Biomedical subjects
Publications and source records attributed to S Duke Herrell.
Primary renal carcinoid is a rare tumor, with only 39 cases reported. These tumors have historically been managed with either open partial nephrectomy or open radical nephrectomy. We describe a patient with a primary renal carcinoid tumor successfully treated with laparoscopic partial nephrectomy. To our knowledge, this is the first such case reported.
PURPOSE: Operative experience is important in developing surgical skills and technical competency. There is also emerging evidence directly linking increased surgical volume to patient outcomes. Accordingly, resident training should provide the framework for mastery of complex operations. We evaluated the current urological residency experience in performing adult urinary diversion. MATERIALS AND METHODS: The Accreditation Council for Graduate Medical Education-Residency Review for Urology Operative Log Reports were reviewed from 2000 to 2004 with an emphasis on urinary diversion experience. Resident logs were analyzed specifically for all procedures that included CPT codes for continent and incontinent diversions. The logs were compared by year of training and type of urinary diversion. RESULTS: Overall, the total number of urinary diversions performed by graduating residents from 4-year programs has increased from 2,259 (2000 to 2001) to 4,017 (2003 to 2004). In addition, the mean and median number of urinary diversion cases among residents completing training have remained relatively constant. For graduating urology residents in 2003 to 2004, the mean (median) number of continent urinary diversion and incontinent urinary diversion cases were only 6.7 (3.0) and 9.5 (4), respectively. CONCLUSIONS: Current Accreditation Council for Graduate Medical Education data suggest the average urology resident has limited exposure to urinary diversion in general, and even less experience with more complex continent urinary diversion. These results suggest that many urology residency programs may not have sufficient volume to provide residents with a broad experience in urinary diversion, and alternative strategies to ensure proper training should be explored.
PURPOSE: Radio frequency ablation is a promising modality for treating small renal tumors. Several studies have been published showing its efficacy. A major drawback in the current management of renal tumors with radio frequency ablation is the lack of an effective modality to accurately monitor the progress of the ablation zone in real-time fashion. Previous studies have demonstrated the feasibility of using optical spectroscopy to assess tissue thermal damage, especially in hepatic lesions. We examined the feasibility of this technology in the setting of renal radio frequency ablation. MATERIALS AND METHODS: A portable spectroscopic system was used to acquire in vivo fluorescence and diffuse reflectance spectra from porcine renal tissue undergoing radio frequency ablation in real-time fashion with simultaneous temperature recordings. Fluorescence and diffuse reflectance spectral data were then correlated with various degrees of thermal damage and temperature recordings. RESULTS: The most noticeable change in fluorescence characteristics of renal tissue resulting from thermal coagulation was a strong decrease in fluorescence intensity between 400 and 550 nm. When fully coagulated, a significant increase in diffuse reflectance intensity was observed between 500 and 800 nm. CONCLUSIONS: Optical spectroscopy, specifically fluorescence and diffuse reflectance spectroscopy, differs significantly in porcine renal tissues with varying degrees of thermal damage from radio frequency ablation in an in vivo setting. Future clinical studies with sufficient sample size are required to validate the potential of these findings. Optical diagnostics may prove to be a rapid, noninvasive, low cost option for monitoring the tumor response to radio frequency based ablative techniques. It may be integrated into future radio frequency ablation probes.
OBJECTIVES: To compare intraoperative blood loss, perioperative hematocrit, and transfusion requirements in patients undergoing radical retropubic prostatectomy (RRP) versus robotic-assisted laparoscopic prostatectomy (RALP) by a single surgeon. METHODS: During a 14-month period, 279 patients with localized carcinoma of the prostate were prospectively enrolled in this comparative study. The decision of which surgical approach to use was by patient choice. Of the 279 patients, 176 underwent RALP and 103 underwent RRP. The serum hematocrit was obtained preoperatively and 24 hours postoperatively in all patients. The intraoperative blood loss was recorded, and transfusion requirements were noted. RESULTS: Patients in the RALP group had significantly less intraoperative blood loss compared with the RRP group (mean 191 mL versus 664 mL, P < 0.001). Additionally, the difference in the discharge hematocrit (36.8% versus 32.8%, P < 0.001) and the mean perioperative change in hematocrit (8.0% decrease versus 10.7% decrease, P < 0.001) were significant between the RALP and RRP groups, respectively. Three patients in the RRP group (2.9%) and one in the RALP group (0.5%) required transfusion of blood products (P = 0.14). CONCLUSIONS: The results of this study have shown that RALP is associated with less intraoperative bleeding than RRP, and patients undergoing RALP have a greater serum hematocrit at hospital discharge. The lack of a statistically significant difference in blood transfusion was partially attributable to the low transfusion rate in both groups in this series.
