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Dive into the research topics where Zachary L. Smith is active.

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Featured researches published by Zachary L. Smith.


Journal of Endourology | 2014

A Novel Use of Near-Infrared Fluorescence Imaging During Robotic Surgery Without Contrast Agents

Mark Hockenberry; Zachary L. Smith; Phillip Mucksavage

We describe a novel use of near-infrared fluorescence (NIRF) imaging without contrast agents, like indocyanine green, to identify otherwise obscured intraluminal areas of interest during robot-assisted laparoscopic (RAL) surgery marked by the white light (WL) of endoscopic instruments. By filtering light wavelengths below near-infrared, NIRF imaging causes the WL of the endoscopes to illuminate green while allowing simultaneous vision of the surrounding tissues. With this visualization, intraoperative ureteroscopy was used to identify the extent of a ureteral stricture in a patient undergoing RAL partial ureterectomy. Cystoscopy was used to identify bladder diverticula and tumor locations in three patients undergoing RAL partial cystectomy with or without diverticulectomy and the ureteral orifice in another patient undergoing RAL nephroureterectomy. This technique enabled more precise identification of important areas and successful completion of RAL surgery in these five patients, which serves as proof of concept for broader applications in RAL surgery.


Journal of Clinical Gastroenterology | 2013

Relationship between mesenteric abnormalities on computed tomography and malignancy: clinical findings and outcomes of 359 patients.

Zachary L. Smith; Humberto Sifuentes; David Ecanow; Eli D. Ehrenpreis

Background: Mesenteric abnormalities are detected on abdominal computed tomography (CT) performed for various indications. Goals: Determine the risk of malignancy on follow-up of patients with these abnormalities without a preexisting malignancy. Study: Data were collected on all patients at NorthShore University HealthSystem with abdominal CT scan reports of mesenteric abnormalities labeled as “panniculitis” from January 2005 to April 2010. Results: Three hundred fifty-nine patients were identified, 81 (22.6%) had a known malignancy at the time of the index abdominal CT scan. Nineteen (6.8%) of the 278 had a new diagnosis of malignancy on evaluation of the findings of the index CT scan. Among the 240 (86.33%) that did not have a notation of the abnormality in their medical record, 11 (4.58%) developed a malignancy during the study period. Sixty-eight of the 248 (24.46%) without a known malignancy had diseases associated with mesenteric abnormalities. The presence of these were associated with a reduction in the likelihood that the abnormalities are associated with new or delayed diagnosis of a malignancy (odds ratio, 0.197; 95% confidence interval, 0.0045-0.8501; P=0.013). Progression of underlying malignancy was unlikely in those where the mesenteric abnormalities did not worsen in appearance on follow-up CT scans (odds ratio, 0.03268; 95% confidence interval, 0.0028-0.3761; P=0.0061). Conclusions: In the presence of an underlying disease associated with these findings, the subsequent finding of a malignancy is less likely. In addition, neglect of these findings may result in delayed diagnosis of cancer.


Urologic Oncology-seminars and Original Investigations | 2017

Temporal trends in perioperative morbidity for radical cystectomy using the National Surgical Quality Improvement Program database

Scott Johnson; Zachary L. Smith; Shay Golan; Joseph F. Rodriguez; Norm D. Smith; Gary D. Steinberg

INTRODUCTION Radical cystectomy (RC) is the standard of care for invasive nonmetastatic bladder cancer. Unfortunately, it is a complex procedure and more than half of patients experience a complication. A number of efforts to reduce perioperative morbidity have been made, including alterations in pain management, antibiotics, diet advancement, and anticoagulation. Many of these changes in management have been studied with favorable results; however, it is not clear whether complication rates following RC have improved in recent years. With this in mind we sought to evaluate current temporal trends in postoperative complication rates following RC using a large national dataset. MATERIALS AND METHODS Using the National Surgical Quality Improvement Program participant use files from 2010 to 2015, we identified patients undergoing RC using current procedural terminology codes. Demographic information as well as 30-day complications, length of stay (LOS), readmission and death were compared according to year of operation using univariable and multivariable analysis. RESULTS Over the 6 year period analyzed, 6,510 patients were identified for analysis. Age and comorbidity were similar across the study period. A robotic approach was used in 5.8% of the entire cohort which did not differ among years. A total of 15.9% of patients underwent a continent urinary diversion, with a trend toward decreased use in recent years, 31.5% of patients experienced a complication and this did not differ significantly among years, and 40.7% of patients required a blood transfusion overall with a trend toward decreased use. LOS decreased over time from 10.6 days in 2010 to 9.2 days in 2015 (P<0.01) whereas readmissions increased slightly over the time period to 21.4% in 2015 (P<0.01). CONCLUSIONS RC remains a procedure associated with high morbidity. In the recent era of enhanced recovery protocols, complication rates have not changed significantly, however, there has been a consistent decline in LOS and use of blood transfusion.


