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Biomedical subjects

Howard N Winfield

Publications and source records attributed to Howard N Winfield.

At least 19 recordsLinked to original sources
PubMed2006

Laparoscopic augmentation cystoplasty: a comparison between native ileum and small intestinal submucosa in the porcine model.

OBJECTIVES: To determine the feasibility of laparoscopic augmentation cystoplasty (LAC) in the porcine model and to compare LAC using standard bowel vs a small intestinal submucosa (SIS) allograft. MATERIALS AND METHODS: Fourteen female pigs underwent LAC; six had standard ileal AC and eight AC with SIS. All the pigs had limited cystometrogram studies before surgery to determine bladder capacity. At 6 weeks after surgery the pigs were anaesthetized, the bladder capacities were re-assessed and then the pigs were killed; the bladders were harvested and examined histologically. RESULTS: In all, 12 of 14 pigs completed the 6-week survival period; two pigs from the SIS group died from urinary ascites secondary to anastomotic leaks at the cystoplasty site. There were no complications in the ileal augmentation group. The operative duration was similar in both groups. The bladder capacities increased significantly in both groups, although more reliably in the native ileum group. In two pigs in the SIS group there was no increase in bladder capacity. CONCLUSIONS: LAC is feasible in the porcine model and results in a significant increase in bladder capacity. AC using SIS does not appear to increase bladder capacity as reliably as native ileum, and has a higher complication rate.

Animals↗
PubMed2006

Survey of residency training in laparoscopic and robotic surgery.

PURPOSE: We determined the current status of residency training in laparoscopic and robotic surgery in the United States and Canada. MATERIALS AND METHODS: A total of 1,188 surveys were sent via the Internet to all 1,056 current urology residents and 132 program directors with an Internet address registered with the American Urological Association. RESULTS: Responses were received from 372 residents (35%) and 56 program directors (42%). Of respondents 47% reported greater than 100 laparoscopic procedures performed yearly by 1 (36%) or more (51%) faculty members. Robotic procedures were performed at 54% of the institutions, mainly consisting of prostatectomy and pyeloplasty. At all institutions laparoscopic radical nephrectomy was performed and those at 69% of the institutions believed that it is the gold standard for renal tumors today. Urologists were involved in 87% of adrenal surgeries and 54% of respondents believed that is the gold standard approach. However, only 35% of respondents had participated in laparoscopic adrenalectomy. Of respondents 36%, 42% and 17% reported that laparoscopic donor nephrectomy was performed by only urologists, only a nonurology transplant team and shared equally, respectively. Of respondents 41% planned on performing laparoscopic donor nephrectomy in the next year. Laparoscopic needle ablation renal surgery was done in 51% of the programs and percutaneous needle ablation was done in 63%. None of the respondents (0%) believed that it is the gold standard but 51% believed that ablative procedures look promising for renal tumors. Of respondents 39% had participated in robotic radical prostatectomy and 53% thought that it looked promising but was not the gold standard. Of respondents 31% believed that they will be performing robotic surgery after residency, 30% were unsure and 29% will not be using the robot. Overall 38% of residents thought that their laparoscopic experience was at least average or acceptable. CONCLUSIONS: A large number of laparoscopic urological procedures are being performed at training institutions with robotic procedures being performed at 54% of respondent facilities. Residents are participating in most cases but only 38% consider their laparoscopic experience to be satisfactory. A need still exists for increased laparoscopic training for residents, which can be accomplished by expanding training facilities and increasing the number of faculty members performing laparoscopic procedures.

Adult↗
PubMed2006

Robotic computer-assisted pyeloplasty versus conventional laparoscopic pyeloplasty.

