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Biomedical subjects

H N Winfield

Publications and source records attributed to H N Winfield.

At least 19 recordsLinked to original sources
PubMed1999

Laparoscopic practice patterns among North American urologists 5 years after formal training.

PURPOSE: We assessed urologist laparoscopy practice patterns 5 years after a postgraduate training course in urological laparoscopic surgery. Results were compared to findings from similar studies performed on the same cohort at 3 and 12 months after training. MATERIALS AND METHODS: Between January 1991 and November 1992, 11, 2-day university sponsored, postgraduate laparoscopic surgery training programs were held. A survey was mailed to the 322 North American participants in the summer of 1997 to determine current laparoscopic use and experience. RESULTS: Of the 166 respondents (51% response rate) 53.6% (89) had performed 1 or more laparoscopic procedures in the previous year, compared to 84% 1 year following course completion. Of the respondents 37% believed their laparoscopic experience was sufficient to maintain skills compared to 66% at 1 year. Of the respondents 6% had performed more laparoscopic procedures while 82% had performed fewer than anticipated. Reasons cited for decreased use included decreasing and/or lack of indications, increased cost, decreased patient interest, higher complication rates, decreased institutional support and increased operative time. Respondents practicing in academic or residency affiliated centers, or those who had completed residency after 1980 were more likely to have performed more procedures than anticipated (p = 0.044) compared to community based colleagues. CONCLUSIONS: Laparoscopic use by urologists trained in the postgraduate setting is decreasing. Few respondents are maintaining the skills acquired during the original training course. Decreased use appears to be multifactorial.

Humans↗
PubMed1998

Laparoscopic adrenalectomy: the preferred choice? A comparison to open adrenalectomy.

PURPOSE: We compare the effectiveness and efficiency of laparoscopic adrenalectomy to open surgical management of adrenal disorders. MATERIALS AND METHODS: A retrospective comparison was undertaken of 21 patients who underwent transperitoneal laparoscopic adrenalectomy between April 1996 and May 1997 with 17 patients who underwent open adrenalectomy between October 1994 and January 1996. Any patient suspected of having primary adrenal carcinoma and/or an adrenal lesion larger than 6 cm. was excluded from the study. RESULTS: Patient demographics were matched well. Mean laparoscopic surgical time was 79 minutes longer than for open surgery. After overcoming the learning curve, the surgical time decreased by 59 minutes in the last 10 laparoscopic adrenalectomies. All laparoscopic intraoperative complications were managed without the need for open surgical conversion. Postoperative characteristics demonstrated significant benefits in the laparoscopic group (p=0.001) with respect to days to return to full diet (1.7 versus 4.6), analgesic pain requirements and days of hospitalization (2.7 versus 6.2). CONCLUSIONS: Laparoscopic adrenalectomy offers significant postoperative benefits to patients with benign adrenal disease requiring surgical intervention. The surgical time is longer than that for open adrenalectomy but there was an encouraging reduction in time after overcoming the laparoscopic learning curve. Laparoscopic adrenalectomy is an excellent choice for tumors smaller than 6 cm. Its role for larger lesions and/or primary adrenal carcinoma is currently under investigation.

Adrenal Gland Neoplasms↗
PubMed1998

Needlescopic adrenalectomy--the initial series: comparison with conventional laparoscopic adrenalectomy.

OBJECTIVES: To report the initial series of needlescopic transperitoneal adrenalectomy and to compare the results with a contemporary series of conventional transperitoneal laparoscopic adrenalectomy performed at the same institution. METHODS: Fifteen patients underwent needlescopic adrenalectomy over a 4-month period. Outcome data were retrospectively compared with 21 conventional laparoscopic adrenalectomies performed over the preceding 12-month period at the same institution. The needlescopic technique included three subcostal ports (two, 2 mm; one, 5 mm) and one umbilical port for ultimate specimen extraction (10/12 mm). The laparoscopic technique included four subcostal ports (all 10/12 mm). Endoscopic transperitoneal adrenalectomy was completed by the standard technique in both groups. RESULTS: Baseline demographics were comparable between the needlescopic (n = 15) and laparoscopic (n = 21) groups. The needlescopic group had a shorter surgical time (169 versus 220 minutes, P = 0.05), less blood loss (61 versus 183 mL, P = 0.002), and shorter hospital stay (1.1 versus 2.7 days, P < 0.001). Convalescence averaged 2.1 weeks in the needlescopic group and 3.1 weeks in the laparoscopic group (P < 0.001). No significant complications occurred in either group. One patient in the needlescopic group was converted to conventional laparoscopy because of marked obesity; hospital stay in this patient was 2 days. CONCLUSIONS: Reported herein is the initial series of needlescopic adrenalectomy. Compared with conventional laparoscopy, needlescopic adrenalectomy results in an overnight hospital stay, rapid recovery, and excellent cosmesis. However, prior experience with conventional laparoscopy is essential before embarking on needlescopic surgery.