Current Urology Reports | 2016

Current Status of Minimally Invasive Surgery for Renal Cell Carcinoma

Zachary L. Smith

Over the last three decades, the incidence of renal cell carcinoma (RCC) has continuously risen, generally attributed to the increased use of cross-sectional imaging across all medical disciplines. Fortunately, despite this rising incidence, the estimated 5-year relative survival rate has improved. This survival improvement likely parallels the stage migration of the last two decades toward an increased incidence of small renal masses (SRMs). However, this survival improvement may be secondary to improved surgical techniques and medical therapies for these malignancies. The increased incidence of SRMs has led to an expected evolution in the treatment of RCC. Minimally invasive surgical applications for the treatment of RCC have gained widespread popularity, and now these approaches to renal malignancies have surpassed open techniques in frequency of utilization. Laparoscopic and robotic-assisted techniques have now been applied to both radical and partial nephrectomy procedures of varying complexity. Additionally, percutaneous ablative procedures have been applied to the treatment of some SRMs, increasing the urologist’s armamentarium further. Below, we provide a review of these minimally invasive surgical (MIS) procedures for the treatment of RCC.


Urologic Oncology-seminars and Original Investigations | 2017

National Surgical Quality Improvement Program surgical risk calculator poorly predicts complications in patients undergoing radical cystectomy with urinary diversion

Shay Golan; Melanie Adamsky; Scott Johnson; Nimrod S. Barashi; Zachary L. Smith; Maria Veronica Rodriguez; Chuanhong Liao; Norm D. Smith; Gary D. Steinberg; Arieh L. Shalhav

PURPOSE To evaluate the accuracy of the American College of Surgeons National Surgical Quality Improvement Programs (ACS-NSQIP) surgical risk calculator in patients undergoing radical cystectomy (RC) with urinary diversion. MATERIALS AND METHODS Preoperative characteristics of patients who underwent RC with ileal conduit or orthotropic neobladder (ONB) between 2007 and 2016 were entered into the proprietary online ACS-NSQIP calculator to generate 30-day predicted risk profiles. Predicted and observed outcomes were compared by measuring Brier score (BS) and area under the receiver operating characteristic curve (AUC). RESULTS Of 954 patients undergoing RC, 609 (64%) received ileal conduit and 345 (36%) received ONB. The calculator underestimated most risks by 10%-81%. The BSs exceeded the acceptable threshold of 0.01 and AUC were less than 0.8 for all outcomes in the overall cohort. The mean (standard deviation) predicted vs. observed length of stay was 9 (1.5) vs. 10.6 (7.4) days (Pearsons r = 0.09). Among patients who received ONB, adequate BS (<0.01) was observed for pneumonia, cardiac complications, and death. The receiver operating characteristic curve analysis revealed moderate accuracy of calculator for cardiac complications (AUC = 0.69) and discharge to rehab center (AUC = 0.75) among patients who underwent RC with ONB. CONCLUSIONS The universal ACS-NSQIP calculator poorly predicts most postoperative complications among patients undergoing RC with urinary diversion. A procedure-specific risk calculator is required to better counsel patients in the preoperative setting and generate realistic quality measures.


The Journal of Urology | 2017

Fistulous Complications following Radical Cystectomy for Bladder Cancer: Analysis of a Large Modern Cohort

Zachary L. Smith; Scott Johnson; Shay Golan; J. Riley McGinnis; Gary D. Steinberg; Norm D. Smith

Purpose Fistula formation is a rare and poorly described complication following radical cystectomy with urinary diversion. We sought to identify patients who experienced any type of fistulous complication and we analyzed risk factors for formation as well as management outcomes. Materials and Methods We retrospectively reviewed the records of patients who underwent radical cystectomy for bladder cancer at our institution. Patients who experienced any fistula were identified. Risk factors, management strategies and outcomes were analyzed. Patients underwent initial conservative treatment and those in whom this treatment failed underwent surgical repair. Univariable and multivariable analyses were performed to identify predictors of fistula formation as well as the need for surgical repair. Results Of the 1,041 patients 31 (3.0%) experienced fistula formation. Median time to fistula presentation was 31 days. Enterodiversion was the most common fistula type, noted in 54.8% of patients, followed by enterocutaneous and diversion cutaneous treatment in 29.0% and 12.9%, respectively. On multivariable analyses a history of radiation therapy (OR 3.1, p = 0.03) and an orthotopic neobladder (OR 3.1, p = 0.04) were predictors of fistula formation. Conservative management was successful in 41.9% of cases. There were no predictors of failed conservative management. Of patients who required surgical repair success was achieved in 94.4% at a single operation. Conclusions Fistulas are rare after radical cystectomy and they are most common between the urinary diversion and the small bowel. A history of radiation therapy and a orthotopic neobladder are risk factors for formation. When required, surgical repair is generally successful at a single operation.