BACKGROUND AND PURPOSE: Laparoscopic pyeloplasty (LP) for the repair of ureteropelvic junction (UPJ) obstruction provides results similar to those of open pyeloplasty with less morbidity, but its use has been limited, as it requires advanced laparoscopic skills. Robotic computer-assisted pyeloplasty (RAP) has the potential to reduce the technical challenges of the reconstructive portion of the operation. We compare our RAP experience with our recent LP cases. PATIENTS AND METHODS: Fourteen patients underwent LP, and 31 underwent RAP. The demographics of the two groups were similar. Three patients in the RAP group had been treated previously for UPJ obstruction. All procedures were performed transperitoneally. For RAP, conventional laparoscopic dissection and exposure preceded robot-assisted reconstruction. A Double-J stent was placed cystoscopically in all patients. Patient demographics and operative, postoperative, and follow-up data were compared. Success was defined strictly as the unequivocal absence of both obstruction and postoperative pain. Also technical success was defined as no evidence of persistent high-grade obstruction, no loss of function, no symptomatic obstruction, and no necessity for further treatment. RESULTS: The diagnosis of UPJ obstruction was confirmed intraoperatively in all cases. No difference was found in operative and postoperative outcomes of the two procedures. Operative time, including cystoscopy, was 299 minutes in the LP group and 271 minutes in the RAP group. The median estimated blood loss was <100 mL in both groups. The median console time for RAP was 76 minutes (range 54-124 minutes) and consisted of preparation and completion of the anastomosis. The median robotic docking and undocking time was 16 minutes (range 5-30 minutes). The anastomotic times for LP were not recorded. There were no conversions to open surgery and no intraoperative complications. The mean length of stay (LOS) was 2 days in both groups. There were two postoperative complications in each group: In the LP group, one large retroperitoneal hematoma and one umbilical hernia; in the RAP group, one nonfebrile urinary-tract infection and one urine leak. The mean follow-up was 10 months (range 1-31 months) for LP and 6 months (range 1-21 months) for RAP. Strict success was seen in 64% of the LP patients and 66% of the RAP patients. There was one technical failure in the RAP group, resulting in a technical success rate of 100% for LP and 97% for RAP. Technical success was seen in two LP patients and five RAP patients with partial obstruction on early postoperative renography and three LP patients and four RAP patients with occasional postoperative pain. CONCLUSION: Robotic computer-assisted pyeloplasty provides short-term results similar to those of conventional laparoscopic pyeloplasty at our institution.

Adolescent↗
PubMed2006

Medical robotics: the impact on perioperative nursing practice.

Robotic technology and the increased use of minimally invasive surgery approaches is altering the environment in which operating room personnel work and affecting how nurses must care for patients. An understanding of the history of robotics, current applications of the technology, and perioperative nursing responsibilities is needed to assure quality patient care in the wake of continued advances in technology.

Forecasting↗
PubMed2006

Care of the patient undergoing robotic-assisted laparoscopic pyeloplasty.

Laparoscopic pyeloplasty as a treatment for ureteropelvic junction obstruction has shown comparable success rates with open pyeloplasty techniques. The use of robotic technology to assist during laparoscopic pyeloplasty procedures has been encouraged by the steep learning curve for laparoscopic surgical skills, and the complexity of laparoscopic suturing. Robotic technology provides the surgeon with the ability to filter out any physiologic hand tremor, more degrees of freedom of movement than traditional laparoscopic instruments, the ability to scale movement to provide better control for microsurgery, better ergonomics during surgery, and three-dimensional vision. Details of the procedure and specific nursing care of the patient undergoing robotic-assisted laparoscopic pyeloplasty at the University of Iowa Hospital and Clinics are described.

Academic Medical Centers↗
PubMed2005

Correlation of preoperative three-dimensional magnetic resonance angiography with intraoperative findings in laparoscopic renal surgery.

BACKGROUND AND PURPOSE: Contrast-enhanced three-dimensional magnetic resonance angiography (3D-MRA) with image reconstruction has important applications in laparoscopic urologic surgery. We now use 3D-MRA as part of our preoperative evaluation in selected patients undergoing laparoscopic donor nephrectomy, pyeloplasty, radical nephrectomy, and partial nephrectomy. PATIENTS AND METHODS: From June 2001 to December 2002, 50 patients underwent preoperative 3D-MRA at 1.5 T prior to laparoscopic renal surgery. In general, preoperative 3D-MRA was obtained for donor nephrectomies and pyeloplasties and for cases where prior imaging suggested a possible vascular anomaly. Patients who underwent preoperative imaging included those having donor nephrectomy (N = 28), pyeloplasty (N = 12), radical nephrectomy (N = 5), partial nephrectomy (N = 3), and other laparoscopic renal procedures (N = 2). The 3D-MRA studies were interpreted by one radiologist, and all laparoscopic cases were performed by one of two surgeons. The findings of 3D-MRA were correlated with the intraoperative findings with special attention to aberrant vasculature, including duplicated renal arteries or veins, accessory vessels, or crossing vessels. RESULTS: Among patients undergoing laparoscopic donor nephrectomy, 3D-MRA correctly predicted the number of renal vessels in 27 of 28 cases (96%), including all 3 cases of left retroaortic renal vein. Also, 3DMRA correctly predicted the presence or absence of a crossing vessel in 10 of 12 cases (83%) of laparoscopic pyeloplasty. The imaging study also correctly predicted the number of hilar vessels in all five cases of radical nephrectomy, all three cases of partial nephrectomy, and both cases of other renal operations. Overall, 3D-MRA correctly defined the renal hilar anatomy in 48 of 50 patients, for an overall accuracy of 96%. CONCLUSIONS: Three-dimensional MRA findings correlate well (96%) with intraoperative findings in laparoscopic renal surgery. The imaging study provides exquisite vascular detail and is highly accurate, making it sufficient imaging prior to laparoscopic donor nephrectomy and useful for pyeloplasty and other complex renal operations.