Adrenalectomy↗
PubMed1998

Retroperitoneal and pelvic extraperitoneal laparoscopy: an international perspective.

OBJECTIVES: To assess technical preferences and current practice trends of retroperitoneal and pelvic extraperitoneal laparoscopy. METHODS: A questionnaire survey of 36 selected urologic laparoscopic centers worldwide was performed. RESULTS: Twenty-four centers (67%) responded. Overall, 3988 laparoscopic procedures were reported: transperitoneal approach (n = 2945) and retroperitoneal/extraperitoneal approach (n = 1043). Retroperitoneoscopic/extraperitoneoscopic procedures included adrenalectomy (n = 74), nephrectomy (n = 299), ureteral procedures (n = 166), pelvic lymph node dissection (n = 197), bladder neck suspension (n = 210), varix ligation (n = 91), and lumbar sympathectomy (n = 6). Mean number of total laparoscopic procedures performed in 1995 per center was 41 (range 5 to 86). Major complications occurred in 49 (4.7%) patients and included visceral complications in 26 (2.5%) patients and vascular complications in 23 (2.2%). Open conversion was performed in 69 (6.6%) patients, electively in 41 and emergently in 28 (visceral injuries, n = 16; vascular injuries, n = 1 2). Retroperitoneoscopy/extraperitoneoscopy is gaining in acceptance worldwide: in 1993, the mean estimated ratio of transperitoneal laparoscopic cases versus retroperitoneoscopic/ extraperitoneoscopic cases per center was 74:26; however, in 1996 the ratio was 49:51. CONCLUSIONS: Retroperitoneoscopy and pelvic extraperitoneoscopy are important adjuncts to the laparoscopic armamentarium in urologic surgery. The overall major complication rate associated with retroperitoneoscopy/extraperitoneoscopy was 4.7%.

Humans↗
PubMed1998

Laparoscopic retroperitoneal lymphadenectomy for cancer of the testis.

Laparoscopic retroperitoneal lymph node dissection (RPLND) is a technically advanced procedure that has been undertaken for the management of low-stage nonseminomatous germ cell testis tumor. Although it has been shown to be an effective staging technique, its role as a therapeutic operation is currently unknown. Laparoscopic RPLND requires longer operative times but offers the patient all the advantages of minimally invasive surgery, such as less postoperative pain and shorter hospitalization and convalescence. The role of laparoscopic RPLND for the evaluation of residual abdominal masses following chemotherapy is currently being examined.

Humans↗
PubMed1998

Increased intra-abdominal pressure during pneumoperitoneum stimulates endothelin release in a canine model.

Prolonged pneumoperitoneum during laparoscopic surgery has been associated with oliguria in clinical experimental studies. Although the pathophysiology of this oliguria is thought to be renal parenchymal and venous compression, the role of the potent vasoconstrictor endothelin (ET) has not been studied. The purpose of this study was to investigate the effect of pneumoperitoneum on endothelin release and renal function in a canine model. Two groups of dogs were studied during pneumoperitoneum (Group 1, N = 7) or isolated left renal vein compression (Group 2, N = 6). Urine and plasma samples were collected for urine output, glomerular filtration rate (GFR), urine sodium, and plasma endothelin measurements. In Group 1, GFR fell significantly (p < 0.05) by 49% from a control of 0.88 +/- 0.12 mL/min per gram of kidney weight. Urine volume fell by 79% (p < 0.05) from a control value of 0.014 +/- 0.003 mL/min/gkw. Sodium excretion was decreased by 88%. Sodium reabsorption was significantly enhanced during pneumoperitoneum (99.56 +/- 0.15% v 98.44 +/- 0.25%). Arterial plasma ET concentrations were elevated by 8% during the first 20 minutes of pneumoperitoneum (30.8 +/- 3.6 v 33.3 +/- 3.4 pg/mL; p < 0.05). In Group 2, left renal vein compression resulted in a 31% decrease (p < 0.05) in GFR in the left kidney and a 25% decrease in the right kidney. Urine volume fell by 67% in the left kidney and 40% in the right. Renal venous ET concentrations also increased after renal vein compression. Although the mechanism by which oliguria occurs during pneumoperitoneum is not fully understood, the ET concentration was elevated. Because ET can decrease RBF, GFR, and sodium excretion, it may contribute to the oliguria observed during long periods of pneumoperitoneum.

