonia), major complications (myocardial infarction, pulmonary embolism, and sepsis), death, and postoperative length-of-stay were assessed. Results: Major urologic surgery was performed on 104,400 patients, with subsequent 5-year cumulative incidence of adhesive bowel obstruction admission of 12.4% following radical cystectomy, 3.3% following kidney surgery, and 0.9% following prostatectomy. During adhesive bowel obstruction admission, 71.6% of patients were managed conservatively and 28.4% surgically. Early surgery was performed in 65.4%, with decreased rates of minor/moderate complications (18 vs. 30%, p = 0.001), major complications (10 vs. 19%, p = 0.002), and median postoperative length of stay (8 vs. 11 days, p < 0.001) compared with delayed surgery. On multivariate analysis early surgery decreased the odds of minor/ moderate complications by 43% (p = 0.01), major complications by 45% (p = 0.03), and postoperative length of stay by 3.1 days (p = 0.01). Conclusion: Adhesive bowel obstruction is a significant long-term sequela of urologic surgery, for which early surgical management may be associated with improved perioperative outcomes.

Complications of Recognized and Unrecognized Iatrogenic Ureteral Injury at Time of Hysterectomy: A Population Based Analysis.

PURPOSE: Ureteral injury represents an uncommon but potentially morbid surgical complication. We sought to characterize the complications of iatrogenic ureteral injury and assess the effect of recognized vs delayed recognition on patient outcomes. MATERIALS AND METHODS: Patients who underwent hysterectomy were identified in the Healthcare Cost and Utilization Project California State Inpatient Database for 2007 to 2011. Ureteral injuries were identified and categorized as recognized-diagnosed/repaired on the day of hysterectomy and unrecognized-diagnosed/repaired postoperatively. We assessed the outcomes of 90-day hospital readmission as well as 1-year outcomes of nephrostomy tube placement, urinary fistula, acute renal failure, sepsis and overall mortality. The independent effects of recognized and unrecognized ureteral injuries were determined on multivariate analysis. RESULTS: Ureteral injury occurred in 1,753 of 223,872 patients (0.78%) treated with hysterectomy and it was unrecognized in 1,094 (62.4%). The 90-day readmission rate increased from a baseline of 5.7% to 13.4% and 67.3% after recognized and unrecognized injury, respectively. Nephrostomy tubes were required in 2.3% of recognized and 23.4% of unrecognized ureteral injury cases. Recognized and unrecognized ureteral injuries independently increased the risk of sepsis (aOR 2.0, 95% CI 1.2-3.5 and 11.9, 95% CI 9.9-14.3) and urinary fistula (aOR 5.9, 95% CI 2.2-16 and 124, 95% CI 95.7-160, respectively). During followup unrecognized ureteral injury increased the odds of acute renal insufficiency (aOR 23.8, 95% CI 20.1-28.2) and death (1.4, 95% CI 1.03-1.9, p = 0032). CONCLUSIONS: Iatrogenic ureteral injury increases the risk of hospital readmission and significant, potentially life threatening complications. Unrecognized ureteral injury markedly increases these risks, warranting a high level of suspicion for ureteral injury and a low threshold for diagnostic investigation.

A Case of Renal Metastasis of Uterine Leiomyosarcoma.

A 49-year-old woman with a distant history of uterine leiomyosarcoma underwent robotic-assisted laparoscopic partial nephrectomy for a 3.5 cm right renal mass, which was presumed to be a primary renal cell carcinoma. Surgical margins were negative, and the histologic analysis confirmed leiomyosarcoma. Uterine leiomyosarcoma is traditionally a locally aggressive disease with only rare reports of renal involvement. We report a case of a metastatic leiomyosarcoma to the kidney four years following initial treatment for uterine leiomyosarcoma.

Functional Comparison of Renal Tumor Enucleation Versus Standard Partial Nephrectomy.

