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Biomedical subjects

M D Dunn

Publications and source records attributed to M D Dunn.

17 recordsLinked to original sources
PubMed2001

Laparoscopic management of retrovesical cystic disease: Washington University experience and review of the literature.

BACKGROUND AND PURPOSE: Recently, the laparoscopic approach to the management of seminal vesicle cysts has been described. This report outlines the Washington University experience and reviews the present literature to evaluate the results of the laparoscopic approach to the excision of retrovesical cysts of seminal vesicle and Müllerian origin. PATIENTS AND METHODS: The hospital and office records of three patients undergoing laparoscopic excision of seminal vesicle and Müllerian duct cyst disease between April 1993 and March 1999 were reviewed for the operative time, the estimated blood loss, total hospital stay, total analgesia required postoperatively, the time to resumption of oral intake, and the postoperative recovery. A literature search revealed two additional reports of laparoscopic management of cystic disease of the seminal vesicle, comprising only one and two patients. An additional review of the literature was performed to compare the laparoscopic procedure with the transvesical, transurethral, open transvesical, and open retrovesical approach for the management of the disease. RESULTS: For the three patients at Washington University, the operative time averaged 4 hours (range 1.8-6.1 hours), and the mean estimated blood loss was 150 mL (range 50-200 nL). The patients required a mean of 43 mg of morphine sulfate for postoperative pain control, had a mean hospital stay of 2.6 days, and resumed oral intake 5.8 hours postoperatively. In combination with the three other cases reported in the literature, the average operative time for laparoscopic retrovesical cyst excision was 2.9 hours, and the average hospital stay was 2.2 days. With an average follow-up of 17 months, all six patients had excellent resolution of their preoperative symptoms. There have been no major or minor complications or any need for further operative therapy. CONCLUSION: Laparoscopic excision of retrovesical cystic disease is an effective surgical procedure, associated with minimal postoperative morbidity, short hospitalization, and a rapid recovery for the patient.

Adult↗
PubMed2001

Laparoscopic cyst marsupialization in patients with autosomal dominant polycystic kidney disease.

PURPOSE: Autosomal dominant polycystic kidney disease is characterized by progressively enlarging renal cysts associated with hypertension, renal failure, pain, hematuria and infection. We explored the role of laparoscopic cyst marsupialization for managing cyst related problems. MATERIALS AND METHODS: In 4 male and 11 female adults with autosomal dominant polycystic kidney disease who had preserved renal function laparoscopic cyst marsupialization was done for pain unilaterally and bilaterally in 9 and 6, respectively. An average of 204 cysts per kidney (range 11 to 635) were decorticated or drained. RESULTS: Average operative time was 5.5 hours. Patients were discharged from the hospital after an average of 3.2 days. At a mean followup of 2.2 years (range 0.5 to 5) pain was decreased an average of 62% (range 30% to 90%) in 11 cases (73%). One patient had no improvement and 1 had subsequent worsening of pain postoperatively. Two patients with initial improvement had pain recurrence 4 and 36 months postoperatively, respectively. Hypertension resolved in 1 patient (7%), improved in 20% and did not change in 40%. In 33% of the cases hypertension worsened, requiring additional antihypertensive medication. Renal function remained stable in 13 patients (87%), improved in 1 (6.5%) and worsened in 1 (6.5%). Overall patients who underwent a bilateral procedure had better long-term pain relief and more improvement in hypertension. CONCLUSIONS: Laparoscopic cyst marsupialization may effectively decrease cyst associated pain. In some cases hypertension may be improved. Renal function remained stable in all except 1 patient. At a mean followup of 2.2 years the benefits of aggressive laparoscopic cyst decortication appear to be relatively long lasting when bilateral decortication is indicated. The benefits of unilateral cyst decortication are less predictable and of shorter duration.

Adult↗
PubMed2000

Laparoscopic management of renal cystic disease.

Renal cystic disease, ranging from simple cysts to autosomal dominant polycystic kidney disease (ADPKD), can lead to significant complications such as pain, hypertension, infection, upper urinary tract obstruction, and even renal failure. For patients with preserved renal function, laparoscopic ablation of renal cysts is a recent, though safe and effective alternative to open surgery in patients who have failed conservative measures. Likewise, for symptomatic patients with renal failure, laparoscopic nephrectomy offers a less invasive option to open nephrectomy. Both laparoscopic cyst decortication and laparoscopic nephrectomy offer patients the benefits of minimal intraoperative blood loss, minimal postoperative pain, brief hospital stay, and rapid convalescence while offering a short-term outcome equivalent to open surgery. Further study and follow-up are indicated to assess the long-term effect of these procedures on the outcome of ADPKD with regard to durability of pain relief, preservation of renal function, and impact on renal hypertension.