OBJECTIVE: To define changes in the clinical pathway for open radical retropubic prostatectomy (RRP) and to determine their impact on patient care under the indirect influence of minimally invasive prostatectomy after implementing robotically assisted laparoscopic prostatectomy (RALP) at our institution and modifying the collaborative-care pathway. PATIENTS AND METHODS: We retrospectively reviewed the Vanderbilt Prostate Database since the initiation of RALP in May 2003, evaluating those patients who had open RRP. Data were analysed in three consecutive 5-month blocks to determine incremental changes in protocol and outcomes, including complications and re-admissions. RESULTS: Between May 2003 and August 2004, 196 patients had RALP and 183 had RRP. After May 2003, there was a progressive reduction for open RRP in the length of stay from 1.6 to 1.3 days. Analysis also showed an elimination of patient-controlled analgesia, a rapid diet advancement, and drain removal at the surgeon's discretion. There were no major complications after surgery, and three minor complications (1.6%). The rate of re-admission after open RRP was low throughout the study period (seven patients, 3.8%), and did not increase progressively. CONCLUSIONS: The management after open RRP was modified substantially after implementing RALP, with the two clinical pathways now similar. Despite these modifications in the treatment of patients having open RRP there was no increase in morbidity or compromise in patient outcome. Indeed, this study shows the feasibility and safety of a 1-day length of stay for open RRP.
Radical prostatectomy has maintained a cardinal role in the treatment of localized prostate cancer. Robotic-assisted laparoscopic prostatectomy (RALP) has been introduced as a less invasive surgical approach. Available data on RALP versus open approaches were reviewed for surgical and cancer related outcomes. RALP is consistently associated with decreased blood loss and limited postoperative pain and hospital stay. Surgical margins seem similar between most reported series of RALP or open radical prostatectomy. Most intrainstitutional comparisons demonstrate better postoperative continence and potency with RALP, but there is still debate about whether results are superior to radical retropubic prostatectomy in the hands of a highly experienced surgeon. RALP provides outcomes at least comparable, and, in some measures, superior to open surgery. Refinements of instrumentation may provide even better results in the future.
Metastatic tumors are the most common malignancies of the kidney. We report a rare case of isolated metastatic ocular melanoma to the kidney occurring 20 years after diagnosis. A 71-year-old man presented with gross hematuria. He had undergone left enucleation 20 years previously for ocular melanoma and had not required adjuvant therapy. A right upper pole mass was identified on computed tomography and was excised laparoscopically. Pathologic examination revealed metastatic melanoma. Metastatic melanoma to the kidney is rare. A high index of suspicion must be maintained in any patient with a renal mass and a history of a nonrenal malignancy.
Although equipment for performance of robotic-assisted laparoscopic prostatectomy (RALP) is becoming more widely available, few surgeons have acquired the skill and experience necessary to master RALP. A significant issue has been the requisite training and experience (ie, the "learning curve") necessary for a qualified surgeon to become an expert at RALP. The senior author (J.A.S.) has experience with > 2500 radical retropubic prostatectomy (RRP) and > 350 RALP procedures. He assessed his learning curve in achieving expertise with RALP. Because there are no objective measures to define expertise with RALP, achievement of expert status depends on the surgeon's comfort, experience, and results with alternative approaches. Surgeons with extensive experience with open approaches may "set the bar" higher for the learning curve because of expectations. RALP results comparable to those obtained routinely with RRP were not achieved until after > or = 150 procedures. Surgeon comfort and confidence comparable to that with RRP did not occur until after 250 RALP procedures. Defining the learning curve for RALP as the point at which a surgeon could provide outcomes comparable to those obtainable with alternative surgical approaches means that the point varies, depending on the experience and expertise of the surgeon. Surgeons whose sole or dominant experience is with laparoscopic or robotic approaches may have a different perception of the learning curve compared with an experienced open surgeon.