BACKGROUND: Tumor enucleation (TE) optimizes parenchymal preservation and could yield better function than standard partial nephrectomy (SPN), although data on this are conflicting. OBJECTIVE: To compare functional outcomes for TE and SPN strategies. DESIGN, SETTING, AND PARTICIPANTS: Patients managed with partial nephrectomy (PN) with necessary data for analysis of preservation of ipsilateral parenchymal mass (IPM) and global glomerular filtration rate (GFR) from two centers were included. All studies were required <2 mo before and 3-12 mo after surgery. Patients with a solitary kidney or multifocal tumors were excluded. INTERVENTION: Partial nephrectomy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Vascularized IPM was estimated from contrast-enhanced CT scans preoperatively and postoperatively. Serum creatinine-based estimates of global GFR were also obtained in the same timeframes. Univariable and multivariable linear regression evaluated factors associated with new-baseline global GFR. RESULTS/LIMITATIONS: Analysis included 71 TE and 373 SPN cases. The median preoperative global GFR was comparable for TE and SPN (75 vs 78ml/min/1.73m2; p=0.6). The median tumor size was 3.0cm for TE and 3.3cm for SPN (p=0.03). The median RENAL score was 7 in both cohorts. For TE, warm ischemia and zero ischemia were used in 51% and 49% of cases, respectively. For SPN, warm ischemia and cold ischemia were used in 72% and 28% of patients, respectively. Capsular closure was performed in 46% of TE and 100% of SPN cases (p<0.001). Positive margins were found in 8.5% of TE and 4.8% of SPN patients (p=0.2). The median vascularized IPM preserved was 95% (interquartile range [IQR] 91-100%) for TE and 84% (IQR 76-92%) for SPN (p<0.001). The median global GFR preserved was 101%(IQR 93-111%) and 89% (IQR 81-96%) for TE and SPN, respectively (p<0.001). On multivariable analysis, resection strategy, preoperative GFR, and vascularized IPM preserved were all significantly associated (p<0.001) with new-baseline global GFR. Limitations include the retrospective design and the lack of resection outcome data. CONCLUSIONS: Our analysis suggests that TE has potential for maximum IPM preservation compared to SPN and may provide optimized functional recovery. Further investigation will be required to evaluate the clinical significance of these findings. PATIENT SUMMARY: Tumor enucleation for kidney cancer involves dissection along the tumor capsule and optimally preserves normal kidney tissue, which may lead to better functional recovery. The importance of this approach in various clinical settings will require further investigation.

Postoperative Urinary Retention is an Independent Predictor of Short-Term and Long-Term Future Bladder Outlet Procedure in Men.

PURPOSE: Postoperative urinary retention is a common complication across surgical specialties. To our knowledge no literature to date has examined postoperative urinary retention as a predictor of long-term receipt of surgery for bladder outlet obstruction. MATERIALS AND METHODS: We retrospectively reviewed the records of inpatients who underwent nonurological surgery in California between 2008 and 2010. Postoperative urinary retention during the index admission was identified, as was receipt of a bladder outlet procedure (transurethral prostate resection, prostate photoselective vaporization or suprapubic prostatectomy) at a subsequent encounter. Patients were matched using propensity scoring of demographics, comorbidities and surgery type. Adjusted Kaplan-Meier analysis was performed to determine the cumulative incidence of subsequent bladder outlet procedures by patient group, including group 1-age 60 years or greater and postoperative urinary retention, group 2-age 60 years or greater and no postoperative urinary retention, group 3-age less than 60 years and postoperative urinary retention, and group 4-age less than 60 years and no postoperative urinary retention. RESULTS: Of 769,141 eligible male patients postoperative urinary retention developed in 8,051 (1.1%). Following hospital discharge 1,855 patients (0.24%) underwent a bladder outlet procedure. Those treated with a bladder outlet procedure were significantly more likely to have experienced postoperative urinary retention during the index admission (6.3% vs 1.0%, p <0.001). On matched analysis the bladder outlet procedure rate at 3 years was 7.1%, 2.2%, 0.8% and 0.0% in groups 1, 2, 3 and 4, respectively. CONCLUSIONS: In men 60 years old or older postoperative urinary retention identified those with an increased incidence of bladder outlet procedures within 3 years. Men younger than 60 years had a low rate of subsequent bladder outlet procedures regardless of a postoperative urinary retention diagnosis.