Abdomen↗
PubMed1997

Effect of laparoscopic pelvic lymph node dissection on the natural history of D1 (T1-3, N1-3, M0) prostate cancer.

OBJECTIVES: Reports of abdominal wall tumor implantation after laparoscopic procedures have raised questions regarding the safety of laparoscopic surgery when applied to patients with malignancies. Our objective was to determine if laparoscopic pelvic lymph node dissection (LPLND) had a negative effect on tumor behavior and clinical outcome in men with Stage T1-3, N1-3, M0 (D1) prostate cancer. METHODS: Fifty-two men were retrospectively identified at four institutions who had pelvic nodes positive for metastatic prostate adenocarcinoma at LPLND and at least 1 year of follow-up. Operative and clinical records were reviewed to determine morbidity, adjuvant treatment, onset of hormone-resistant disease, and survival. RESULTS: During a mean follow-up of 3.1 years, there were no cases of trocar site tumor implantation. There were four perioperative complications, including enterotomy, epigastric vessel injury, abscess, and symptomatic lymphocele formation. There were three deaths from prostate cancer (5.8%) occurring 3 to 4 years after LPLND. For the 45 men treated with early androgen ablation, the 5-year biochemical prostate-specific antigen and clinical progression free rates were 45% and 55%, respectively. CONCLUSIONS: Abdominal wall tumor implantation after LPLND for prostate cancer was not demonstrated, even in patients who developed hormone-resistant disease. LPLND in men with Stage D1 disease did not alter short-term disease progression. Longer follow-up in a larger cohort is necessary to determine if LPLND will have an impact on the 5 and 10-year disease progression and survival rates for patients with Stage D1 prostate cancer.

Disease Progression↗
PubMed1997

Technique of laparoscopic adrenalectomy.

Laparoscopic adrenalectomy by the transperitoneal route has been shown to be a safe and effective approach to select adrenal pathology. Although the specific indications will continue to be refined, it is clear that for adrenal masses of 6 cm or less, laparoscopy provides excellent access with little additional risk to the patient. In addition there appears to be an improved postoperative course when compared with open adrenalectomy. This latter point, however, requires careful prospective studies to confirm this impression objectively. The operative times are longer by the laparoscopic approach, but undoubtedly these times will decrease with increasing experience and improved laparoscopic instrumentation.

Adrenalectomy↗
PubMed1997

Laparoscopic nephrectomy of a horseshoe kidney.

The role of laparoscopic surgery in the treatment of benign renal diseases continues to evolve with the development of equipment and refinement of techniques. A minimally invasive approach to the treatment of these lesions offers several advantages, including shorter convalescence. We describe the first laparoscopic nephrectomy involving a horseshoe kidney.

Adult↗
PubMed1997

Hip and knee replacement as a relative contraindication to laparoscopic pelvic lymph node dissection.

PURPOSE: We investigated the effect of lower extremity joint prostheses on subsequent laparoscopic pelvic lymph node dissection. MATERIALS AND METHODS: We reviewed the records and pathology studies of 5 patients who underwent laparoscopic pelvic lymph node dissection subsequent to total hip or knee replacement from 1990 through 1995. RESULTS: Four of the 5 laparoscopic operations were complicated, 3 were unsuccessful in obtaining bilateral pelvic lymph nodes and 2 required conversion to an open procedure. Examination of the lymph nodes revealed sinus histiocytosis in the 4 cases in which nodal tissue was removed. CONCLUSIONS: The increased risk of complications in certain patients with lower extremity joint prostheses may contraindicate attempted laparoscopic pelvic lymph node dissection.

Aged↗
PubMed1997

Laparoscopic pelvic lymph node dissection following definitive radiotherapy for carcinoma of the prostate.