PURPOSE: We describe the development of an innovative device and simple technique for achieving renal parenchymal hypothermia during temporary renal-vascular occlusion for pure laparoscopic partial nephrectomy. MATERIALS AND METHODS: The experiment was conceived in four phases: phase 1: design, manufacture, and testing of the cooling coil; phase 2: proof of concept in nonsurvival porcine surgery; phase 3: experimental porcine survival surgery; and phase 4: human trials. RESULTS: Phase 1 testing confirmed that the coil cooled adequately. During phase 2, the average time required for the renal parenchyma to cool to 15 degrees C was 10.7 minutes, providing an average hypothermic window (15 degrees -24 degrees C) of 30.3 minutes. When recooling was required (parenchymal temperature 24 degrees C), temperatures returned to below 15 degrees C in 3 minutes. The core body temperature dropped an average of 1.48 degrees C. Phase 3 demonstrated an average parenchymal temperature of 11.7 degrees C after a mean cooling time of 9.3 minutes. Temperatures remained below 24 degrees C for an average of 26.7 minutes. Recooling took 3 minutes, and in no procedure did the renal parenchyma temperatures ever return to >24 degrees C prior to reperfusion. The core body temperature dropped an average of 2.20 degrees C. At 48 hours after reperfusion, selective renal-vein blood was obtained for creatinine assay, and the kidneys were harvested. Creatinine results were not statistically different in the treated and control groups. Blinded pathologic analysis confirmed a protective effect using our cooling system. CONCLUSION: Our method is simple, effective, and reproducible.
Hemostasis remains the major challenge in laparoscopic partial nephrectomy (LPN). The TissueLink Floating Ball (TissueLink Medical, Inc., Dover, NH), a high-density monopolar saline-cooled radiofrequency device, is an effective coagulation and dissection device to aid in LPN. Our porcine laboratory model and human clinical experience have shown the device capable of deep renal parenchymal hemostasis without the need for hilar vascular occlusion. We review the excisional technique and initial clinical results, as well as device function, setup, and clinical literature. We find the TissueLink capable of avoiding warm ischemia for excision of selected endophytic masses and, in combination with other techniques, a valuable adjunct for even deeper lesions.
BACKGROUND AND PURPOSE: Laparoscopic intravesical and standard Lich-Gregoir repair have been reported but are technically challenging. Herein, we present our experience with a simplified laparoscopic reimplantation of the ureter to correct vesicoureteral reflux (VUR). MATERIALS AND METHODS: Bilateral VUR was created cystoscopically in six minipigs, as confirmed by a static cystogram 6 weeks later. The laparoscopic extravesical correction of VUR was performed utilizing a full-thickness cystotomy. The ureter was transposed inside the bladder, and a full-thickness bladder closure was performed. No attempt was made to cover the ureter with urothelium. No stents or catheters were utilized postoperatively. Three months after reimplantation, the animals were evaluated with serology, a static cystogram, an intravenous urogram (IVU), and gross pathologic and histopathologic examination. RESULTS: The postoperative cystograms confirmed no reflux in all the reimplanted ureters and residual grade 1 to 3 reflux in the non-reimplanted ureters. All pigs voided normally and were completely continent. Cystoscopic evaluation revealed complete epithelialization over the reimplanted ureter. One surgical complication occurred: the ureter was incorporated into the bladder closure and became obstructed. The IVU in all other pigs demonstrated patent ureters with prompt function. CONCLUSIONS: Laparoscopic reimplantation of the ureter utilizing this modified Lich-Gregoir approach corrected reflux in all animals. The full-thickness bladder incision and intravesical transposition of the ureter greatly simplifies the laparoscopic procedure. This laboratory experience encourages further clinical evaluation in the pediatric population with VUR.