Chelating Agents↗
PubMed2005

Technique for ensuring negative surgical margins during laparoscopic partial nephrectomy.

BACKGROUND AND PURPOSE: Obtaining a negative surgical margin during laparoscopic partial nephrectomy (LPN) is paramount to optimizing the oncologic efficacy of the procedure. Limitations of laparoscopy hinder the ability to extrapolate the intraparenchymal tumor extension from the exophytic portion. We developed a technique wherein ultrasound-confirmed needle localization of the deep tumor margin prior to tumor extirpation ensured negative surgical margins. MATERIALS AND METHODS: Our technique was developed and initially tested using an agar-based ultrasound phantom designed to mimic 2-cm exophytic renal tumors. Needle placement was imaged with ultrasonography and subsequently correlated with findings on sectioning of the tumor mimic. Laparoscopic extirpation of the tumor mimic following needle placement was carried out in a pelvic trainer. The technique has subsequently been incorporated into our LPN technique in four patients. RESULTS: Ultrasound-confirmed needle localization of intraparenchymal tumor extension was feasible and reproducible in an ultrasound phantom. Ultrasound findings correlated with gross findings. Needle placement prior to tumor resection helped to ensure negative surgical margins when applied in the pelvic trainer and when used in three patients. In the remaining patient, improper needle placement resulted in a grossly positive deep margin. CONCLUSION: Ultrasound-confirmed needle placement effectively and reproducibly marks the deep margin of small renal tumors in a mimic as well as in vivo. Our needle technique eliminates the guesswork and unreliability associated with mental visualization and extrapolation of tumor extent during LPN.

Carcinoma, Renal Cell↗
PubMed2005

Multi-institutional validation study of neural networks to predict duration of stay after laparoscopic radical/simple or partial nephrectomy.

PURPOSE: We developed models to predict post-laparoscopic radical or simple nephrectomy (LapNx) and post-laparoscopic partial nephrectomy (LapPNx) hospital duration of stay (DOS). MATERIALS AND METHODS: We performed a retrospective review (design group) of all 726 patients (July 1997 to April 2004) who underwent LapNx or LapPNx at the Cleveland Clinic Foundation (CCF). Preoperative findings were recorded. Neural network algorithms were designed to predict the DOS before surgery. The models were then tested on a separate 252 patients from 6 different institutions, namely Tulane University Medical School, University of Arkansas for Medical Sciences, Cedars-Sinai Medical Center, University of Iowa, Mayo Clinic at Scottsdale and CCF. RESULTS: In the CCF design groups, the LapNx model accuracy was 73% to 74% and the LapPNx model 73% to 83%. Overall accuracy in the test groups at all 6 institutions was 72% (area under ROC 0.6 to 0.7) for the LapNx model and 52% to 81% (ROC 0.5 to 0.7) for the LapPNx model. CONCLUSIONS: The LapNx model provides 72% accuracy in predicting the DOS at all 6 institutions. The LapPNx model provided fair accuracy only at CCF and Tulane University Medical School. These models may streamline the delivery of care and continued testing will allow for further refinement.

Algorithms↗
PubMed2005

Spontaneous dissolution of a guaifenesin stone.

Guaifenesin is a commonly used expectorant whose use may lead to the occasional formation of guaifenesin urinary stones. We herein describe a patient who was taking 2400 mg Guaifenesin per day as part of his treatment for asthma. He had a past history of a guaifenesin stone removed ureteroscopically. His current presentation was with a 9 mm by 6 mm stone in the upper left ureter, seen on CT scan, and treated initially with a ureteral stent and hydration. After 3 weeks, the stone had disappeared, as confirmed by repeat CT scan. The genesis and treatment of guaifenesin stones is discussed.

Adult↗
PubMed2004

Adrenal adenoma with organizing hematoma: diagnostic dilemma at MRI.

