Biomedical subjects

Sam B Bhayani

Publications and source records attributed to Sam B Bhayani.

At least 19 recordsLinked to original sources

PubMed2006

Minimally invasive approaches to localized prostate carcinoma.

Prostate cancer is an increasing medical problem. Radical prostatectomy and radiation therapy are effective treatments, but have the risk of significant morbidity. Clinicians have strived to develop new modalities of treatment that can maintain the excellent treatment outcomes of radical prostatectomy, but diminish the morbidity. Improved instrumentation, optics, and robotic technology have allowed the application of laparoscopic techniques to radical prostatectomy. Patients can have less blood loss and expect more rapid recovery. Intermediate oncologic outcomes appear similar to radical prostatectomy with good functional results. Cryotherapy and HIFU are tissue ablative approaches rather than extirpative approaches to prostate cancer treatment. They attempt to use nonsurgical methods to treat prostate cancer with the hope of providing oncologic control comparable to surgery and radiation while minimizing morbidity.

Cryosurgery↗

PubMed2006

Pathological features of renal neoplasms classified by size and symptomatology.

PURPOSE: We examined the relationship between tumor size and pathological findings in a contemporary series of surgical renal lesions and we characterized the relationship of incidental and symptomatic tumors to pathological findings. MATERIALS AND METHODS: We retrospectively reviewed the records of patients treated surgically for renal lesions suspicious for malignancy between March 2000 and May 2005. Specimens were examined for a gross and microscopic description. Statistical analysis was used to determine the correlation of size and symptomatology. RESULTS: A total of 349 renal masses from 331 patients were identified. Of the 349 renal masses 56 (16.0%) were benign, 289 (82.8%) were renal cell carcinoma and 4 (1.1%) were other malignancies. The percent of malignant tumors increased from 72.1% for those less than 2 cm to 93.7% for those greater than 7 cm (OR 1.39, 95% CI 1.17 to 1.65). Of the 349 renal masses 258 (73.9%) were discovered incidentally and 91 (26.1%) were symptomatic. Mean size of incidental and symptomatic tumors was 3.7 and 6.2 cm, respectively (p < 0.001). When comparing T1 incidental and symptomatic tumors, there was no significant difference in the overall frequency of malignancy. When comparing T2 incidental and symptomatic tumors, the groups had similar malignancy rates (90.9% and 100%, respectively, p = 0.16). However, symptomatic lesions showed an increased incidence of high grade malignancy (78.4% vs 40.9%, p = 0.012). CONCLUSIONS: Smaller renal tumors are more likely to be benign or be a lower grade of malignancy. T1 renal tumors are more likely to be detected incidentally than T2 tumors. When T1 incidental and symptomatic tumors were compared, there was no difference between the malignancy rates. However, when T2 incidental and symptomatic tumors were compared, symptomatic tumors were more likely to be high grade malignancy.

Adenoma, Oxyphilic↗

PubMed2006

How does the radiographic size of a renal mass compare with the pathologic size?

OBJECTIVES: To investigate the relationship between the radiographic size on computed tomography and the pathologic size of renal tumors. METHODS: The records of 126 patients with a renal lesion suspicious for malignancy and with preoperative computed tomography performed 60 days or less before surgery at our institution were reviewed. The clinical size was defined as the largest diameter of the tumor seen on computed tomography and the pathologic size was defined as the largest diameter seen at pathology. The clinical and pathologic sizes were compared by size range and primary tumor stage. RESULTS: A total of 133 tumors from 126 patients were identified. Of the 133 tumors, 120 (90.2%) were renal carcinoma. The clinical and pathologic size for all 133 tumors was not significantly different (4.5 versus 4.1 cm, P = 0.35). The average clinical tumor size was larger than the pathologic tumor size for all sizes, except for 7 cm and greater. The difference reached statistical significance in all ranges from 1 to 5 cm. The largest size difference was seen for tumors 4 to 5 cm, for which the average clinical size was 0.87 cm larger than the average pathologic size (P = 0.025). CONCLUSIONS: Preoperative computed tomography imaging may slightly overestimate the pathologic size of renal tumors in certain size ranges. In pathologic Stage T1a tumors, the clinical tumor size was significantly larger than the pathologic stage (P = 0.009). The difference between the clinical and pathologic tumor size was greatest for tumors 4 to 5 cm. These results may affect decisions to perform nephron-sparing surgery in certain patients.