Rates and Risk Factors for Opioid Dependence and Overdose after Urological Surgery.

PURPOSE: Effective pain management is a critical component of the perioperative process with opioids representing a mainstay of therapy. The opioid epidemic is a growing concern in the United States. The goal of this study was to quantify the risk of opioid dependence or overdose among patients undergoing urological surgery and to identify risk factors of opioid dependence or overdose. MATERIALS AND METHODS: We retrospectively reviewed data on urological surgery from 2007 to 2011. Data sources included the HCUP (Healthcare Cost and Utilization Project) inpatient, ambulatory surgery and emergency department data sets. Outcomes of postoperative opioid dependence and overdose were identified by previously validated ICD-9 codes. Multivariable logistic regression adjusted for surgical procedure was performed to identify predictors of opioid dependence or overdose following urological surgery. RESULTS: Overall 675,527 patients underwent urological surgery, of whom 0.09% were diagnosed with opioid dependence or overdose. Patients in whom opioid dependence or overdose developed were younger (median age 51 vs 62 years), carried nonprivate insurance (69.6% vs 66%), underwent an inpatient procedure (81.0% vs 42.4%) and had a longer length of stay (median 3 vs 0 days) and a history of depression (14.4% vs 3.4%) or chronic obstructive pulmonary disease (20.3% vs 8.9%, all p <0.001). On adjusted multivariable analysis these factors remained independent risk factors for opioid dependence or overdose. CONCLUSIONS: Postoperative opioid dependence or overdose affects 1 of 1,111 urological surgery patients. Risk factors for opioid dependence or overdose included younger age, inpatient surgery and increasing hospitalization duration, baseline depression, tobacco use and chronic obstructive pulmonary disease as well as insurance provider, including Medicaid, Medicare (age less than 65 years) and noninsured status.

Cost Analysis of Metallic Stents for Chronic Ureteral Obstruction: A Multicenter Study.

INTRODUCTION: Metallic and polymer ureteral stents are used to manage chronic ureteral obstruction. In general, metallic stents are more costly than polymer stents but they are changed less frequently. We examined the overall costs of using these stent types at 2 institutions. METHODS: We identified all patients in whom a metallic stent was placed at 2 academic institutions between July 2007 and July 2013. We calculated the average time to stent exchange or failure and the overall cost of metallic and polymer stent use. Costs included those associated with materials, operating room services, anesthesia and other expenses. RESULTS: We identified 86 patients in whom a total of 230 metallic stents were placed. Time to stent failure or exchange of a metallic stent was 7.4 months. The per unit cost of a polymer stent and a metallic stent was $121 and $887, respectively. The average annual cost of unilateral and bilateral metallic stents was $7,859.43 and $9,296.37, respectively. For a unilateral polymer stent that was changed every 3 months the yearly cost was $16,342. For bilateral polymer stents that were changed every 3 months the cost was $16,826 per year. If unilateral and bilateral polymer stents were changed every 6 months, the costs were $8,171 and $8,413, respectively. CONCLUSIONS: Our findings suggest that because metallic stents are changed less frequently than polymer stents, the annual expense associated with treating patients with chronic ureteral obstruction can be decreased by using metallic stents.

Functional Implications of Renal Tumor Enucleation Relative to Standard Partial Nephrectomy.