We report a case of adrenal adenoma with organizing hematoma mimicking hemangioma on magnetic resonance imaging (MRI). The lesion demonstrated heterogeneous hyperintensity on heavily T2-weighted images. On dynamic contrasted-enhanced MRI, the lesion demonstrated early, patchy peripheral enhancement with subsequent fill-in that persisted. Chemical shift gradient-echo images failed to demonstrate the presence of intracellular lipid. Magnetic resonance imaging failed to characterize the lesion, and an erroneous preoperative diagnosis of adrenal hemangioma was made. Although the MRI findings reflected the organized hematoma with abundant vascular spaces, our case emphasizes the point that the MRI characteristics of intratumoral hemorrhage may overlap with those of adrenal hemangioma and chronic expanding hematoma.

Adrenal Cortex Neoplasms↗
PubMed2004

Hand-assisted laparoscopic right donor nephrectomy: surgical technique.

Many centers have adopted laparoscopic and hand-assisted laparoscopic (HAL) techniques for live donor nephrectomy. Currently, the majority of laparoscopic living donor kidneys are procured from the left side because of the longer renal vein and improved transplantation. However, indications exist for right donor nephrectomy. We present our technique of HAL right-sided donor nephrectomy. A key feature of our dissection is wide mobilization of adjacent structures to achieve good exposure of the right kidney and inferior vena cava. In addition, the use of the hand permits optimal positioning of the kidney for division of the renal vessels with the vascular stapler. At the time of division of the renal vein, the stapler is placed on the wall of the inferior vena cava in order to gain maximal length. This technique has allowed HAL right-sided donor nephrectomy to be performed safely when indicated.

Humans↗
PubMed2004

Use of bipolar energy for transurethral resection of bladder tumors: pathologic considerations.

BACKGROUND AND PURPOSE: Bipolar electrocautery has recently been introduced as a modality for transurethral resection of bladder tumors (TURBT). The primary benefits of bipolar TURBT stem from the use of saline irrigant rather than glycine or water. TURBT should be conducted in a fashion such that the resected tissue can be used for proper grading and staging, so excessive cauterization of the tissue should be avoided. In this study, we compared the pathologic characteristics of bladder tumor specimens resected with bipolar versus standard monopolar energy to determine specimen quality. PATIENTS AND METHODS: Bipolar TURBT (Gyrus Medical Inc., Maple Grove, MN) was performed in 11 patients. Pathologic specimens were compared with the specimens from 11 patients who had previously undergone standard monopolar TURBT. Resected tissue was examined by a pathologist who recorded tumor size, grade, location, presence of muscularis propria, presence of muscle invasion, and final diagnosis. The pathologist also determined the degree of cautery artifact in each specimen. The pathologist was blinded to the form of electrocautery used and the clinical diagnosis. RESULTS: Transurethral resection with bipolar electrocautery was carried out without difficulty or complication in all cases. Similarly, there were no complications in resection by standard monopolar electrocautery. The bladder tumor chips obtained with bipolar TURBT were smaller because of the smaller size of the bipolar loop. However, this did not interfere with the pathologic assessment. There were no significant pathologic differences between specimens according to the type of cautery used. A large degree of cautery artifact was noted in the tissue of larger tumors resected using both monopolar and bipolar electrocautery. However, the incidence and degree of cautery artifact were similar in the two groups. No trends between tumor location and degree of cautery effect were noted. The pathologist had no difficulty reaching a full and proper diagnosis in all cases involving either form of electrocautery. CONCLUSIONS: Bipolar electrocautery is well suited for TURBT. Bladder tissue obtained from bipolar TURBT is of the same histologic quality as that obtained from standard monopolar TURBT and provides the urologist with a reliable and complete diagnosis.

Electrosurgery↗
PubMed2004

Survey of urological laparoscopic practice patterns in the midwest.

PURPOSE: Laparoscopic surgery is assuming a greater role in the management of many urological disorders. We performed a survey of urologists in the Midwest United States to define laparoscopic practice patterns regarding urological disease. MATERIALS AND METHODS: Surveys were mailed to 1,450 members of the North Central Section of the American Urological Association. Questions pertained to age, practice demographics, residency training and amount of laparoscopy performed. RESULTS: A response rate of 33% was obtained. A total of 49% of urologists perform no laparoscopy, 30% devote less than 5% of their practice and 21% devote 5% or more of their practice to laparoscopy. Of the responders 15% believed they were adequately trained during residency to perform laparoscopy. Among those who performed hand assisted laparoscopy (HAL), 52% used it to gain familiarity with laparoscopic techniques. There was an inverse correlation between time in practice and amount of laparoscopy performed (p <0.0001). Urologists in academia perform laparoscopy at a greater proportion versus those in private practice (p <0.01). Urologists who incorporated laparoscopy during fellowship performed the most laparoscopy (p = 0.003). Those who considered themselves adequately trained during residency were more likely to perform laparoscopy (p <0.0001). Urologists who perform HAL devote more of their operating time to laparoscopy than those who do not (p <0.0001). The number of laparoscopic cases performed correlated with decreased time in practice (p <0.0001), academic setting (p = 0.001) and use of HAL (p <0.0001). CONCLUSIONS: Urological laparoscopic surgery remains at an early stage of development in the Midwestern United States. Although HAL has widened the scope of laparoscopy among urologists, increased training for urologists and residents is necessary.