Adult↗

PubMed2006

Trends in nephron-sparing surgery for renal neoplasia.

OBJECTIVES: To determine the extent that laparoscopy has replaced open surgery for nephron-sparing surgery in a mature laparoscopic environment. METHODS: The records of all patients at Washington University who underwent nephron-sparing surgery for localized renal masses from 1999 to 2003 were examined for clinical and pathologic information. Information regarding the mass size, surgery type performed, and surgeon training was obtained. RESULTS: A total of 271 patients underwent nephron-sparing surgery from January 1999 to December 2003. During the study period, the total number of partial nephrectomies increased from 33 per year to 91 per year. The proportion of laparoscopic partial nephrectomy increased from 3% of total cases to 56% of total cases. Open partial nephrectomy decreased from 97% of cases to 24% of cases; however, the absolute number of open partial nephrectomies only decreased from 32 to 22 per year. Laparoscopic cryoablation increased from 0% of cases to 20% of cases. Endourologists increased their frequency of performing open partial nephrectomy, and oncologists increased their frequency of performing laparoscopic renal surgery. CONCLUSIONS: Laparoscopic nephron-sparing surgery has not completely replaced open partial nephrectomy for low-stage renal neoplasia; however, the number of laparoscopic partial nephrectomies has increased rapidly in recent years. Laparoscopic approaches are being performed by all urologists treating renal malignancies at our institution and this reflects changes in the surgical treatment of renal cancer.

Adult↗

PubMed2006

Exploration for hemorrhage following laparoscopic renal surgery: intraoperative findings.

PURPOSE: Bleeding after surgery is a rare but potentially life threatening complication. We reviewed operative and postoperative clinical features in patients who required surgical exploration secondary to hemorrhage following laparoscopic renal procedures. MATERIALS AND METHODS: We retrospectively reviewed the records of patients undergoing laparoscopic renal surgery between January 1996 and September 2004. Nine of 1,123 patients (0.8%) underwent early exploration for bleeding within 5 days of surgery. RESULTS: Two groups were identified. Group 1 consisted of 4 patients who underwent early exploration at less than 10 hours after surgery and had arterial bleeding. Group 2 consisted of 5 patients who underwent exploration a mean 38 hours after surgery and in whom no bleeding source was identified. Group 1 patients had pronounced hypotension with systolic blood pressure 70 to 79 mmHg and hematocrit decreases (mean 10.5%) in a short time course before repeat exploration (mean 4.5 hours). Arterial bleeding was identified in the hilum and adrenal bed. Group 2 patients demonstrated a decrease in hematocrit from an initial mean of 28.3% to 22.5% with tachycardia and mild hypotension (systolic blood pressure 90 to 99 mmHg). On exploration group 2 patients had diffuse oozing. Mean hospital stay in group 1 was 8 days (range 4 to 9) vs 12 (range 6 to 24) in group 2. CONCLUSIONS: Early hemodynamic instability after laparoscopic renal surgery is likely to indicate a discrete arterial bleeding source from the hilum or adrenal bed, requiring surgical control. In patients who underwent exploration after a delayed bleeding presentation no discrete source was found intraoperatively. Therefore, it is unclear whether these patients benefited from surgical exploration.

Adult↗

PubMed2006

A prospective comparison of robotic and laparoscopic pyeloplasty.

OBJECTIVE: To determine whether robotic-assisted pyeloplasty (RLP) has any significant clinical or cost advantages over laparoscopic pyeloplasty (LP) for surgeons already facile with intracorporeal suturing. SUMMARY BACKGROUND DATA: LP has become an established management approach for primary ureteropelvic junction obstruction. More recently, the da Vinci robot has been applied to this procedure (RLP) in an attempt to shorten the learning curve. Whether RLP provides any significant advantage over LP for the experienced laparoscopist remains unclear. METHODS: Ten consecutive cases each of transperitoneal RLP and LP performed by a single surgeon were compared prospectively with respect to surgical times and perioperative outcomes. Cost assessment was performed by sensitivity analysis using a mathematical cost model incorporating operative time, anesthesia fees, consumables, and capital equipment depreciation. RESULTS: The RLP and LP groups had statistically indistinguishable demographics, pathology, and similar perioperative outcomes. Mean operative and total room time for RLP was significantly longer than LP by 19.5 and 39.0 minutes, respectively. RLP was much more costly than LP (2.7 times), due to longer operative time, increased consumables costs, and depreciation of the costly da Vinci system. However, even if depreciation was eliminated, RLP was still 1.7 times as costly as LP. One-way sensitivity analysis showed that LP operative time must increase to almost 6.5 hours for it to become cost equivalent to RLP. CONCLUSIONS: For the experienced laparoscopist, application of the da Vinci robot resulted in no significant clinical advantage and added substantial cost to transperitoneal laparoscopic dismembered pyeloplasty.

