Biomedical subjects

Raju Thomas

Publications and source records attributed to Raju Thomas.

32 records · Page 2Linked to original sources

PubMed2005

Concomitant management of renal calculi and pelvi-ureteric junction obstruction with robotic laparoscopic surgery.

OBJECTIVE: To present technical recommendations for robotic-assisted laparoscopic pyeloplasty (RALP) and stone extraction, as patients with kidney stones proximal to a pelvi-ureteric junction obstruction (PUJO) present a technical challenge, and have traditionally been managed with open surgery or percutaneous antegrade endopyelotomy. PATIENTS AND METHODS: From November 2002 to April 2005, 55 patients had RALP for PUJO; eight of these had concomitant renal calculi. Stone burden and location were assessed with a preoperative radiological examination. Before completing the PUJO repair, one robot working arm (cephalad one) was temporarily undocked to allow passage of a flexible nephroscope into the renal pelvis and collecting systems under direct vision. Stones were extracted with graspers or basket catheters and removed via the port. The surgical-assistant port in the subxiphoid area was used to introduce laparoscopic suction and other instruments. RESULTS: The Anderson-Hynes dismembered pyeloplasty was the preferred reconstructive technique in all patients. Operations were completed robotically with no conversions to open surgery. All patients were rendered stone-free, confirmed by imaging, and there were no intraoperative or delayed complications during a mean (range) follow-up of 12.3 (4-22) months. The mean operative time was 275.8 min, 61.7 min longer than in patients who did not have concomitant stone removal. CONCLUSIONS: Concurrent stone extraction and PUJO repair can be successful with RALP. Operative times are longer than in patients with isolated PUJO repair, but this is to be expected as there is an additional procedure.

Adolescent↗

PubMed2004

Use of the LigaSure vessel sealing device in laparoscopic living-donor nephrectomy.

BACKGROUND: Laparoscopic living-donor nephrectomy has gained acceptance within the transplant community. The technique requires advanced laparoscopic techniques, and great care must be taken to ensure safety of the operation for the donor and transplantability of the donor kidney. Minimizing the risk of bleeding and trauma to the kidney are important features of a successful living-donor nephrectomy. Improved laparoscopic instrumentation has afforded greater safety and efficacy through technical advances. METHODS: The LigaSure device was used in 124 consecutive living-donor nephrectomies beginning in 1999. A transplant database was reviewed for operative statistics including intraoperative blood loss and operating time. RESULTS: The LigaSure device was used to dissect and seal all venous and arterial branches. Estimated blood loss was 90 +/- 53 mL. A suction device was required in only 40 (32%) of the cases. No patient experienced postoperative bleeding. There were two donor complications: one incisional hernia and one ileus. All kidneys functioned immediately upon reperfusion. CONCLUSIONS: The LigaSure device is an extremely effective tool for obtaining hemostasis by sealing both venous and arterial branches of the major renal vessels. This is also effective in sealing lymphatic tissues and thereby facilitating dissection. Avoiding the use of metallic clips simplified final division of the renal artery and vein. As with any laparoscopic instrument, the anatomic geometry of the operative field may limit use based upon port placement.

Adolescent↗

PubMed2004

Retrograde ureteroscopic endopyelotomy.

Several different procedures can be used to treat UPJ obstruction. Retrograde ureteroscopic endopyelotomy provides a safe and adequate first line of treatment for this condition. With the advent of smaller ureteroscopes and ancillary devices, this technique has evolved to include children. Adherence to strict endourologic principles and direct visualization make retrograde ureteroscopic endopyelotomy a safe and effective treatment modality. This procedure represents an extension of the basic endoscopic skills of the urologist, creating a short learning curve and wide margin of safety.

Clinical Trials as Topic↗

PubMed2004

Donor nephrectomy in the era of hand-assisted laparoscopic urologic surgery.

Living-donor nephrectomy has traditionally been performed through a flank incision with or without rib resection or by an anterior extraperitoneal incision, both of which reduce the willingness of potential donors to undergo the procedure. The first successful human laparoscopic donor nephrectomy was reported in 1995. In order to reduce warm ischemia and operative time and to make the operation safer and easier, some laparoscopic surgeons have used hand assistance. The authors describe their technique for this operation and review the results.