BACKGROUND AND PURPOSE: The optimal surgical tool for laparoscopic partial nephrectomy (LPN) would permit resection of lesions that penetrate relatively deeply and achieve hemostasis while allowing accurate viewing of the margins of the lesion, identification of the collecting system, control of both arteries and veins, and sealing of the collecting system. We hypothesized that the TissueLink Floating Ball (TissueLink, Inc.) might provide a simple, "pure" method of LPN. MATERIALS AND METHODS: Ten adult female pigs (30-50 kg) underwent LPN of the left kidney with the TissueLink operating at 70 to 80 W as the sole means of hemostasis. Operative time, estimated blood loss (EBL), and specimen weight and characteristics, were recorded. On postoperative day 7, an intravenous urogram was carried out, and an open partial nephrectomy and surface treatment were performed on the other side with the TissueLink and intraparenchymal temperature monitoring. RESULTS: All LPNs were performed without complications with an average operating time of 148 minutes and a mean estimated blood loss of 49 mL. The urograms performed at postoperative day 7 demonstrated prompt excretion and no evidence of urinary extravasation or hydronephrosis. At harvest, all eight kidneys in which the collecting system had been entered showed evidence of localized urine leak. No evidence of retroperitoneal hematoma was noted, and all renal arteries and veins were patent and with good flow. The resected edge showed a gross 2 to 3 mm of flat, whitish discoloration and a well-demarcated edge. During the open partial nephrectomy, significant temperature variations were noted according to the distance from the point of application of the TissueLink. Pathologic examination of the acute specimens demonstrated altered cytoplasmic and nuclear staining in tubules extending approximately 6 to 8 mm from the treated surface. In contrast, the kidney that had been left in situ after LPN demonstrated overt cortical necrosis (coagulated necrosis), bordered by cortical scarring with apparent dystrophic calcifications at the resection edge from the previous partial nephrectomy. Tubular atrophy was obvious, with interstitial fibrosis and interstitial inflammation. A well-demarcated zone of several millimeters of tissue was evident on gross examination. CONCLUSIONS: The saline-cooled monopolar radiofrequency dissector (TissueLink) is a valuable adjunct for LPN. The device provided excellent hemostatic control with resection of as much as 40% of the renal parenchyma. Our initial observations of the device in the laboratory and in clinical use led us to develop a successful technique for its use for deep parenchymal resection, which is described in detail.
PURPOSE: Benefits of minimally invasive procedures include decreased hospitalization and recovery times. Decreased length of stay (LOS) improves hospital efficiency and decreases costs. However, decreasing the LOS at the expense of patient care and satisfaction is not acceptable. A clinical pathway (CP) with structured order sets and imaging was developed for patients undergoing laparoscopic pyeloplasty. This pathway includes a cascade of activities managed closely by the health care team. This study assesses the safety and patient satisfaction with this clinical pathway. MATERIALS AND METHODS: We reviewed all adult pyeloplasties (39) completed laparoscopically since November 2001. All patients were managed according to the CP developed for the laparoscopic pyeloplasty procedure. The length of stay was measured in days. Patient satisfaction was assessed with a standardized questionnaire. Any readmissions or emergency room visits were documented. RESULTS: The mean length of stay was 1.10 days. Of 39 patients 37 (94%) were discharged home on postoperative day 1. One patient with severe postoperative pain required intravenous analgesia. She had undergone complex upper tract reconstruction and stayed a total of 4 days. One patient, who had a previous failed endopyelotomy, remained 2 days for persistent nausea. No patients sought emergency room consultation and there were no readmissions. Of 39 patients 34 (87%) completed the questionnaire and satisfaction was high. CONCLUSIONS: The implementation of a CP at our institution has standardized patient care in this population and decreased LOS in comparison to the literature. This improves bed use and hospital efficiency while maintaining a high degree of patient satisfaction. We conclude that with intensive patient care and education most patients undergoing laparoscopic pyeloplasty may be discharged home safely on postoperative day 1.