Clinical Competence↗

PubMed2005

Pain control requirements for percutaneous ablation of renal tumors: cryoablation versus radiofrequency ablation--initial observations.

PURPOSE: To retrospectively compare the pain control requirements of patients undergoing computed tomography (CT)-guided percutaneous radiofrequency (RF) ablation with those of patients undergoing CT-guided percutaneous cryoablation of small (< or = 4-cm) renal tumors. MATERIALS AND METHODS: The study was HIPAA compliant and received institutional review board exemption; informed consent was not required. Medical and procedure records of patients who underwent RF ablation and cryoablation of renal tumors from June 19, 2003, to February 28, 2004, were retrospectively reviewed for clinical data, tumor characteristics, and anesthesia information. During the study period, 10 men (mean age, 66.5 years) underwent cryoablation of 11 renal lesions, and 14 patients (11 men, four women; mean age, 68.1 years) underwent RF ablation of 15 renal tumors. Analgesic and sedative requirements during the procedure were compared. Standard anesthesia consisted of 5 mL of 1% lidocaine injected locally, and conscious sedation consisted of 50 microg of fentanyl and 1 mg of midazolam administered intravenously. The Fisher exact test and Student t test were used to compare clinical factors and drug requirements between the two groups. RESULTS: There was no difference in terms of patient demographics, tumor diameter, or distribution of central versus noncentral lesions between the two groups. Cryoablation was associated with a significantly lower dose of fentanyl (165.0 microg [RF group] vs 75.0 microg [cryoablation group]; P < .001) and midazolam (2.9 mg [RF group] vs 1.6 mg [cryoablation group]; P = .026). In the RF group, one patient required general anesthesia, one patient required supplemental narcotics (5 mg of oxycodone) and sedatives (1 mg lorezapam), and one patient became apneic for a brief interval after receiving additional narcotics for pain during the procedure. An additional RF session was terminated early in one patient because of pain, and further medication could not be administered owing to bradycardia. No patients in the cryoablation group required any additional or alternate anesthetics. CONCLUSION: Image-guided percutaneous cryoablation of small (< or = 4-cm) renal lesions appears to require less analgesia than RF ablation. Prospective trials with validated pain scales are needed to examine this further.

Aged↗

PubMed2005

Neuromuscular complications after percutaneous radiofrequency ablation of renal tumors.

Neuromuscular complications after percutaneous renal tumor ablation have not been previously reported. In a series of 48 patients undergoing percutaneous ablation, 3 of our patients had neuromuscular complications. One patient developed permanent flank laxity and two had transient paresthesias. Neuromuscular complications are uncommon, but may occur with percutaneous renal ablative surgery.

Aged↗

PubMed2005

Laparoscopic retroperitoneal lymph node dissection: duplication of open technique.

Laparoscopic retroperitoneal lymph node dissection has been used to stage germ cell testicular cancer. Since its initial description, this minimally invasive procedure has evolved into a therapeutic operation that adheres to established strict oncologic principles. A modified template dissection that fully duplicates the open technique is now routinely performed at our institution. We describe and show in the accompanying video segments a laparoscopic modified template dissection.

Humans↗

PubMed2005

Laparoscopic temporary packing for hemostasis.

Control of bleeding from the renal parenchyma remains one of the challenges of laparoscopic partial nephrectomy. If adjuvant measures fail, packing of the surgical bed may achieve hemostasis. We report a novel series of temporary laparoscopic packing of the surgical bed with minimally invasive kidney surgery. Technique and potential complications are also discussed.

Aged↗

PubMed2005

Pure laparoscopic radical heminephrectomy and partial isthmusectomy for renal cell carcinoma in a horseshoe kidney: case report and technical considerations.