PURPOSE: Laparoscopic pelvic lymph node dissection is an effective and minimally invasive approach to the clinical staging of adenocarcinoma of the prostate. We report our experience with this technique in patients in whom full course pelvic radiotherapy had failed and who were being considered for salvage local therapy. MATERIALS AND METHODS: In 14 patients disease was staged by transperitoneal laparoscopic pelvic lymph node dissection performed for persistent adenocarcinoma of the prostate at least 20 months (average 49.5) following external beam radiotherapy and/or brachytherapy. All patients were healthy, had no evidence of metastatic disease and were considered to be candidates for salvage therapy. RESULTS: A total of 13 patients underwent successful laparoscopic pelvic lymph node dissection while 1 sustained an enterotomy requiring conversion to open surgery. The normal surgical planes were more difficult to dissect, with the obturator lymph node packets appearing smaller and more fibrotic than in nonirradiated patients, yielding an average of 7.1 total nodes. Average operative time was 167 minutes and postoperative hospitalization was comparable to reported series of nonirradiated patients. Four patients (28%) with metastatic pelvic lymph nodes underwent subsequent orchiectomy. Nine patients with negative lymph nodes underwent ultrasound guided transperineal placement of radioactive gold or palladium seeds. One patient underwent salvage radical retropubic prostatectomy. CONCLUSIONS: Laparoscopic pelvic lymph node dissection following full course pelvic irradiation is technically feasible, albeit more difficult than in nonirradiated patients. This approach appears to be an excellent minimally invasive technique for the clinical restaging of persistent adenocarcinoma of the prostate in patients being considered for salvage therapy.

Adenocarcinoma↗
PubMed1997

Role of laparoscopic surgery in pediatric urology.

OBJECTIVES: In our clinic, laparoscopy was introduced in 1987 for the exploration of non-palpable testes and since 1991 it has also been applied with therapeutic aims. We present our experience with this minimally invasive technique in pediatric patients. PATIENTS AND METHODS: Between May 1987 and September 1996, 219 laparoscopic procedures were performed in children. All children received general anesthesia. Positioning of the patient on a rotatable and tiltable operating table is very important. RESULTS: All laparoscopic interventions were well tolerated in children. The operative time for exploration of a nonpalpable testis ranged from 10 to 30 min, and for varix ligation from 15 to 30 min. In nephrectomy and nephroureterectomy cases 80-150 min were required. The excision of the urachal remnant and the drainage of lymphocele took between 30 and 70 min. No immediate postoperative complications were observed. Mobilization and oral intake were routinely carried out on the day of surgery. The children required little or no postoperative pain medication. CONCLUSION: Laparoscopy has been found to be the most reliable diagnostic tool in evaluating nonpalpable testes within the pediatric population. This approach enables subsequent therapy of laparoscopic orchiectomy, primary laparoendoscopic orchidopexy, or laparoscopically assisted two-stage Fowler-Stephens maneuver. Laparoscopic varix ligation is a simple and highly effective treatment modality for the pubescent male with a symptomatic varicocele. To date, the recurrence rate is 1.8% based on 80 patients followed for over 1 year. Fenestration of lymphoceles following renal transplantation has been found to be as efficaciously treated with laparoscopy as with open surgery. Laparoscopic nephrectomy and/or nephroureterectomy are technically demanding procedures and should only be performed by an experienced laparoscopic surgical team to minimize the complication rate. At the present time, the intraoperative costs of laparoscopic surgery are greater than with open surgery due to the use of disposable instrumentation and longer operating room times. However, minimally invasive surgery continues to gain a greater and more important role in the field of pediatric urology.

Adolescent↗
PubMed1996

Laparoscopic urethral sling for treatment of intrinsic sphincter deficiency.

The surgical treatment of intrinsic sphincter deficiency, or Type III genuine stress urinary incontinence, has traditionally been accomplished by sling cystourethropexy, the placement of an artificial urinary sphincter, or periurethral injection. We developed a laparoscopic approach for the performance of a sling cystourethropexy as an alternative to the open approach and herein describe our experience. We have found that a laparoscopic sling cystourethropexy is feasible, but at the present time, we have been unable to demonstrate any significant advantages to the patient in terms of decreased cost or convalescence compared with the open vaginal sling cystourethropexy.

Female↗
PubMed1996

Carbon dioxide homeostasis during transperitoneal or extraperitoneal laparoscopic pelvic lymphadenectomy: a real-time intraoperative comparison.

