Dual-tracer PET/CT in renal angiomyolipoma and subtypes of renal cell carcinoma.

UNLABELLED: We studied the metabolic characteristics of RCC subtypes and angiomyolipoma with 18F-FDG and 11C-acetate PET/CT. METHODS: Fifty-eight patients with both baseline CT and dual-tracer PET/CT were recruited: 10 angiomyolipoma (16 lesions) and 48 RCC (50 lesions). Each lesion was assessed for SUVmax ratio (lesion-to-normal kidney) on 11C-acetate/18F-FDG PET and attenuation density on CT. Receiver operating characteristic (ROC) curve was analyzed to define the threshold of 11C-acetate SUVmax ratio for differentiating angiomyolipoma from RCC. Thirty-nine RCC patients were selected for 3-year disease-free survival analysis. RESULTS: All angiomyolipoma showed negative 18F-FDG but markedly increased 11C-acetate metabolism, significantly higher than RCC (11C-acetate SUVmax ratio = 4.11 ± 0.53 vs 2.00 ± 0.71; P < 0.05). 11C-acetate SUVmax ratio = 3.71 could differentiate angiomyolipoma including "fat-poor angiomyolipoma" (n = 10) from RCC with sensitivity of 93.8% (15/16) and specificity of 98.0% (49/50). Different RCC subtypes/grades (25 low- and 11 high-grade clear cell [CC], 7 chromophobe, 4 papillary, and 1 collecting duct) were found to have different dual-tracer metabolic pattern (P < 0.05), with overall RCC detection sensitivity of 90% (45/50). All chromophobe RCC were avid only for C-acetate but not 18F-FDG, whereas papillary RCC were primarily the opposite. RCC-CC showed variable dual-tracer uptake: high-grade more avid for F-FDG, low-grade more for 11C-acetate. Four RCC cases negative by dual-tracers were of low-grade RCC-CC. "Primary RCC being 18F-FDG-avid" was the only independent predictor of RCC recurrence in 3 years (P < 0.05), with a median disease-free survival of 22 months. CONCLUSION: 11C-acetate PET/CT helps in differentiating "fat-poor angiomyolipoma" from RCC. Dual-tracer PET/CT has value in diagnosis of RCC subtypes and predicting survival.

Modular surgical training for endoscopic extraperitoneal radical prostatectomy.

OBJECTIVE: To develop a modular training scheme which enabled the use of individual steps of laparoscopic radical prostatectomy (RP) for teaching and training surgeons with varied experience, including residents with no experience in open RP, as in extending laparoscopic surgery to more complex operations like RP, the proper training of urologists is crucial. SUBJECTS AND METHODS: The technique of endoscopic extraperitoneal RP (EERP) was divided into 12 individual steps of differing complexity. The levels of difficulty were called "modules" and graded according to their requisite skills from module 1 (lowest level of difficulty) to module 5 (highest level). Based on this modular system we established a training programme whereby the trainee learns the procedure in a mentor-initiated schedule. During each training operation the trainee only performs the modules (steps) of the operation, which correspond with his or her actual skill level. The mentor performs all the other steps, with the trainee assisting. Four trainees with different surgical experience participated in the study. RESULTS: After a phase of assisting and camera holding during EERP, the trainees entered the modular training programme and required 32-43 procedures until they were considered to be competent. An analysis of the first 25-50 procedures done independently by the trainee showed mean operative times of 176-193 min and a transfusion rate of 1.3%. Complications during and after EERP requiring re-intervention were one each of recto-urethral fistula, haemorrhage, symptomatic lymphocele and anastomotic leak. The positive margin rate for pT2 disease was 12.2% and for pT3 tumours 37%. CONCLUSION: The modular concept for teaching EERP is an attractive concept, which overcomes many of the problems involved in complex laparoscopic procedures. Based on a highly standardized technique, this concept offers a short learning curve; it enables training on different sites in cooperation with a high-volume centre, and it makes it possible to start with this complex procedure as a beginner or with no experience in open RP.

Endoscopic extraperitoneal radical prostatectomy in patients with prostate cancer and previous laparoscopic inguinal mesh placement for hernia repair.

INTRODUCTION: Since laparoscopic inguinal hernia repair has become a frequently performed surgical procedure, it is inevitable that patients who have been candidates for laparoscopic radical prostatectomy (LRP) may have had such prior intervention. The inguinal hernia repair might take the form of either total extraperitoneal hernioplasty (TEP) or transabdominal extraperitoneal hernioplasty (TAPP), with mesh placement. The objective was to show that performing endoscopic extraperitoneal radical prostatectomy (EERPE) in such patients was safe and feasible, and also to suggest modifications of the technique to facilitate the surgery. PATIENTS AND METHODS: There were no specific selection criteria and patients with prior mesh placements were encountered during the management of all consecutive patients undergoing EERPE. Modifications in the port placements were made to accommodate for previous mesh placements on the right and left side. The area of prior mesh placement was excluded from the dissection when creating the extraperitoneal space. The operation was performed, thereafter, using the standard EERPE method. RESULTS: Out of a total of 750 patients operated on with EERPE, 14 had prior TEP or TAPP with mesh placement. In both groups there were no differences found in the mean operative time. There were no major complications or reinterventions in patients with prior mesh placement. In each group (i.e. TEP and TAPP), a small bladder injury was diagnosed and managed intraoperatively with no further complication. One vascular injury to the inferior epigastric vessels was managed intraoperatively without significant blood loss. None of the 14 patients required blood transfusion. The mean catheterization time was 6.9 days. CONCLUSION: Although certain problems were presented by previous TEP/TAPP, it is nevertheless feasible to perform EERPE. By adapting port placements and surgical techniques the operation can be performed safely and with a good operative outcome.