Laparoscopic surgery of the horseshoe kidney has been limited to benign conditions, hand assistance, and retroperitoneal approaches for small tumors. In this case, we describe a pure transperitoneal approach to heminephrectomy for a large renal cell carcinoma. The operative considerations include identification of all arterial branches and careful isthmus dissection. Preoperative angiography may aid surgical planning. A pure transperitoneal approach to cancer surgery of the horseshoe kidney is effective.

Carcinoma, Renal Cell↗

PubMed2005

Extrarenal vascular anatomy of kidney: assessment of variations and their relevance to partial nephrectomy.

OBJECTIVES: To evaluate the feasibility of selective segmental artery clamping during partial nephrectomy. METHODS: Precise extraparenchymal renal hilar dissection was performed on 73 fixed cadaveric kidneys. The surgical accessibility to clamping of each presegmental and segmental artery from the anterior and posterior approaches was determined on the basis of vessel length, position within the renal hilum, and degree of overlying collecting system or venous structures. RESULTS: The vascular anatomy consisted of zero, one, or two presegmental arteries (extrarenal main renal artery branches that split into two or more segmental arteries) in 49.3%, 31.5%, and 19.2% of the kidneys, respectively. From a posterior approach, the posterior segmental artery was accessible to isolated clamping in 81.8% of the kidneys (segmental accessibility rate) and was accessible to clamping at the presegmental level in 12.7% (presegmental accessibility rate) for a total accessibility rate of 90.9%. The total accessibility rate for the inferior segmental artery was 88.5% from an anterior and 66.7% from a posterior surgical approach. The apical artery total accessibility rate was 72.3% and 40.5% from an anterior and posterior approach, respectively. The corresponding middle and superior segmental artery total accessibility rates were 50.8% and 32.8%. CONCLUSIONS: In this cadaveric model, hilar dissection and clamping of the renal segmental arteries is anatomically feasible in most cases. Posterior and polar tumors will likely be more amenable to segmental vascular control. Selective segmental vascular control may offer the benefits of total hilar control while reducing overall renal ischemic injury.

Cadaver↗

PubMed2005

Complete daVinci versus laparoscopic pyeloplasty: cost analysis.

BACKGROUND AND PURPOSE: Computer-assisted pyeloplasty with the daVinci system is an emerging technique to treat ureteropelvic junction (UPJ) obstruction. A relative cost analysis was performed assessing this technology in comparison with purely laparoscopic pyeloplasty. PATIENTS AND METHODS: Eight patients underwent computer-assisted (daVinci) dismembered pyeloplasty (CP) via a transperitoneal four-port approach. They were compared with 13 patients who underwent purely laparoscopic pyeloplasty (LP). All patients had a primary UPJ obstruction and were matched for age, sex, and body mass index. The cost of equipment and capital depreciation for both procedures, as well as assessment of room set-up time, takedown time, and personnel were analyzed. Surgeons and nursing staff for both groups were experienced in both laparoscopy and daVinci procedures. One- and two-way financial analysis was performed to assess relative costs. RESULTS: The mean set-up and takedown time was 71 minutes for CP and 49 minutes for LP. The mean length of stay was 2.3 days for CP and 2.5 days for LP. The mean operating room (OR) times for CP and LP were 176 and 210 minutes, respectively. There were no complications in either group. One-way cost analysis with an economic model showed that LP is more cost effective than CP at our hospital if LP OR time is <338 minutes. With adjustment to a volume of 500 daVinci cases/year, CP is still not as cost effective as LP. Two-way sensitivity analysis shows that in-room time must still be <130 minutes and yearly cases must be >500 to obtain cost equivalence for CP. CONCLUSIONS: Perioperative parameters for CP are encouraging. However, the costs are a clear disadvantage. In our hospital, it is more cost effective to teach and perform LP than to perform CP.

Adult↗

PubMed2005

Health related quality of life before and after laparoscopic radical prostatectomy.