Humans↗
PubMed2000

Survey of neuromuscular injuries to the patient and surgeon during urologic laparoscopic surgery.

OBJECTIVES: Laparoscopy may be complicated by neuromuscular injuries, both to the patient and to the surgeon. We used a survey to estimate the incidence of these injuries during urologic laparoscopic surgery, to assess risk factors for these injuries, and to determine preventive measures. METHODS: A survey of neuromuscular injuries associated with laparoscopy submitted to 18 institutions in the United States was completed by 18 attending urologists from 15 institutions. RESULTS: From among a total of 1651 procedures, there were 46 neuromuscular injuries in 45 patients (2.7%), including abdominal wall neuralgia (14), extremity sensory deficit (12), extremity motor deficit (8), clinical rhabdomyolysis (6), shoulder contusion (4), and back spasm (2). Neuromuscular injuries were twice as common with upper retroperitoneal as with pelvic laparoscopy (3. 1% versus 1.5%). Among patients with neuromuscular injuries, those with rhabdomyolysis were heavier (means 91 versus 80 kg) and underwent longer procedures (means 379 versus 300 minutes), and those with motor deficits were older (means 51 versus 42 years of age). Of the surgeons, 28% and 17% reported frequent neck and shoulder pain, respectively. CONCLUSIONS: Although not common, neuromuscular injuries during laparoscopy do contribute to morbidity. Abdominal wall neuralgias, injuries to peripheral nerves, and joint or back injuries likely occur no more frequently than during open surgery, but risk of rhabdomyolysis may be increased. Positioning in a partial rather than full flank position may reduce the incidence of some injuries. Measures to reduce neuromuscular strain on the surgeon during laparoscopy should be considered.

Abdominal Muscles↗
PubMed2000

Renal physiology. Laparoscopic considerations.

Oliguria is a recognized component of the physiologic effect of increased intra-abdominal or retroperitoneal pressure. The cause is multifactorial, emanating from vascular and parenchymal compression, and is associated with systemic hormonal effects. Ureteral obstruction does not play a significant role. These changes are pressure-dependent and are usually not apparent until pressures reach 15 mm Hg or more. This effect is not associated with any histologic pathology or evidence of renal tubular damage. After the release of the pneumoperitoneum or pneumoretroperitoneum, the renal function and urine output return to normal with no long-term sequelae, even in patients with pre-existing renal disease. The entire operative team must understand the physiologic effects of CO2 insufflation, which allows appropriate intraoperative monitoring and management and minimizes intraoperative and postoperative complications.

Animals↗
PubMed2000

Laparoscopic nephrectomy in patients with end-stage renal disease and autosomal dominant polycystic kidney disease.

Autosomal dominant polycystic kidney disease (ADPKD) is often characterized by end-stage renal disease (ESRD) and problems including pain, hematuria, and infection. Open nephrectomy is curative; however, the morbidity of the procedure is considerable. Between 1995 and 1998, 11 laparoscopic nephrectomies were performed on nine symptomatic patients (five men and four women) with ESRD and ADPKD. Two patients underwent a staged bilateral laparoscopic nephrectomy. All patients presented with abdominal or flank pain and an abdominal mass. Other clinical problems included hypertension in eight patients, urinary tract infections in two patients, and gross hematuria in one patient. Seven patients were receiving long-term dialysis treatment, and two patients had undergone prior renal transplantation. Patients were evaluated for preoperative and postoperative pain, analgesic use, hospital course, and convalescence. The overall average operative time was 6.3 hours, with an average estimated blood loss of 153 mL. Eight nephrectomy specimens were removed by morcellation, and three specimens were removed intact through a 7- to 12-cm incision. The average hospital stay was 3 days, and the average time to normal activity was 5 weeks. With a mean follow-up of 31 months, all nine patients reported elimination of their preoperative pain based on a pain analogue score. Six major and two minor complications occurred, including blood transfusion, a vena cavotomy, splenic cyanosis, pulmonary embolism, clotted arteriovenous fistula, and brachial plexus injury. Incisional hernias occurred in two of the three patients who underwent open removal. One patient noted improvement, and two patients noted resolution of their hypertension postoperatively. Laparoscopic nephrectomy in patients with ADPKD and ESRD offers an effective alternative to open nephrectomy to manage renal-related pain. This procedure provides the benefits of minimal intraoperative blood loss, minimal postoperative pain, brief hospital stay, and rapid convalescence.