Adult↗
PubMed2004

Laparoscopic upper pole heminephrectomy for ectopic ureter: initial experience.

OBJECTIVES: To determine the feasibility, clinical outcomes, and complications of laparoscopic upper pole heminephrectomy for ectopic ureter. The standard treatment for a duplex kidney with a poorly functioning upper pole moiety is an upper pole heminephrectomy. We review our technique and experience with laparoscopic upper pole heminephrectomy. A brief review of the literature is provided. METHODS: A retrospective review of clinical records from three patients who underwent laparoscopic upper pole heminephrectomy was performed. Two of the three patients presented with lifelong urinary incontinence and were diagnosed with an ectopic ureter associated with a poorly functioning upper pole moiety. The third patient presented with recurrent episodes of pyelonephritis and was found to have a duplex kidney with a poorly functioning upper pole segment draining into a ureterocele. RESULTS: All three patients underwent laparoscopic upper pole heminephrectomy through the transperitoneal approach. Mean operative time, including ureteral stent insertion, was 198 minutes. Two of the three patients were discharged within 24 hours of surgery. The third patient had a urinary leak secondary to a small amount of residual upper pole parenchyma which resolved with superselective renal arterial embolization. All three patients are well at 5.3 months follow-up. CONCLUSIONS: Laparoscopic upper pole heminephrectomy for ectopic ureter is safe and reproducible and offers the patient the typical postoperative benefits of laparoscopic surgery.

Adolescent↗
PubMed2003

A novel technique to prevent inadvertent sheath migration.

Inadvertent trocar-sheath migration is annoying to the surgeon and may result in serious visceral injury. Herein is described a novel technique to prevent such migration. A 0.25-in. Penrose drain is wrapped around the trocar-sheath unit as a collar to prevent sheath migration.

Foreign-Body Migration↗
PubMed2003

Practice patterns in the treatment of large renal stones.

PURPOSE: To determine the current practice patterns of a large group of urologists in the treatment of large renal stones. MATERIALS AND METHODS: A survey was sent to all actively practicing members of the North Central Section of the American Urological Association. The questions pertained to age, time in practice, type of practice, time devoted to treating stones, residency training, case scenarios with treatment options, and whether they or a radiologist performed percutaneous access. The data were statistically analyzed. RESULTS: The response rate was 51% (564/1102 surveys returned). Three quarters (73%) of the urologists were comfortable performing percutaneous nephrolithotomy (PCNL), and 35% gave reasons they do not perform PCNL. Only 11% of those performing PCNL routinely obtained the percutaneous access themselves. Trends in the analysis included: (1) those trained to perform PCNL during residency were more often comfortable with this procedure; (2) younger urologists were more comfortable performing PCNL, even if they had been in practice for only a short time; (3) urologists in private practice were nearly as comfortable performing PCNL as were academic urologists; (4) urologists not comfortable with PCNL more often recommended SWL over PCNL as a primary treatment for moderate/large renal stones; and (5) few urologists routinely obtained percutaneous access themselves. CONCLUSIONS: Many urologists trained in recent years are comfortable performing PCNL. The type of training received influences treatment recommendations, and percutaneous access is most often obtained by/in conjunction with radiologists. This information may be useful in guiding residency training programs in the preparation of residents for the treatment of large renal stones.

Adult↗
PubMed2003

Laparoscopic upper-pole heminephrectomy for ectopic ureter: surgical technique.

A duplex kidney associated with a poorly functioning upper-pole segment is commonly associated with incontinence, voiding dysfunction, and urinary tract infections. A standard treatment option for this condition is upper-pole heminephrectomy. With the continued development of minimally invasive urology, this technique can now be safely performed laparoscopically. This report details step by step our technique of laparoscopic upper-pole heminephrectomy. Key points include placement of a catheter in the normal ureter at the start of the case, full mobilization of the upper-pole ureter away from the renal hilum, and precise identification of the vasculature supplying the upper pole. Laparoscopic upper-pole heminephrectomy for ectopic ureter is safe and reproducible and offers the patient the typical postoperative benefits of laparoscopic surgery.

Humans↗