PURPOSE: The viability of laparoscopic radical prostatectomy (LRP) as a surgical treatment for prostate cancer depends on oncological and health related quality of life (HRQOL) outcomes. We present a prospective assessment of HRQOL in 122 patients before and after LRP using the validated Expanded Prostate Cancer Index Composite (EPIC) questionnaire. MATERIALS AND METHODS: EPIC data were collected preoperatively, and at 3, 6 and 12 months after LRP, and all were normalized to patient preoperative baseline responses. RESULTS: Using traditional single question responses, 93.4% of patients were continent (0 to 1 pads) at postoperative month 12. Of previously potent men who underwent bilateral nerve sparing 78.9% reported engaging in sexual intercourse within postoperative year 1. However, EPIC domain scores provided a more comprehensive assessment of functional outcomes. For the urinary incontinence subdomain, the majority of functional recovery was achieved by postoperative month 6, reaching a 74% return to baseline on average. In contrast, recovery of the sexual function subdomain continued throughout postoperative year 1 (to a mean of 64%). Recovery of sexual function was not significantly affected by age or preoperative potency status, although the extent of nerve sparing was a significant predictor of outcome (mean recovery to 75% of baseline for bilateral vs 36% for no nerve sparing at 12 months, p = 0.005). CONCLUSIONS: Nerve sparing LRP provides satisfactory first year HRQOL outcomes when assessed with a validated instrument. The time course and extent of functional recovery documented in this prospective study may prove useful for patient counseling before LRP.

Humans↗

PubMed2005

Pathological stage does not alter the prognosis for renal lesions determined to be stage T1 by computerized tomography.

PURPOSE: Pathological stage has been the most widely used prognosticator for evaluating surgically managed cases of renal cell carcinoma. Minimally invasive surgical approaches are being increasingly used to treat small masses for which traditionally pathological information is lacking (morcellation) or absent (radio frequency ablation or cryoablation). Preoperative cross-sectional imaging by computerized tomography (CT) or magnetic resonance imaging has been used to stage renal tumors clinically but it can lead to variances with traditional pathological staging systems, particularly with respect to microscopic invasion beyond the renal capsule. In this study we assessed whether radiographically staged clinical T1 lesions that were pathological T1 behave differently than those that were clinical stage T1 and up staged to pT3a. MATERIALS AND METHODS: The records of 296 patients who underwent surgical treatment for renal cell carcinoma at The Johns Hopkins Hospital between 1990 and 1999 were retrospectively reviewed. All patients had undergone preoperative CT or magnetic resonance imaging, which was used to assign a clinical stage and size (largest diameter) to each tumor in accordance with the 1997 TNM staging system. Following surgical resection pathological stage, size and tumor grade were determined. Only the 186 patients with clinical T1 tumors were included in this analysis. RESULTS: Of the 186 patients who were clinically found to have T1 lesions 125 (67%) had pathological T1 and 57 (31%) had pathological T3a lesions. All surgical margins and lymph nodes were negative at surgical resection. Mean tumor size +/- SD was 3.9 +/- 1.5 cm for pT1 lesions and 3.8 +/- 1.5 cm for pT3a lesions. When comparing these pathological groups using Kaplan-Meier analysis, 5-year recurrence-free survival was not statistically different in patients with pT1 and pT3a lesions (90.6 and 97.5%, respectively). CONCLUSIONS: Patients in whom the initial classification of T1 renal cell carcinoma by CT was up graded to T3a on pathological analysis (invasion of fat within Gerota's fascia) showed the same recurrence-free survival rate as patients with pathologically confirmed T1 lesions. Thus, smaller tumors (less than 7 cm) that are up graded to T3a based on capsule invasion behave much like T1 tumors and exact pathological T staging does not appear to impact overall survival.

Carcinoma, Renal Cell↗

PubMed2005

Exploring the learning curve, pathological outcomes and perioperative morbidity of laparoscopic partial nephrectomy performed for renal mass.