Aged↗
PubMed2000

Clinical effectiveness of new stent design: randomized single-blind comparison of tail and double-pigtail stents.

BACKGROUND AND PURPOSE: Stent morbidity appears to be secondary to lower urinary tract irritation. In an effort to decrease stent morbidity, a "one size fits all" Tail stent (Microvasive [Boston Scientific] Natick, MA) was developed with a 7F proximal pigtail and 7F shaft which tapers to a lumenless straight 3F tail. PATIENTS AND METHODS: We randomized 60 patients in a single-blind fashion to a 7F tail stent or 7F double-pigtail Percuflex stent. Patients were evaluated at the time of stent removal and 2 weeks later with a standardized questionnaire assessing: irritative lower tract symptoms individually and on a total scale of 0 (no symptoms) to 30 (worst symptoms), obstructive lower tract symptoms (on a total scale of 0-20), and upper tract irritative symptoms (on a total scale of 0-10). RESULTS: Patient age, weight, and height were similar in the two groups. Complications, including fever, urinary tract infections, emergency room visits, and the need for antispasmodics and pain medication, also demonstrated no significant difference. At the time of stent removal, patients who received a tail stent had significantly less urinary frequency and a statistically significant (21%) decrease in overall irritative voiding symptoms (12.2 v 15.4; p = 0.048). Two weeks after stent removal, the total irritative voiding symptoms was markedly decreased in both groups (7.1 in the Tail v 5.3 in the double-pigtail group; p = 0.15). Obstructive bladder and flank symptoms were not significantly different in the two stent groups, either at the time of stent removal or at 2 weeks after removal. CONCLUSION: In this randomized, single-blind study, the 7F Tail stent produced significantly less irritative symptoms than did the standard 7F double-pigtail stent. Obstructive symptoms tended to be less with the new stent, while flank symptoms were similar.

Adult↗
PubMed2000

Laparoscopic nephropexy: long-term follow-up--Washington University experience.

BACKGROUND AND PURPOSE: Recently, laparoscopy has been reported as a minimally invasive approach for performing nephropexy in patients with symptomatic nephroptosis. Herein, we report our long-term follow-up of patients undergoing laparoscopic nephropexy for this indication. PATIENTS AND METHODS: Fourteen women presenting with right flank pain and radiologically documented nephroptosis underwent transperitoneal laparoscopic nephropexy. The hospital data were evaluated for operative time, time to oral intake, time to ambulation, amount of parenteral analgesics, and hospital stay. Pain analog scores and postoperative questionnaires were used to assess the long-term postoperative recovery of the patients. RESULTS: The average operative time was 4.1 hours (range 2.5-6.5 hours). The patients resumed oral intake an average of 16.5 hours (range 15-48 hours) postoperatively. Analgesic requirements averaged 37 mg of morphine sulfate equivalent (range 15-80 mg of morphine equivalent). The average hospital stay was 2.6 days (range 2-5 days). The average follow-up time for the 14 patients was 3.3 years, with an average 80% improvement in their pain (range 56%-100%). On average, the patients resumed their usual activities 6 weeks postoperatively (range 1-12 weeks). CONCLUSION: Nephropexy can be safely and effectively accomplished laparoscopically, with durable radiographic and clinical resolution of the signs and symptoms.

Adult↗
PubMed2000

Laparoscopic radical nephrectomy.

Although open nephrectomy is the standard of care for localized renal-cell carcinoma, the significant postoperative pain and lengthy convalescence have encouraged the use of laparoscopy, which can yield similar 2- to 5-year survival rates. Either a transperitoneal or a retroperitoneal approach may be used, and sometimes, they are combined. Generally, the technique is limited to tumors <10 cm, but larger tumors can be removed. Nitrous oxide is avoided as an anesthetic agent. The dissection follows accepted oncologic principles: in situ renal dissection within Gerota's fascia, early ligation of the renal vessels, and careful removal of the specimen to prevent tumor spillage. Dissection of the hilum is facilitated by a PEER retractor and an Endoholder. On average, patients having laparoscopic radical nephrectomy return to normal activities approximately 4.5 weeks sooner than those having open surgery, a fact not taken into account in cost analyses. Laparoscopic nephrectomy may offer a special benefit in patients with known metastatic disease, as interleukin-2 administration can be started a month earlier than after open surgery. There may also be immunologic benefits of minimally invasive v open surgery. The technique and instruments continue to evolve, and cost-effectiveness should continue to improve.