Endoscopic extraperitoneal radical prostatectomy: oncological and functional results after 700 procedures.

PURPOSE: We review our experience with endoscopic (totally) extraperitoneal radical prostatectomy (EERPE) as first line therapy for localized prostate cancer. MATERIALS AND METHODS: A total of 700 consecutive patients underwent EERPE. Mean patient age was 63.4 years (range 42 to 77). Mean preoperative prostate specific antigen was 10.7 ng/ml (range 1.4 to 82). A total of 206 patients (29.4%) had a history of previous lower abdominal or pelvic surgery including inguinal hernioplasty with mesh placement and 43 patients (6.1%) had a history of prostatic intervention (transurethral resection of the prostate, high intensity focused ultrasound, Millin prostatectomy, radiotherapy). After preparation of the preperitoneal space the technique of EERPE duplicates the steps of classic open descending retropubic radical prostatectomy including a nerve sparing EERPE when indicated. RESULTS: Mean operative time was 151 minutes (range 50 to 320). There was no conversion and the transfusion rate was 0.9% in 6. Four patients (0.6%) had intraoperative rectal injuries which were treated endoscopically with a 2-layer suture. A total of 14 patients (2%) required early and 3 patients (0.4%) required late postoperative reintervention. Pathological stage was pT2a in 89 patients (12.7%), pT2b in 54 (7.7%), pT2c in 245 (35%), pT3a in 229 (32.7%), pT3b in 79 (11.2%) and pT4 in 4 patients (0.6%). Positive surgical margins were found in 10.8% (42 of 388) of patients with a pT2 tumor and in 31.2% (96 of 308) of patients with a pT3 tumor. Pelvic lymph node dissection was performed in 266 patients (38%), of whom 14 (5.3%) were found to have lymph node involvement. Mean catheterization time was 6.2 days. Six months after surgery 83.8% of the patients were completely continent, 10.4% needed 1 to 2 pads daily and 5.8% of patients needed more than 2 pads daily. Of all patients who underwent nerve sparing procedures, 100 patients had a postoperative followup of 6 months. Of the 66 patients with the unilateral nerve sparing approach 8 (12.1%) had erections sufficient for intercourse and 16 of 34 patients (47.1%) with the bilateral nerve sparing procedure had erections sufficient for intercourse with or without the help of phosphodiesterase type 5 inhibitors. CONCLUSIONS: The results of this series are promising. Perioperative morbidity is low, and short-term oncological and functional results are favorable. Although the followup is too short to draw definite conclusions, it is obvious that a nerve sparing approach in EERPE is feasible and reproducible. Our data demonstrate that EERPE can be performed with equal efficacy and results compared with laparoscopic transperitoneal radical prostatectomy, while providing the ease and safety of a totally extraperitoneal approach, completely avoiding intraperitoneal complications.

Altered expression of aquaporin-2 in human explants with chronic renal allograft dysfunction.

OBJECTIVE: To investigate the distribution of aquaporins, a recently discovered family of transmembrane water channels, in human renal explants, with specific reference to chronic renal allograft dysfunction (CRAD). MATERIALS AND METHODS: Immunohistochemistry for aquaporin-1 and -2 was used in 11 explants, of which five had clinically and histologically confirmed CRAD. Controls were taken from the six explants unaffected by CRAD and from histologically normal areas of six kidneys excised for renal tumours. RESULTS: In the renal tumour control group, aquaporin-1 immunoreactivity was detected in the glomerular endothelium, Bowman's capsule, the proximal convoluted tubules and the thin limb of the loop of Henle, whereas immunoreactivity for aquaporin-2 was detected in the collecting ducts only. Of the explants without CRAD, where architecture was preserved, immunoreactivity for aquaporin-1 and -2 was the same as in the renal tumour controls. In the two explants with no CRAD and loss of collecting ducts, there was no aquaporin-2 immunoreactivity. In five explants with CRAD, immunoreactivity for aquaporin-2 was decreased or absent from the medulla to the cortex. The apparent decreased immunoreactivity of aquaporin-1 in this group was secondary to a decrease in the number of viable proximal tubules. CONCLUSION: There was less aquaporin-2 immunoreactivity in human renal explants diagnosed with CRAD, starting from the medullary region. In explants with no CRAD and viable collecting ducts, or in normal controls, aquaporin-2 immunoreactivity remained unchanged. Aquaporins might be useful as markers for CRAD.