The primary goal of this study was to evaluate differences in carbon dioxide metabolism between patients undergoing transperitoneal or extraperitoneal laparoscopic pelvic lymph node dissection (L-PLND) for staging of adenocarcinoma of the prostate (CaP). Eighteen candidates undergoing L-PLND were divided between the transperitoneal (N = 12) and extraperitoneal (N = 6) approaches. End-tidal partial pressure of CO2 (PeCO2) and minute volume of expired CO2 (VCO2) were considered indicators of CO2 absorption. These two parameters were monitored intraoperatively utilizing a metabolic cart and Ohmeda Rascal-II. The cardiostimulatory effect of increasing serum CO2 and the ventilatory countermeasures used to correct the iatrogenic hypercapnia associated with CO2 insufflation were also measured. With the exception of the region of CO2 insufflation, the operative procedure and perioperative care were identical for the two groups. Preoperative patient characteristics were similar. The mean time of CO2 insufflation was 136 minutes for the transperitoneal group and 120 minutes for the extraperitoneal group. The absorption of CO2 was significantly greater and more rapid during extraperitoneal L-PLND. This may be attributable to more profound CO2 absorption from the parietal peritoneal surface compounded by subcutaneous CO2 emphysema. Disruption of microvascular and lymphatic channels during the development of the extraperitoneal working space facilitates direct CO2 absorption into the intravascular space. A minor increase in heart rate and systolic blood pressure was noted during CO2 insufflation. In all but one patient (extraperitoneal group), hypercarbia and acidemia were prevented by an increased ventilatory rate. The potential dysrhythmogenicity of hypercarbia may contraindicate the extraperitoneal approach in patients with cardiopulmonary disease.

Adenocarcinoma↗
PubMed1996

Comparative financial analysis of laparoscopic pelvic lymph node dissection performed in 1990-1992 v 1993-1994.

In 1994, it was reported that laparoscopic pelvic lymph node dissection (L-PLND) was US $1350 more expensive than open pelvic lymph node dissection (O-PLND) for the staging of prostate cancer. Despite the lower postoperative expenses associated with L-PLND, the intraoperative expenditures were 52% higher, primarily because of the prolonged operating time and the cost of disposable instrumentation. The objective of the present study was to determine if, with increasing laparoscopic experience and a more competitive surgical supply market, the intraoperative as well as the overall hospital expenses would diminish. The study population consisted of 105 men who underwent staging L-PLND for cancer of the prostate. Group I was composed of 50 patients who underwent surgery between 1990 and 1992, and Group II consisted of 55 patients operated on in 1993 and 1994. All hospital-related expenses were reorganized into preoperative, intraoperative, and postoperative and subsequently corrected for inflationary changes to a base year of 1993-1994. The total overall expenses of the two groups were similar, differing by only $65. Despite a lowering of preoperative and postoperative expenses in the 1993-1994 group by 112% and 31%, respectively, the intraoperative expenses were still $571 higher. The operative time decreased by 19 minutes in the contemporary group, but the expense of surgical supplies continued to increase up to $910 (104%) more than the 1990-1992 group. It is hoped that the use of "laparoscopic kits" as well hospital equipment consortiums will help slow the escalating costs of surgical care. However, it is the responsibility of the laparoscopic surgeon to demonstrate that these procedures are as safe, efficient, and cost-effective as their open counterpart.

Aged↗
PubMed1996

Sequential laparoscopic bladder diverticulectomy and transurethral resection of the prostate.

The surgical treatment of prostatic obstruction associated with a clinically significant bladder diverticulum has classically combined open diverticulectomy with relief of the bladder outlet obstruction. This report demonstrates that this result may be efficiently achieved by performing transurethral surgery followed immediately by laparoscopic excision of the diverticulum. As assessed by a retrospective comparison with four open bladder diverticulectomies combined with transurethral resection of the prostate, laparoscopic diverticulectomy markedly reduces the postoperative and convalescence period. The overall financial saving that ensues may benefit both the patient and the healthcare system. Sequential laparoscopic bladder diverticulectomy and transurethral resection of the prostate illustrates the increasing possibilities of minimally invasive surgery.

Aged↗
PubMed1996

Laparoscopic marsupialization of pelvic lymphoceles.

Pelvic lymphoceles are a known complication of urologic surgery. Often, these are small and asymptomatic and require no specific therapy. When large or symptomatic, the treatment of choice is controversial, but includes needle aspiration, percutaneous drainage, sclerotherapy, open surgical marsupialization or, most recently, laparoscopic marsupialization. The laparoscopic technique described herein has been performed successfully by many urologists and is accepted as a standard laparoscopic procedure. Because of its efficacy and its low morbidity, laparoscopic marsupialization may be considered a first-line treatment for pelvic lymphoceles.

Humans↗