Urology | 2017

Old Tools, Old Problems, New Solution: The Use of a Modified Cecil-Culp Concept in the Trauma Setting

Dana A. Weiss; Zachary L. Smith; Jesse A. Taylor; Douglas A. Canning

A 12-year-old boy sustained a close-range shotgun wound with buckshot to the penis and lower abdomen. The proximal two-thirds of the corpora cavernosa was obliterated and the distal third was thrombosed. All dorsal penile skin was lost. The urethra remained intact. The patient underwent multiple debridements, allowing the wound to declare its borders. Employing the tissue transfer concept used by Cecil and Culp in hypospadias repairs, the penis was marsupialized onto the suprapubic area where it remained for 8 months. After 8 months, the patient underwent a graft delaying procedure followed by a graft harvest 2 months later and penoplasty tubularization.


Current Urology Reports | 2017

African-American Prostate Cancer Disparities

Zachary L. Smith; Adam B. Murphy

Purpose of ReviewThe purpose of this review is to examine prostate cancer racial disparities specific to the African-American population.Recent FindingsAfrican-American men are more likely to be diagnosed with prostate cancer, present at an earlier age; are more likely to have locally advanced or metastatic disease at diagnosis; and have suboptimal outcomes to standard treatments.SummaryProstate cancer treatment requires a nuanced approach, particularly when applying screening, counseling, and management of African-American men. Oncological as well as functional outcomes may differ and are potentially due to a combination of genetic, molecular, behavioral, and socioeconomic factors.


Urology | 2018

Clinical and Radiographic Predictors of Great Vessel Resection or Reconstruction During Retroperitoneal Lymph Node Dissection for Testicular Cancer

Scott Johnson; Zachary L. Smith; Charles U. Nottingham; Zeyad Schwen; Stephen H. Thomas; Elliot K. Fishman; Nam Ju Lee; Philip M. Pierorazio

OBJECTIVE To evaluate whether specific clinical or radiographic factors predict inferior vena cava (IVC) or abdominal aortic (AA) resection or reconstruction (RoR) at the time of postchemotherapy retroperitoneal lymph node dissection (RPLND) for germ cell tumors of the testicle. MATERIALS AND METHODS Two hundred seventy-seven patients undergoing postchemotherapy RPLND at two institutions between 2005 and 2015 were identified. Preoperative imaging was reviewed with radiologists blinded to operative details. Univariable and multivariable logistic regressions were performed, and a model was created to predict the need for great vessel RoR using radiographic and clinical factors. RESULTS Of 97 patients with preoperative imaging and clinical data available, 16 (17%) underwent RoR at RPLND. On univariable analysis dominant mass size, degree of circumferential vessel involvement, and vessel deformity were associated with RoR (all P <.05). No patients with clinical stage IIA or IIB disease at diagnosis required RoR. In the multivariable model, mass involvement of the IVC >135° (odds ratio 65.5, 7.8-548, P <.01) and involvement of the AA >330° (odds ratio 29.0, 3.44-245, P <.01) were predictive for RoR. These thresholds yielded a PPV of 48% and 50% and a NPV of 92% and 97% for IVC and AA RoR, respectively. CONCLUSION Degree of circumferential involvement of the great vessels is an independent predictor for resection or reconstruction of the IVC or AA at postchemotherapy RPLND. Patients at high risk of great vessel reconstruction should be informed accordingly and have the proper teams available for complex vascular reconstruction.


Urologic Oncology-seminars and Original Investigations | 2018

Perioperative and long-term outcomes after radical cystectomy in hemodialysis patients

Scott Johnson; Zachary L. Smith; Shay Golan; Joseph F. Rodriguez; Shane M. Pearce; Norm D. Smith; Gary D. Steinberg

PURPOSE Patients on hemodialysis have an increased risk of developing advanced stage bladder cancer. They also have a significant risk of noncancer-related mortality. Radical cystectomy (RC) is the standard of care for nonmetastatic muscle-invasive bladder cancer, however little is known regarding outcomes in this population. MATERIALS AND METHODS The United States Renal Disease System database was used to identify all patients on hemodialysis who underwent RC for bladder cancer in the United States between 1984 and 2013. A total of 985 patients were identified for analysis. Perioperative outcomes were evaluated. Competing risks analysis was used to estimate overall and cancer-specific mortality along with factors associated with death. RESULTS Median hospital length of stay was 10 days and 43.1% of patients experienced a complication. Mortality within 30 days was 9.3%. Overall mortality at 1, 3, and 5 years was 51.7%, 77.3%, and 87.9%, respectively. Cancer-specific mortality at 1, 3, and 5 years was 12.3%, 18.4%, and 19.7%, respectively. Age, diabetes, and cerebrovascular disease were independently associated with overall mortality, while performance of urinary diversion was associated with a protective effect. Active smoking was the sole risk factor for cancer-specific mortality. CONCLUSIONS RC in dialysis patients is associated with significant morbidity and mortality, with less than 15% overall survival at 5 years. Older patients, and those with a history of diabetes or cerebrovascular disease, are at an increased risk of mortality.

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Mark Hockenberry

University of Pennsylvania

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Thomas J. Guzzo

University of Pennsylvania

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Alan J. Wein

University of Pennsylvania

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