Biomedical subjects
Publications and source records attributed to Maxwell V Meng.
We review a laparoscopic, intracorporeal technique of securing the square knot. It is useful when a surgeon's knot is insufficient to maintain tissue approximation. Advantages include the use of standard tying methods, lack of extracorporeal knot creation or need for a pushing device, and ability to secure the knot in difficult locations.
Although once reserved for the management of metastatic prostate cancer, androgen deprivation therapy (ADT) is being used increasingly to treat lower stages of disease. We sought to assess patterns of ADT use in a contemporary cohort of men newly diagnosed with prostate cancer. Men with newly diagnosed prostate cancer who had > or =12 months of follow-up evaluation were identified in a national disease registry of patients with prostate cancer. The patterns of ADT use, both primary and secondary, were characterized and stratified by risk according to prostate-specific antigen levels, clinical stage, and Gleason score. In a cohort of 1485 men, 46% underwent ADT at some point during their treatment: 41% as primary therapy (either sole therapy or neoadjuvant therapy), and 5% as secondary therapy. In all, 50% of men receiving initial ADT had low- or intermediate-risk disease characteristics. Among patients treated with radical prostatectomy and radiation therapy, neoadjuvant ADT was administered in 20% and 48% of patients, respectively. Secondary hormonal manipulation was observed in 5% and 7% of patients treated initially with surgery or radiation, respectively. ADT is commonly used to treat men with prostate cancer. Much of the use of ADT is in men with low- and intermediate-risk disease characteristics. The appropriateness of such therapy requires further study, including its effect, not only on disease endpoints, but also on resource utilization and health-related quality of life.
INTRODUCTION: Laparoscopic enterocystoplasty provides a minimally invasive approach to bladder augmentation in the patient with a neurogenic bladder. In previously published reports, portions of the procedure were performed extracorporeally. We report our technique of complete intracorporeal laparoscopic enterocystoplasty. TECHNICAL CONSIDERATIONS: Important elements of the operation include (a) preoperative evaluation of patient compliance and videourodynamic studies; (b) cystoscopic placement of externalized ureteral stents; (c) transperitoneal placement of five radially dilating trocars; (d) identification of the cecum; (e) proximal mobilization of ileum sufficient for pelvic placement; (f) measurement of ileal length with segment of precut vessel loop; (g) vertical cystotomy after incising peritoneum and entering the space of Retzius; (h) ileal division and side-to-side anastomosis using endoscopic gastrointestinal anastomosis staplers; (i) detubularization and freehand intracorporeal suturing into a U-shaped configuration; (j) fixing ileal patch at the 6 and 11-o'clock positions; (k) completion of ileal-bladder anastomosis in quadrants with running sutures; (l) irrigation of bladder and placement of a closed suction drain in the pelvis; and (m) cystogram 4 weeks postoperatively. CONCLUSIONS: Pure laparoscopic enterocystoplasty is an advanced procedure that is technically feasible and yields excellent results, but has unproven benefits. We perform the entire operation intracorporeally with traditional instruments and do not rely on suturing devices or extracorporeal knots. Additional experience and technological developments may result in routine laparoscopic urinary augmentation and continent diversion.
We report a case of a mucus-filled kidney (muconephrosis) encountered during laparoscopic nephrectomy for presumed xanthogranulomatous pyelonephritis. Conversion to open nephrectomy and en-bloc right hemicolectomy were necessary because of severe perinephric fibrosis and suspected renal-enteral fistula. Pathologic examination revealed a renal pelvic villous adenoma and diffuse intestinal metaplasia of the urothelium; no enteral communication or gastrointestinal pathologic features were found. Urothelial villous adenoma is extremely rare, and one should consider neoplastic etiologies, including appendiceal mucinous cystadenocarcinoma and mucus-secreting adenocarcinoma of the renal pelvis, in directing the appropriate management of muconephrosis.