Equipment Design↗

PubMed2004

Laparoscopic partial nephrectomy of solid renal masses without hilar clamping using a monopolar radio frequency device.

PURPOSE: Partial nephrectomy is currently recommended for most amenable solid renal tumors, especially if they are exophytic and less than 4 cm. We reviewed our initial experience with laparoscopic partial nephrectomy for solid renal masses without clamping the renal vasculature using a monopolar device that uses radio frequency energy with low volume saline irrigation for simultaneous blunt dissection, hemostatic sealing and coagulation of the renal parenchyma (TissueLink, TissueLink Medical, Inc., Dover, New Hampshire). MATERIALS AND METHODS: From September 2002 to April 2003, 10 patients underwent transperitoneal laparoscopic partial nephrectomy, including 9 with solid renal masses and 1 with a complex cyst. In all cases the renal hilum was dissected and the renal vessels were isolated but none had renal vascular clamping. The TissueLink DS dissecting sealer or Floating Ball (TissueLink Medical, Inc.) was used to dissect the tumor free bluntly, while simultaneously sealing and coagulating bleeders. RESULTS: Mean patient age was 54.6 years (range 42 to 72). Mean American Society of Anesthesiologists score was 2.3 (range 2 to 4). Mean tumor size was 3.9 cm (range 2.1 to 8). The mass had a peripheral location in 7 cases and a central location in 3. Mean operative time was 232 minutes (range 144 to 280) and mean blood loss was 352 ml (range 20 to 1000). One patient received blood transfusion and all tumor margins were negative. Mean hospital stay was 1.7 days (range 1 to 5) and pain medication use was minimal. One patient had a brief period of urine leakage from the lower pole calix, which was managed successfully by ureteral stenting and Foley catheter drainage of the bladder. CONCLUSIONS: Laparoscopic partial nephrectomy can be performed without renal vascular clamping. TissueLink technology allows complete tumor resection and provides adequate parenchymal hemostasis of the tumor bed. Its scant tissue charring production does not interfere with the pathological assessment of the tumor margin status.

Adult↗

PubMed2004

2003 American Urological Association Gallup survey: physician practice patterns, cryosurgery/brachytherapy, male infertility, female urology and insurance/professional liability.

PURPOSE: The Health Policy Survey and Research Committee of the American Urological Association and the Gallup Organization have performed 10 surveys of American urologists since 1992 for the purpose of assessing demographics and practice patterns. The results of the 2003 survey are presented. MATERIALS AND METHODS: A random sample of 510 urologists who have completed urological residencies was interviewed by telephone in February 2003. Major content areas were physician practice patterns, cryosurgery/brachytherapy, male infertility, female urology and insurance/ professional liability. RESULTS: Urologists are older, staying in practice longer and planning to retire later than ever before. Urologists are also seeing more patients in the office every year. Most urologists treat male infertility and female voiding dysfunction. CONCLUSIONS: American urologists are older, working harder and planning on continuing to do so for longer than in any year sampled in the last decade.

Adult↗

PubMed2003

Improved detection of renal pathologic features on multiphasic helical CT compared with IVU in patients presenting with microscopic hematuria.

OBJECTIVES: To examine the virtues of multiphasic helical computed tomography (CT) in the diagnosis of upper urinary tract lesions refractory to identification by intravenous urography (IVU). METHODS: A total of 86 patients (59 men and 27 women), 27 to 88 years old, with microscopic hematuria and negative IVU findings were examined with multiphasic helical CT consisting of a pre-enhancement, late arterial-early cortical-medullary, nephrographic, and excretory phase helical CT of the kidneys, using 3 to 5-mm collimation and 7.5-mm/s table feed. RESULTS: The multiphasic helical CT was conclusive in 84 lesions. Twenty-five cases of early papillary and medullary necrosis, 7 of 8 inflammatory lesions, 3 caliceal diverticula, 1 lupus nephritis, 26 small calculi, 2 medullary sponge kidney, 5 vascular anomalies, and 3 infarcts presented with characteristic manifestations on CT but lacked findings on IVU. Similarly 8 of 9 small malignant neoplasms, 2 small benign neoplasms, and 2 small cysts produced no detectable findings on IVU but were readily diagnosed on helical CT. CONCLUSIONS: Characteristic findings, particularly on late arterial, early corticomedullary, parenchymal, and excretory phase helical CT make possible the diagnosis of early inflammatory disease, small masses and neoplastic lesions, and vascular abnormalities. Limited resolution (needed to identify small calculi) and the lack of ability to capture phases significantly reduce the diagnostic ability of IVU.