Impact of previous surgery on endoscopic extraperitoneal radical prostatectomy.

OBJECTIVES: To assess the impact of previous surgery on endoscopic extraperitoneal radical prostatectomy (EERPE). METHODS: A total of 500 patients who underwent EERPE for clinically localized prostate cancer between December 2001 and April 2004 were stratified into five groups: group 1, no previous abdominal, inguinal, or prostate surgery; group 2, previous upper abdominal surgery; group 3a, previous lower abdominal or pelvic surgery or open inguinal hernioplasty; group 3b, laparoscopic or endoscopic inguinal hernioplasty; group 4, previous prostate surgery; and group 5, a combination of groups 2, 3, and/or 4. Groups 1 and 2 were analyzed together, because the previous operative fields in group 2 were distant from the space of Retzius. The operative times, complications, and reinterventions were analyzed with the Mann-Whitney U test, chi-square test, and Fisher exact test. RESULTS: Of the 500 patients, 335 (67%) and 165 (33%) were in groups 1 and 2 and groups 3 to 5, respectively. The mean overall operative time was 149 +/- 30 minutes. Four patients (0.8%) required transfusions, with no conversion to open surgery and no mortality. A total of 90 complications (18%) and nine reinterventions (1.8%) occurred. EERPE was subjectively more demanding and challenging in patients with previous minimally invasive hernioplasty with mesh placement. No statistical significance was detected between the no=surgery (groups 1 and 2) and previous surgery (groups 3 to 5) patients in terms of overall operative time, positive surgical margin status, complications, or reinterventions. CONCLUSIONS: Endoscopic extraperitoneal radical prostatectomy is feasible in patients with various previous abdominal surgical procedures. Previous surgery did not seem to affect the overall operative time or complication or reintervention rate. Previous minimally invasive hernia repair with mesh placement made EERPE more demanding but was not a contraindication.

Parastomal hernia repair using the lateral approach.

OBJECTIVE: To review the results of repairing a parastomal hernia after ileal conduit formation, using the lateral approach. PATIENTS AND METHODS: We retrospectively assessed 18 patients (9%) who developed a parastomal hernia, from 211 who had an ileal conduit created between 1982 and 2001; 15 had a surgical repair using a lateral incision. RESULTS: All 15 patients resumed a normal diet 1 day after surgery; the median (range) hospital stay was 4 (2-14) days. In two patients with a large hernia and difficult repair the stomas became ischaemic and required refashioning. Only one of these two patients required complete conduit replacement. The median (range) follow-up was 15 (1-72) months. A recurrence of the hernia was recorded in one grossly overweight patient. CONCLUSION: The lateral approach obviates the need for laparotomy and stomal relocation, and enhances a quick return of bowel function and early recovery. However, extra care is needed in managing the very large and difficult hernia, to avoid compromising the ileal conduit. The success and complication rates of the current series are within acceptable limits and this technique can be included in the options for managing parastomal hernia.

Expression of nitric oxide synthase immunoreactivity in the human female intramural striated urethral sphincter.

PURPOSE: While we have recently detected neuronal nitric oxide synthase (nNOS) immunoreactivity in a heterogeneous population of human male urethral striated muscle, to our knowledge the association of nNOS in the female counterpart is unknown. We investigated the association of nNOS with female urethral striated muscle and re-investigated muscle fiber types. MATERIALS AND METHODS: Cryostat sections were taken from the middle third of 4 human female urethras. Nicotinamide adenine dinucleotide phosphate diaphorase histochemistry and nNOS immunohistochemistry were performed. Muscle fiber types were identified by myofibrillar adenosine triphosphatase histochemistry and fast twitch troponin T immunohistochemistry. The association between nNOS immunoreactivity and muscle fiber type was analyzed. RESULTS: Positive staining for nicotinamide adenine dinucleotide phosphate diaphorase histochemistry and nNOS immunoreactivity were recognized in the sarcolemma of 43.9% of female urethral striated muscle fibers. Immunoreactivity for fast twitch troponin T immunohistochemistry was demonstrated by 2% of the striated fibers. The use of myofibrillar adenosine triphosphatase showed that all fibers darkly stained uniformly at a pH of 9.6, 4.6 and 4.3, suggesting that they were myofibrillar intermediate muscle fibers. The results allowed the differentiation of 2 subgroups of fibers, namely smaller fibers (modal diameter 10.1 to 15.0 microm.) without nNOS immunoreactivity and larger fibers (modal diameter 15.1 to 20.0 microm.) with nNOS immunoreactivity. CONCLUSIONS: To our knowledge female urethral striated muscle has for the first time been found to consist of myofibrillar intermediate fibers and nNOS was positively localized in the sarcolemma of a subgroup of the fibers. This study provides a basis for further investigation into female urethral striated sphincter function and changes in pathological conditions.