Biopsy↗
PubMed2000

Laparoscopic nephroureterectomy for upper tract transitional cell cancer: the Washington University experience.

PURPOSE: Laparoscopic nephroureterectomy has only recently been done to treat patients with upper tract transitional cell carcinoma. We retrospectively evaluated our experience with and long-term followup of laparoscopic nephroureterectomy, compared our results to those of contemporary series of open nephroureterectomy and reviewed the literature. MATERIALS AND METHODS: We reviewed the charts of and followed up by telephone 25 patients who underwent laparoscopic nephroureterectomy between May 1991 and June 1998, and 17 who underwent open nephroureterectomy between March 1990 and January 1997. Demographic, perioperative and followup data were compared. We performed a MEDLINE search and reviewed the literature on laparoscopic nephroureterectomy for upper tract transitional cell carcinoma. RESULTS: Laparoscopic nephroureterectomy required twice the operating time of open nephroureterectomy (7.7 versus 3.9 hours). However, patients who underwent the laparoscopic procedure had a 74% decrease in analgesia requirements (37 versus 144 mg. morphine sulfate equivalent), a 63% shorter hospital stay (3.6 versus 9.6 days) and a 72% more rapid convalescence (2.8 versus 10 weeks). Subsequent bladder transitional cell carcinoma and overall cancer specific survival were similar at a mean followup of 2 years. There was no sign of trocar site or peritoneal seeding after laparoscopic nephroureterectomy. CONCLUSIONS: Although laparoscopic nephroureterectomy is a longer operation, it has the same efficacy and is better tolerated by patients than open nephroureterectomy for upper tract transitional cell carcinoma. As operating time decreases due to surgeon experience and the recent development of hand assisted laparoscopy, laparoscopic nephroureterectomy may soon become the procedure of choice for the ablative management of upper tract transitional cell carcinoma.

Adult↗
PubMed2000

Laparoscopic versus open radical nephrectomy: a 9-year experience.

PURPOSE: The laparoscopic approach for renal cell carcinoma is slowly evolving. We report our experience with laparoscopic radical nephrectomy and compare it to a contemporary cohort of patients with renal cell carcinoma who underwent open radical nephrectomy. MATERIALS AND METHODS: From 1990 to 1999, 32 males and 28 females underwent 61 laparoscopic radical nephrectomies for suspicious renal cell carcinoma. Clinical data from a computerized database were reviewed and compared to a contemporary group of 33 patients who underwent open radical nephrectomy for renal cell carcinoma. RESULTS: Patients in the laparoscopic radical nephrectomy group had significantly reduced, estimated blood loss (172 versus 451 ml., p <0.001), hospital stay (3.4 versus 5.2 days, p <0.001), pain medication requirement (28.0 versus 78.3 mg., p <0.001) and quicker return to normal activity than patients in the open radical nephrectomy group (3.6 versus 8.1 weeks, p <0.001). The majority of laparoscopic specimens (65%) were morcellated. Operating time and cost were higher in the laparoscopic than the open nephrectomy group. Average followup was 25 months (range 3 to 73) for the laparoscopic and 27.5 months (range 7 to 90) for the open group. Renal cell carcinoma in 3 patients (8%) recurred in the laparoscopic group versus renal cell carcinoma in 3 (9%) in the open group. When stratified patients with tumors larger than 4 to 10 cm. experienced similar benefits and results as patients with tumors less than or equal to 4 cm. To date there have been no instances of trocar or intraperitoneal seeding in the laparoscopic radical nephrectomy group. CONCLUSIONS: Laparoscopic radical nephrectomy, although technically demanding, is a viable alternative for managing localized renal tumors up to 10 cm. It affords patients with renal tumors an improved postoperative course with less pain and a quicker recovery while providing similar efficacy at 2-year followup for patients with T1 and T2 tumors.

Adult↗
PubMed2000

Flexible ureteroscopes: a single center evaluation of the durability and function of the new endoscopes smaller than 9Fr.