Adult↗

PubMed2003

In vivo proteomic analysis of cytokine expression in laser capture-microdissected urothelial cells of obstructed ureteropelvic junction procured by laparoscopic dismembered pyeloplasty.

BACKGROUND AND PURPOSE: Ureteropelvic junction obstruction (UPJO) is defined as an impediment to urinary flow from the renal pelvis into the ureter. The exact cause remains an enigma despite investigations along embryologic, anatomic, and histologic lines. Our goal was to investigate in vivo the expression profile of cytokines in hyperplastic urothelial cells as a means of determining the source of UPJO. MATERIALS AND METHODS: Cellular proteomes of matched normal and hyperplastic urothelial cells were analyzed by laser capture microdissection (LCM) and tissue microdissection and human cytokine proteomic chips. All specimens (N = 9) were surgically obtained from patients undergoing laparoscopic dismembered pyeloplasty and were immediately embedded in O.C.T. solution and flash-frozen in liquid nitrogen. Tissue sections (6 microm) were mounted on uncoated glass slides using a cryostat, fixed in 70% ethanol, stained with hematoxylin and eosin, and sequentially dehydrated in ethanol and xylene. Typically, paired samples of normal and hyperplastic urothelial cells were procured on separate caps from serial sections of each specimen by the Arcturus PixCell II LCM system using 3000 laser pulses and a spot diameter of 30 microm. Total proteins were harvested and quantitated. Differential expression profile analysis of 43 cytokines in normal and hyperplastic cells were performed using human protein chips. Briefly, the membranes were initially probed with protein (150 ng) from normal or hyperplastic cells and sequentially reacted with a cocktail of biotinylated cytokine antibodies and horseradish peroxidase-conjugated streptavidin. The membranes were developed using enhanced chemiluminescence and analyzed by densitometry. RESULTS: Comparative densitometric analysis revealed twofold to fourfold upregulation of growth-related oncogene alpha (GRO-alpha), interleukin (IL)-1alpha, interferon (INF)-gamma, IL-8, tumor necrosis factor (TNF)-alpha, RANTES, and macrophage inflammatory protein-1beta (MIP-1beta) and twofold to fourfold downregulation of transforming growth factor (TGF)-beta and IL-10 in hyperplastic urothelial cells compared with paired control cells. CONCLUSIONS: We here report the efficient application of LCM and proteomic array chips for expression profile analysis of cytokines in vivo. Because the etiology and pathogenesis of UPJO are still fragmentary, the marked heterogeneity of the observed cytokine alterations reported here may be of significance. Further studies are required to elucidate the functional significance of the differentially expressed cytokines in the pathogenesis of the disease.

Adult↗

PubMed2002

CT-guided biopsy of indeterminate renal cystic masses (Bosniak 3 and 2F): accuracy and impact on clinical management.

The purpose of this study was to determine ability of cyst aspiration and core biopsy to differentiate malignancies, and benign lesions needing intervention from benign complex cysts in the group of Bosniak 2F and 3 renal cysts. One hundred ninety-nine indeterminate complex renal cysts were biopsied under CT or US guidance using a coaxial system (19-G sheath, 20- or 21-G Chiba or Franseen or 18-G spring biopsy needle). Cytology, amylase, lipase, LDH, fat, protein, urea nitrogen, creatine, and culture and sensitivity were assessed in all patients, histopathology in 116, and flow cytometry in 32. In 179 patients (87.9%) a definitive diagnosis was made; in 20 the specimen was inadequate. Twenty of 28 malignancies were correctly diagnosed (sensitivity 0.71); 27 of 31 benign lesions needing intervention (sensitivity 0.87) and 128 of 140 benign complex cysts (sensitivity 0.91). All inconclusive biopsies were explored revealing six malignancies. There were four CT biopsy misdiagnoses: two renal cell carcinomas; one angiomyolipoma; and one abscess. Guided cyst puncture aspiration and core biopsy significantly altered management of Bosniak 3 and 2F renal cysts obviating surgery or invasive procedures in 70% of the patients with an affirmed diagnosis of benign complex cyst and rendering timely surgical and other interventions in the remaining patients. Long-term follow-up (mean 5.6 years) revealed no further misdiagnosis.