OBJECTIVES: To describe our experience with precaval right renal arteries and discuss a theory of development of this unusual vascular variant. The right renal artery typically passes dorsal to the inferior vena cava and is thought to represent a consistent anatomic relationship. METHODS: Three cases of precaval renal arteries were identified during laparoscopic and endourologic procedures. The intraoperative and radiologic anatomic findings were recorded. The embryologic origins of the kidney and renal artery were reviewed to postulate a mechanism for the precaval location of a renal artery. RESULTS: In all cases, the precaval renal artery was an accessory vessel to the lower pole. Computed tomography demonstrated the location of the accessory artery ventral to the vena cava; the superior "main" renal artery was dorsal to the vena cava. In addition, bifid collecting systems (ie, pelves) were present, and the renal contours suggested nearly complete fusion of two renal moieties, with normal location and rotation of the kidney. No other cases of precaval renal arteries were recorded in urologic operative reports during the past 5 years at the University of California, San Francisco. CONCLUSIONS: The precaval renal artery is a rare but important variant of renal vascular anatomy. Several associated findings on computed tomography (bifid collecting system, enlarged kidney) may suggest its presence. The embryologic origin is likely due to the late, incomplete division of the ureteral bud during the eighth week of gestation. The renal artery to the lower pole develops and persists after the posterior cardinal vein has become the inferior vena cava but before gonadal descent.
OBJECTIVES: To characterize the frequency and nature of problems with linear cutting staplers to help prevent complications in the future. These devices are often used during laparoscopic urologic procedures. METHODS: We retrospectively reviewed the experience with laparoscopic linear cutting staplers at two institutions routinely performing urologic laparoscopy and analyzed the difficulties with any staplers. Data from the Food and Drug Administration Center for Devices and Radiological Health were also examined to determine the prevalence and types of reported problems. RESULTS: In performing approximately 460 laparoscopic cases, we encountered 5 problems (1%) with endovascular gastrointestinal anastomosis staplers. Fifty-five additional cases in 50 patients were documented in the Food and Drug Administration database. Of the 55 patients, 15 (27%) required open conversion to manage the problem, 8 (15%) received blood transfusions, and 2 (4%) died postoperatively. Twenty-two events occurred during 19 laparoscopic donor nephrectomies (35%) without associated graft dysfunction, damage, or loss. All phases of instrument use were subject to problems; however, abnormal firing of the stapler and improper staple formation were the most common and morbid aspects of device malfunction. CONCLUSIONS: Despite the general reliability of linear cutting staplers, difficulties were encountered in every step of use. Most situations were successfully managed by prompt identification and appropriate intracorporeal maneuvers. Nevertheless, significant morbidity may occur, and conversion to an open operation should be considered. Many potential problems can be avoided by surgeon and staff education, and one should be aware of the alternative methods of tissue ligation currently available.
Prostate cancer is the most common non-cutaneous malignancy in men and poses a substantial risk to the life and health of patients. Treatment options for patients with prostate cancer are plentiful. Radical prostatectomy is one option that can be performed using several different surgical approaches. It can be performed with limited risk of complications and is likely to be curative in patients with organ-confined disease and those with limited extracapsular extension.
Although definitive therapy with either radical prostatectomy or radiation therapy can be effective, the optimal treatment for prostatic adenocarcinoma remains controversial. Patients may be at significant risk for primary treatment failure even with apparent clinically localized disease. Thus, there has been increased interest in initial multimodal therapy in order to maximize the potential for cure. Neoadjuvant hormonal therapy prior to radical prostatectomy has been used for several decades and a large body of literature discusses its use; nevertheless, the current data suggest that it only decreases rates of positive surgical margins without improving prostate-specific antigen (PSA)-free or disease-free survival. Novel neoadjuvant hormonal and chemotherapeutic regimens are under investigation and may improve outcomes for patients undergoing radical prostatectomy.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The early diagnosis of prostate cancer has been facilitated by the development of serum prostate-specific antigen (PSA) testing and evolution in transrectal ultrasound-guided biopsy of the prostate. Over a decade has passed since the initial recommendations for systematic sextant sampling of the prostate to increase the accuracy of cancer detection. Subsequently, variations in the number and location of biopsies have been proposed to maximize prostate cancer detection and obtain more complete information regarding tumor grade, tumor volume, and local stage. Although current biopsy strategies provide a wide sampling of the prostate gland, biopsy histology may not be conclusive for either the presence or absence of adenocarcinoma. High-grade prostatic intraepithelial neoplasia (HGPIN) is found in a significant fraction of patients undergoing transrectal prostate biopsies. In this article, we discuss the significance of high-grade prostatic intraepithelial neoplasia and other abnormal histology findings and current evidence addressing the presence of cancer and need for additional prostate biopsies.