OBJECTIVE: To compare the surgical precision for optimizing nephron-mass preservation of tumor enucleation (TE) vs standard partial nephrectomy (SPN), with primary focus on functional outcomes. TE is presumed to optimize preservation of parenchymal mass and function but this has not yet been rigorously studied and quantified. MATERIALS AND METHODS: Robotic partial nephrectomy patients who had appropriate pre- and postoperative studies for analysis of parenchymal mass preservation specific to the operated kidney were included. Computed tomography or magnetic resonance imaging and estimated glomerular filtration rate were required to be <2 months prior and 4-12 months after surgery. Parenchymal mass preservation and surgical precision were estimated for each technique, with precision defined as actual postoperative parenchymal volume or predicted postoperative parenchymal volume, presuming loss of a 5 mm rim of parenchyma associated with tumor excision and reconstruction. RESULTS: Analysis included 57 TE and 53 SPN. Median age, body mass index, and tumor size were comparable. Percent parenchymal mass preserved in the operated kidney with TE was 96% (interquartile range [IQR] = 90-100) vs 89% (IQR = 83-96) for SPN (P = .003). Precision of excision or reconstruction was 101% (IQR = 96-105) for TE vs 94% (IQR = 88-100) for SPN (P < .001). On multivariable analysis, only TE correlated with improved surgical precision (coefficient = 6.7, 95% confidence interval = 1.6-11.8, P = .01). Although preservation of global renal function also favored TE, the differences were marginal (96% vs 93%), and statistical significance was not observed (P = .2). CONCLUSION: Our analysis, which specifically focuses on the functional implications of TE, demonstrates that TE maximally spares normal parenchyma compared to SPN. Thus far, functional differences remain marginal and not statistically significant. Clinical significance of these findings in various clinical settings will require further investigation.

HSV-1 infection of human corneal epithelial cells: receptor-mediated entry and trends of re-infection.

PURPOSE: The human cornea is a primary target for herpes simplex virus-1 (HSV-1) infection. The goals of the study were to determine the cellular modalities of HSV-1 entry into human corneal epithelial (HCE) cells. Specific features of the study included identifying major entry receptors, assessing pH dependency, and determining trends of re-infection. METHODS: A recombinant HSV-1 virus expressing beta-galactosidase was used to ascertain HSV-1 entry into HCE cells. Viral replication within cells was confirmed using a time point plaque assay. Lysosomotropic agents were used to test for pH dependency of entry. Flow cytometry and immunocytochemistry were used to determine expression of three cellular receptors--nectin-1, herpesvirus entry mediator (HVEM), and paired immunoglobulin-like 2 receptor alpha (PILR-a). The necessity of these receptors for viral entry was tested using antibody-blocking. Finally, trends of re-infection were investigated using viral entry assay and flow cytometry post-primary infection. RESULTS: Cultured HCE cells showed high susceptibility to HSV-1 entry and replication. Entry was demonstrated to be pH dependent as blocking vesicular acidification decreased entry. Entry receptors expressed on the cell membrane include nectin-1, HVEM, and PILR-α. Receptor-specific antibodies blocked entry receptors, reduced viral entry and indicated nectin-1 as the primary receptor used for entry. Cells re-infected with HSV-1 showed a decrease in entry, which was correlated to decreased levels of nectin-1 as demonstrated by flow cytometry. CONCLUSIONS: HSV-1 is capable of developing an infection in HCE cells using a pH dependent entry process that involves primarily nectin-1 but also the HVEM and PILR-α receptors. Re-infected cells show decreased levels of entry, correlated with a decreased level of nectin-1 receptor expression.

Resistance to forgetting associated with hippocampus-mediated reactivation during new learning.

One of the reasons why we forget past experiences is because we acquire new memories in the interim. Although the hippocampus is thought to be important for acquiring and retaining memories, there is little evidence linking neural operations during new learning to the forgetting (or remembering) of earlier events. We found that, during the encoding of new memories, responses in the human hippocampus are predictive of the retention of memories for previously experienced, overlapping events. This brain-behavior relationship is evident in neural responses to individual events and in differences across individuals. We found that the hippocampus accomplishes this function by reactivating older memories as new memories are formed; in this case, reactivating neural responses that represented monetary rewards associated with older memories. These data reveal a fundamental mechanism by which the hippocampus tempers the forgetting of older memories as newer memories are acquired.