Adult↗

PubMed2002

Computerized tomography tailored for the assessment of microscopic hematuria.

PURPOSE: We report the results of a multicenter study of arterial, corticomedullary, nephrographic and excretory phase helical computerized tomography (CT) for detecting and characterizing abnormalities causing asymptomatic microscopic hematuria. MATERIALS AND METHODS: We evaluated 350 consecutive patients, including 216 men and 134 women 23 to 88 years old, with asymptomatic microscopic hematuria of undetermined cause at 4 medical centers. Patients with known urological pathology were excluded from study. We performed 4 helical CT sequences, including pre-enhancement phase imaging from kidney to symphysis pubis, arterial phase imaging of the kidney and lower pelvis, corticomedullary nephrographic phase imaging of the kidney and lower pelvis, and excretory phase imaging from kidney to symphysis pubis with 2 to 5 mm. collimation and 1 to 1.5 pitch. RESULTS: Of 171 proved lesions 158 were correctly diagnosed. There were 10 false-positive and 13 false-negative diagnoses, indicating 0.9239 sensitivity, 0.9441 specificity, 0.9404 positive and 0.9285 negative predictive values, (p <0.001). All cases of congenital renal lesions, calculous disease, ureteral lesion and neoplastic lesion of the bladder were correctly diagnosed, as were 40 of 41 inflammatory renal, 21 of 23 renal masses and 13 of 16 inflammatory bladder lesions. In 27 patients with renal calculi the study was limited to pre-enhancement spiral CT. CONCLUSIONS: A positive diagnosis rate of 45.1% (158 of 350 cases) for the causes of heretofore refractory cases of hematuria with high sensitivity and specificity attest to the effectiveness of our hematuria CT protocol and support its use.

Adult↗

PubMed2002

2001 American Urological Association Gallup Survey: changes in physician practice patterns, satisfaction with urology, and treatment of prostate cancer and erectile dysfunction.

PURPOSE: The Health Policy Survey and Research Committee of the American Urological Association and the Gallup organization have performed 9 surveys of American urologists since 1992 for the purpose of assessing demographics and practice patterns. The results of the 2001 survey are presented. MATERIALS AND METHODS: A random sample of 507 urologists was interviewed in February and March 2001. Major content areas were physician practice patterns, cryosurgery/brachytherapy, prostate specific antigen, erectile dysfunction, Medicare and the Internet. RESULTS: Membership in the American Urological Association continues to increase among American urologists. The number of patients seen weekly in the office also continues to increase. While age at retirement has not changed significantly, most urologists are satisfied with the specialty and increasing numbers are using the Internet. CONCLUSIONS: Minimally invasive procedures such as brachytherapy for prostate cancer continue to proliferate and there is evidence that the specialty of urology is continuing to become more office based. The demand for urological services appears to be continuing to increase.

Adult↗

PubMed2002

Urology practice patterns after residency training in radical perineal prostatectomy.

OBJECTIVES: To assess the impact of residency training in radical perineal prostatectomy (RPP) on subsequent use of RPP in urology practice. METHODS: Urologists who completed residency training at Tulane University and the University of California, San Diego, Medical Center from 1977 to 1999 were surveyed by anonymous questionnaire for their practice demographics, operative experience in RPP during residency, the role of RPP in their current practice, and the reasons they do or do not perform RPP. RESULTS: Of 91 former residents, 61 (67%) responded. RPP was in current use by 41% of the urologists trained in RPP during residency and by 13% of those with no residency RPP training. Those who had performed 10 or more RPPs during residency reported a higher rate of current RPP use (53%) than did those who had performed fewer than 10 RPPs during residency (21%). Urologists trained in RPP during residency cited partner preference (28%) and inadequate exposure (26%) as reasons they did not perform RPP; respondents with no residency RPP training cited inadequate exposure (25%), difficulty of the operation (25%), and time required to perform the operation (25%). CONCLUSIONS: A urologist with residency training in RPP is more likely to perform RPP in practice than is a urologist without such training. The intensity of training, in the form of greater operative experience during residency, had a positive impact on the future use of this specialized surgical technique.