PURPOSE: Laparoscopic prostatectomy, whether or not coupled with robotic assistance, is often considered less invasive than open radical retropubic prostatectomy (RRP). Minimal postoperative pain has been reported following robot assisted laparoscopic prostatectomy (RALP) but there have been few comparative studies with RRP. We compared perioperative narcotic use and patient reported pain in a prospective patient series. MATERIALS AND METHODS: Between June 2003 and May 2004, 314 patients underwent radical prostatectomy at our institution, including RALP in 159, RRP in 154 and conversion in 1. All patients were treated on a postoperative clinical pathway that included 30 mg ketorolac intravenously immediately postoperatively, followed by 15 mg intravenously every 6 hours. No regional anesthesia (epidural/spinal) narcotics or patient controlled analgesic pumps were used. All narcotic use was converted to morphine sulfate equivalents for purpose of analysis. A Likert scale of 0 to 10 was used to assess pain on the day of surgery, and on postoperative days 1 and 14. RESULTS: The total mean morphine sulfate equivalent +/- SD in patients in the RALP and RRP groups was low and, when corrected for length of stay, it was not statistically different (22.41 +/- 1.13 vs 23.01 +/- 1.16 mg, p = 0.72). Mean Likert pain perception scores were low at all time points in the RALP and RRP groups but statistically lower on the day of surgery in the RALP cohort (2.05 +/- 1.99 vs 2.60 +/- 2.25, p = 0.027). Patient reported mean pain scores were almost identical for RALP vs RRP on postoperative days 1 (1.76 +/- 1.87 vs 1.73 +/- 1.77, p = 0.880) and 14 (2.51 +/- 1.91 vs 2.42 +/- 1.84, p = 0.722). CONCLUSIONS: Perioperative narcotic use and patient reported pain are low regardless of the surgical approach used for radical prostatectomy. RALP did not provide a clinically meaningful decrease in pain compared with RRP, primarily because of the low pain scores reported in each group. Outcomes other than pain will ultimately determine the role of laparoscopic radical prostatectomy and RALP.
PURPOSE: Promising results of optical signals have been reported in the literature for the diagnosis of Barrett's esophagus, oral cavity lesions, brain tumor margins, cervical intraepithelial neoplasia, skin cancer and bladder cancer. The potential usefulness of these techniques in renal tissues and neoplasms has not been described to date. This initial study examined the feasibility of using fluorescence and diffuse reflectance spectroscopy to differentiate between malignant and benign renal tissues. MATERIALS AND METHODS: An ex vivo study was conducted to identify optical characteristics of various renal tissue types. Pathologically confirmed benign and malignant renal samples were obtained from nephrectomy specimens from patients undergoing radical nephrectomy. Fluorescence and diffuse reflectance spectra were measured from benign and malignant renal tissues. RESULTS: All renal tissues, malignant or benign, contain 2 primary emission peaks-a strong one at approximately 285 nm excitation, approximately 340 nm emission (Peak A), and a weak one at approximately 340 nm excitation, approximately 460 nm emission (Peak B). Peak A of normal renal tissue typically locates at the shorter excitation wavelength region than that of malignant tissue. The intensity of Peak B from benign tissues tends to be greater than that from malignant renal tissues. Diffuse reflectance intensities from malignant renal tissues between 600 and 800 nm are markedly greater than those from normal renal tissue. Empirical discrimination algorithms developed based on selected fluorescence and diffuse reflectance spectral characteristics yields accurate differentiation between benign and malignant renal tissues. CONCLUSIONS: Highly accurate differentiation between normal human renal tissues and renal cell cancers is feasible using combined fluorescence and diffuse reflectance spectroscopy in an ex vivo setting. If successful in future clinical studies, optical spectroscopy could aid in margin detection and tissue discrimination while performing nephron sparing surgery.
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Approximately 33% of patients with renal cell carcinoma will present with metastases. Patients have a reported 35% 5-year survival rate in instances in which nephrectomy and surgical resection of a solitary metastasis have been performed. Laparoscopic partial nephrectomy has become an increasingly viable option in the treatment of some renal cancers. We report a case in which a patient had a solitary lung nodule in the workup for a renal mass. This patient underwent combined thoracoscopic and laparoscopic resection of both the lung nodule and the renal mass in the same setting.
The flexible ureteroscope has revolutionized the diagnosis and treatment of the entire upper urinary tract. Endoscopic tools have evolved, providing the surgeon with the armamentarium necessary to treat many different pathologic processes. Almost all renal calculi can be treated with retrograde ureteroscopy. The fragility of these new endoscopes is a concern, and great care must be taken when using them. With good technique and proper use of instruments, their working life can be extended.