PURPOSE: We investigated the learning curve, pathological results and perioperative morbidity of laparoscopic partial nephrectomy (LPN). MATERIALS AND METHODS: The records of all LPN cases at our institution between January 1999 and March 2004 were reviewed. Of 223 cases 217 (97.3%) were performed for an enhancing renal mass. RESULTS: Mean tumor size was 2.6 cm (range 1 to 10) and 95.4% of patients had a normal contralateral kidney. Transient vascular control was performed in 75.1% of cases. Mean operative time (186 minutes) decreased with surgeon experience (p = 0.003) but was independent of tumor size (p = 0.964). Mean warm ischemia time (27.6 minutes) depended on tumor size (p = 0.005) but not on experience (0.964). Mean blood loss was 385 cc and the perioperative transfusion rate was 6.9%. Postoperative complications occurred in 23 cases (10.6%) with the most common being ileus (1.8%), bleeding (1.8%) and urinary leakage (1.4%). Although the mean serum creatinine change after LPN was a function of tumor size (p <0.001), it was clinically insignificant (0.13 mg/dl). No significant relationship was observed between warm ischemia time and creatinine change (p = 0.262). The final pathological evaluation revealed renal cell carcinoma in 144 patients (66.4%) and the overall positive margin rate was 3.5%. Only 2 renal cell carcinoma recurrences in the operated kidney (1.4%) were identified (mean followup +/- SD 24 +/- 12 months). CONCLUSIONS: LPN is an effective approach for treating small renal masses with low perioperative morbidity. Contrary to previous reports, more than 30% of the enhancing renal lesions excised in this series were found to be benign on final pathological evaluation.

Adult↗

PubMed2005

Percutaneous radio frequency ablation of renal masses: results at a 2-year mean followup.

PURPOSE: We describe our experience with and results of percutaneous computerized tomography guided radio frequency ablation (RFA) for small (less than 4 cm) renal tumors at a 2-year mean followup. MATERIALS AND METHODS: A total of 49 patients (60 renal tumors) with a mean age of 63.9 years underwent percutaneous RFA. Indications for RFA were severe comorbidities or previous abdominal surgery precluding operative management, or hereditary conditions predisposing to multiple tumor recurrence. Persistent enhancement on initial followup imaging was considered incomplete treatment and all such patients underwent biopsy and were offered repeat RFA. Enhancement or enlargement on subsequent imaging was considered tumor recurrence and these patients were counseled regarding further therapy. RESULTS: Three patients (4 tumors) were excluded from evaluation due to death from unrelated causes or loss to followup. A total of 46 patients (56 tumors) were available for evaluation at a mean followup of 27.5 months (range 12 to 48). Six tumors were incompletely treated with the first RFA and successfully treated with a second session. Recurrences after successful initial treatment were seen in 3 of 46 patients. These recurrences developed 24, 25 and 31 months following RFA, respectively, and all occurred in patients with a central tumor of 3.0 cm or greater. Overall local control was achieved in 94.6% of tumors (53 of 56). CONCLUSIONS: RFA is an emerging alternative treatment modality for small renal tumors. Larger (greater than 3.0 cm) central tumors represent unique technical challenges, making these tumors more prone to recurrence. Long-term followup is needed to establish the oncological durability of this technique.

Adult↗

PubMed2005

Evaluation of intra-abdominal pressures and gas embolism during laparoscopic partial nephrectomy in a porcine model.

PURPOSE: Gas embolization is a well documented complication of laparoscopic surgery. We evaluated the association of gas embolization with increased intra-abdominal pressure (IAP) in the porcine model during laparoscopic partial nephrectomy with real-time transesophageal echocardiography. MATERIALS AND METHODS: Eight domestic pigs weighing 143 to 162 pounds underwent unilateral transperitoneal laparoscopic heminephrectomy with renal artery clamping with varied IAPs. The renal vein was not clamped, allowing the exposure of venous tributaries to the pneumoperitoneum. IAP was increased in 5 mm Hg increments in 4 pigs each by 1) insufflation pressure adjustment to a maximum of 30 mm Hg and 2) intermittent application of an argon beam coagulator (ABC) to the cut kidney surface. Transesophageal echocardiography was used to monitor embolism. RESULTS: None of the 4 animals subjected to increased CO2 insufflation pressure (maximum 30 mm Hg) demonstrated gas embolization during partial nephrectomy. The ABC caused gas embolization during partial nephrectomy at an IAP of 30 to 50 mm Hg in 4 animals. The volume of embolized gas was 4 to 20 ml. None of the animals showed intraoperative hemodynamic compromise. CONCLUSIONS: Gas embolization was not seen during laparoscopic partial nephrectomy with typical insufflation pressures. The ABC can rapidly increase IAP and cause argon embolization at IAPs greater than 30 mm Hg. Prophylactic maneuvers to prevent gas embolization, such as intra-abdominal venting or renal vein clamping, should be considered when applying the ABC.

Animals↗