Group Practice↗

PubMed2002

Potential role for the nuclear transcription factor NF-kappa B in the pathogenesis of ureteropelvic junction obstruction.

BACKGROUND AND PURPOSE: In an effort to better understand the pathophysiology of ureteropelvic junction (UPJ) obstruction and to determine possible predisposing factors for endopyelotomy failures, we compared the activation of the nuclear factor NF-kappa B and proinflammatory cytokines in patients who failed endopyelotomy and post-primary pyeloplasty patients. We hypothesized that an imbalance toward proinflammatory cytokines may promote fibrosis prior to and after endopyelotomy in patients with severe hydronephrosis. PATIENTS AND METHODS: The charts of patients who underwent open pyeloplasty at our institution were reviewed. Group I was the control group, consisting of 10 patients who had undergone radical nephrectomy for renal-cell carcinoma without involvement of the renal pelvis. Group II was the endopyelotomy failure group and included 11 patients over the age of 15 years treated for symptomatic UPJ obstruction. Group III included six patients who underwent primary pyeloplasty. Paraffin-embedded blocks of UPJ segments from each of these patients were obtained, and immunohistochemical detection of NF-kappa B activation, interleukin (IL)-6, and hypoxia-inducing factor (HIF) was performed. As an in-vitro model, activation of NF-kappa B and cytokine gene expression were also monitored in human bladder T24 urothelial cells 24 hours after exposure to hypoxia (1% O(2)) in the presence and absence of NF-kappa B inhibitor. The activation of NF-kappa B was determined by immunocytochemical analysis, whereas cytokine gene expression was measured using reverse transcriptase-polymerase chain reaction. RESULTS: Immunoreactivity to NF-kappa B was observed in the nuclei of the urothelium and muscle layer in all patients in group II. Such immunostaining suggests increased nuclear translocation and activation of this transcription factor. Those patients with increased expression of NF-kappa B demonstrated increases in IL-6 expression as well. Hypoxia-inducing factor was identified in all the tissue samples tested in group II. Stimulation of the human urothelial cells by hypoxia, known to activate NF-kappa B, resulted in an increase in the levels of IL-1 and IL-6 transcripts compared with hypoxia-exposed cells in the presence of NF-kappa B inhibitors. CONCLUSIONS: The NF-kappa B factor was upregulated and proinflammatory cytokines were activated in patients with UPJ obstruction who failed endopyelotomy. Proinflammatory cytokines upregulated by this nuclear factor can result in fibrosis and affect healing after endopyelotomy. Hypoxia appears to activate this nuclear factor. Further studies correlating the degree of hydronephrosis with the activation of HIF are necessary to clarify the role of severe hydronephrosis and its management in UPJ obstruction.

Adolescent↗

PubMed2002

Urology practice patterns after residency training in laparoscopy.

PURPOSE: Laparoscopic training has been incorporated into many urology residency programs. Although the impact of laparoscopic training courses has been examined, the impact of residency training in laparoscopy on subsequent urology practice patterns has not been assessed. MATERIALS AND METHODS: Urologists completing their residency from 1977 through 1999 at Tulane University and the University of California-San Diego were sent anonymous questionnaires in September 2000. The questionnaires evaluated practice demographics, operative experience in laparoscopy during residency, and the role of laparoscopy in the urologist's current practice. Factors impacting the decision to perform or not perform laparoscopy were evaluated. RESULTS: Sixty-one former residents (67%) responded to the questionnaire. Urologists were more likely to perform laparoscopic procedures if they had been trained during their residency (69%) than if they had no experience during residency (34%; p < 0.025). Intensity of laparoscopic experience in residency did not appear to correlate with ongoing practice, with 73% of residents having <15 cases during residency training continuing to perform laparoscopy compared with 67% of residents doing 15 to 80 laparoscopic cases. Urologists who had been trained in laparoscopy during residency cited the need for more training (47%) and inadequate case volume (47%) as reasons for not currently performing laparoscopy. Among those who had received residency training, the most common reasons given were inadequate case volume (61%) and increased operative time (57%). CONCLUSIONS: This survey suggests that laparoscopic procedures are more likely to be performed by physicians who have received training during residency. As the number of urologists who have been trained in laparoscopy during residency increases, shifts in practice patterns will continue to evolve, along with advances in urologic laparoscopy.

Humans↗