We sought to determine the utility of adding apical anterior horn biopsies to systematic prostate sampling regimens in detecting cancer in men with measured prostate volume < or =50 cc. We reviewed the biopsy data of consecutive men referred for an abnormal digital rectal exam or PSA elevation > or =4.0 ng/mL. All of these patients underwent lesion directed biopsy as well as a systematic 12-core biopsy regimen consisting of the standard sextant, bilateral lateral mid- and lateral base-sites, and bilateral apical anterior horn sites. Overall cancer detection and unique cancer detection rates were calculated for each of the 12 sites, stratified by race, age, PSA, and findings on digital rectal exam. In addition, cancer detection rates of various biopsy schemes were calculated and compared. There were 255 men undergoing biopsy who had calculated prostate volume < or =50 cc, and the prostate cancer detection rate was 47%. The overall cancer detection rate of apical anterior horn biopsies ranged between 29% and 56%. The utility of these biopsies was greatest in men with normal rectal exam and PSA <10 ng/mL, with unique cancer detection rates of 6% and 4%, respectively. Including the apical anterior horn biopsies in an 8-biopsy scheme (anterior, apex, lateral mid, lateral base) yielded cancer detection rates greater than 91% in all subgroups that were not statistically different from extended 10- and 12-core biopsy regimens. Apical anterior horn prostate biopsies target cancers that are potentially in the anterior region of the prostate, a region under-sampled using traditional schemes. The use of these biopsies as part of an 8-core biopsy pattern provides high cancer detection in all groups of patients and may represent a new standard.
The computed tomography and magnetic resonance imaging findings in 2 cases of inferior vena caval thrombus associated with metastases to the kidney are presented. In both cases, the radiologic findings were suggestive of renal cell carcinoma. Recognition that metastases to the kidney can be associated with inferior vena caval thrombus broadens the differential diagnosis in a patient with a renal mass, an inferior vena caval filling defect, and a known primary malignancy, potentially altering the diagnostic approach.
BACKGROUND: Adult perineal soft tissue sarcomas are rare. Fewer than 30 cases have been reported, and all were diagnosed after surgical resection by histologic examination. Below we report a case in which the diagnosis was established preoperatively by fine needle aspiration (FNA). CASE: A 27-year-old man presented with a firm, midline, perineal mass. Magnetic resonance imaging showed a 3-cm, enhancing mass that was considered neoplastic. FNA biopsy, followed by cytologic examination, revealed moderately cellular aspirates composed of discohesive, small, blue cells with scant cytoplasm, high nuclear/cytoplasmic ratios and pleomorphic nuclei with irregular nuclear contours; uniform, hyperchromatic chromatin; and occasional mitotic figures. Frequent naked nuclei and scattered cells with more abundant, dense cytoplasm and eccentric nuclei were also noted. The diagnosis of rhabdomyosarcoma was favored on FNA and was corroborated by immunohistochemical stains for desmin, myogenin and CD56. Upon surgical resection, the diagnosis of alveolar rhabdomyosarcoma was confirmed histologically and immunophenotypically. CONCLUSION: FNA is a useful tool in diagnosing soft tissue lessions of the perineum, including rare primary tumors, such as adult rhabdomyosarcoma. In this case, early identification avoided incisional biopsy and directed appropriate extirpative surgery and reconstruction considerations.
INTRODUCTION: Compare the outcomes between kidney morcellation and two types of open specimen extraction incisions, several covariates need to be taken into consideration that have not yet been studied. MATERIALS AND METHODS: We retrospectively reviewed 153 consecutive patients who underwent laparoscopic nephrectomy at our institution, 107 who underwent specimen morcellation and 46 with intact specimen removal, either those with connected port sites with a muscle-cutting incision and those with a remote, muscle-splitting incision. Operative time, postoperative analgesia requirements, and incisional complications were evaluated using univariate and multivariate analysis, comparing variables such as patient age, gender, body mass index (BMI), laterality, benign versus cancerous renal conditions, estimated blood loss, specimen weight, overall complications, and length of stay. RESULTS: There was no significant difference for operative time between the 2 treatment groups (p = 0.65). Incision related complications occurred in 2 patients (4.4%) from the intact specimen group but none in the morcellation group (p = 0.03). Overall narcotic requirement was lower in patients with morcellated (41 mg) compared to intact specimen retrieval (66 mg) on univariate (p = 0.03) and multivariate analysis (p = 0.049). Upon further stratification, however, there was no significant difference in mean narcotic requirement between the morcellation and muscle-splitting incision subgroup (p = 0.14). CONCLUSION: Morcellation does not extend operative time, and is associated with significantly less postoperative pain compared to intact specimen retrieval overall, although this is not statistically significant if a remote, muscle-splitting incision is made. Morcellation markedly reduces the risk of incisional-related complications.