PURPOSE: Flexible ureteroscopes smaller than 9Fr are widely used in endourology. We systematically evaluated the functional durability of these instruments in the clinical setting. MATERIALS AND METHODS: We performed ureteronephroscopy 92 consecutive times in 84 patients at our hospital using a flexible Storz model 11274AA,double dagger Circon-ACMI model AUR-7, section sign Wolf model 7325.172 parallel and Olympus model URF/P3 ureteroscope paragraph sign. Preoperatively and postoperatively we evaluated all flexible ureteroscopes for luminosity, irrigant flow at 100 mm. Hg, number of broken image fibers and active deflection range. During the procedure a record was kept of the duration that the endoscope remained in the urinary tract, average irrigation pressure, method of insertion, various devices used within the working channel, need for lower pole access, and surgeon overall impression of visibility and maneuverability. RESULTS: The luminosity and irrigant flow of all endoscopes remained relatively unchanged during consecutive applications, while active deflection deteriorated 2% to 28%. Endoscopes were used for an average of 3 to 13 hours before they needed repair. The most fragile part of these instruments was the deflection unit. CONCLUSIONS: Small diameter flexible ureteroscopes are effective for diagnosing and treating upper urinary tract pathology but improved durability is required. Currently they represent a highly effective but high maintenance means of achieving retrograde access to the ureter and kidney with a need for repair after only 6 to 15 uses.

Equipment Design↗
PubMed2000

Laparoscopic nephrectomy and nephroureterectomy for renal and upper tract transitional cell cancer.

The best management for renal tumors is surgical excision. The laparoscopic technique of radical or total nephrectomy for renal cell carcinoma and radical nephroureterectomy for transitional cell carcinoma is rapidly gaining momentum as an effective method of extirpative surgery. The transperitoneal and retroperitoneal approach to either of these procedures is proving to be equally effective to open surgery with respect to tumor removal, providing similar disease-free rates. Laparoscopic surgery leads to a significantly lower intraoperative blood loss, postoperative analgesic requirement, and quicker convalescence. Presently the only drawbacks to laparoscopic surgery are longer operative times and higher costs. Fortunately, these factors are slowly approaching those of open surgery because of increased experience, improved instrumentation, and modification of the surgical technique.

Carcinoma, Transitional Cell↗
PubMed1998

Elevated and absent pRb expression is associated with bladder cancer progression and has cooperative effects with p53.

Rb protein (pRb) expression was evaluated in 185 cases of transitional cell carcinoma of the bladder from patients that underwent radical cystectomy. Tumors were stratified into three categories based on the percentage of nuclei expressing pRb: (a) 0, 0% of tumor cells showing nuclear reactivity; (b) 1+, 1-50% of tumor cells showing nuclear reactivity; and (c) 2+, >50% of tumor cells showing nuclear reactivity. Cases with undetectable (pRb 0) and high (pRb 2+) pRb reactivity had identical rates of recurrence. These cases had significantly higher recurrence (P = 0.0001) and lower survival rates (P = 0.0002) compared to cases with moderate (pRb 1+) pRb reactivity, indicating that high levels of pRb expression may reflect a dysfunctional (altered) Rb pathway. The tumors were also examined for alterations in p53 expression; patients with tumors altered in both p53 and pRb had significantly increased rates of recurrence (P < 0.0001) and survival (P < 0.0001) compared to patients with no alterations in either p53 or pRb; patients with alterations in only one of these proteins had intermediate rates of recurrence and survival. These results suggest that: (a) bladder cancers with high pRb expression do not show the tumor suppressor effects of the protein; and (b) alteration in both p53 and pRb may act in cooperative or synergistic ways to promote tumor progression.

Carcinoma, Transitional Cell↗
PubMed1998

An acute scrotum following a laparoscopic appendectomy.

We report a case of a 13-year-old boy who developed an acute left hemiscrotum following a laparoscopic appendectomy for a perforated appendicitis. Laparoscopic techniques have provided surgeons and their patients with effective and less invasive methods to treat illness that previously required open surgery. However, complications can occur with these new surgical modalities. It is incumbent upon the surgeon to carefully document and evaluate these complications, facilitating preventive measures, and allow for a proper and timely diagnosis and treatment plan in the future. Herein, we present a previously unreported urologic complication of an acute scrotum following a laparoscopic appendectomy for a perforated appendicitis.

Adolescent↗