Biomedical subjects

Y T Moon

Publications and source records attributed to Y T Moon.

13 recordsLinked to original sources

PubMed1998

Prevalence and risk factors of urinary stones in Koreans.

To estimate the prevalence of urinary stone disease in Koreans, and to determine the inter-relationships between urinary stone disease and various epidemiological factors, 1,521 controls and 1,177 cases with urinary stones were evaluated. Of special interest in this study were: 1) proportion of past urinary stone history among controls; 1.9% 2) the point prevalence rate of urinary stones among controls; 0.2% 3) the recurrence rate of urinary stones (the proportion of past history of urinary stone) among cases; 56.8% 4) high incidences (76.3%) in the thirties to the fifties among cases 5) the risk factors for urolithogenesis; obesity [higher than 25 of BMI (body mass index, weight/height2)], more than 10 year-experience as a production worker, past stone history, familial stone history, low physical activity (< 2,000 Kcal/day), and low intake of fruit. However, the well-known risk factors for urinary stones; over intake of meat or fish and milk or dairy products, perspiration, amount and kind of drinking water, and stress unexpectedly were not significantly different between the controls and the cases.

Adolescent↗

PubMed1997

Experience with EDAP LT02 extracorporeal shockwave lithotripsy in 1363 patients: comparison with results of LT01 SWL in 1586 patients.

A new piezoelectric lithotripter, the EDAP LT02, differs from the earlier LT01 in two important respects: a stone-localization system consisting of ultrasound and fluoroscopy and more energy per shockwave. The results of SWL monotherapy with the LT02 in 1363 patients and with the LT01 in 1586 patients who completed SWL treatment were compared. All of the stones could be localized by ultrasound (62.7%), fluoroscopy (0.3%), or both (37%) on the LT02, but the renal stones of three patients who had a history of open renal surgery and 29 upper ureteral stones could not be localized by real-time ultrasound on the LT01. The success rate (stone free or residual fragments < 4 mm in diameter) with the LT02 and LT01 according to stone location was not significantly different: 86.4% and 88.5%, respectively, for renal stones, 89.1% and 88.9% for ureteral stones, and 87.0% and 89.0% overall. The overall stone-free rate of LT02 and LT01 SWL was 78.8% and 87.9%, respectively. For mid-ureteral stones, the success rate with LT02 SWL was 76.8%. (Such stones were not an indication for LT01 SWL.) The mean number of treatment sessions with the LT02 (1.9) was much less (P < 0.001) than with the LT01 (3.3). The retreatment rates of LT02 and LT01 SWL were 68.2% and 198.2%, and the auxiliary treatment rates were 3.4% and 6.3%, respectively. Thus, the efficiency quotient was 45.9% in LT02 SWL, which was much higher than the 28.9% of the LT01. There was no significant difference in the occurrence of complications between LT02 and LT01 SWL. Therefore, LT02 piezoelectric lithotripsy is more efficient than the LT01 in localizing stones and can lessen the number of treatment sessions.

Adolescent↗

PubMed1997

Laparoscopic mobilization of the inferior epigastric artery for penile revascularization in vasculogenic impotence.

A laparoscopic approach was used for penile revascularization in a patient with vasculogenic impotence to avoid the long abdominal incision which was traditionally required to harvest the inferior epigastric artery as a neoarterial source. Despite the time-consuming nature of laparoscopy, this procedure was as efficacious but less morbid and required less convalescence than open revascularization. Whether more patients may benefit from this procedure must be evaluated in further studies.

Epigastric Arteries↗

PubMed1996

Laparoscopic bladder seromyotomy: laboratory experience.

Twelve female microminipigs with normal bladder capacity underwent laparoscopic bladder seromyotomy. Three other female microminipigs were added to the study as controls. Urodynamic studies and cystograms were performed preoperatively and at 2 and 4 months after a laparoscopic bladder seromyotomy. Histologic studies of the treated bladders were performed when the animals were euthanized at 4 months. The operation was completed in all 12 test animals. There was no significant difference in bladder capacity or leak-point pressure between the 12 seromyotomy and the 3 control bladders at any time point. Histologically, over the seromyotomy site, the urothelium remained intact; however, the muscularis was attenuated, and a thin layer of fibrotic tissue replaced the normal serosal covering of the bladder. Laparoscopic bladder seromyotomy can be performed reliably in the porcine animal model. Not surprisingly, no significant changes in bladder capacity or bladder compliance were seen in our study of normal bladders. An animal model of a neuropathic contracted bladder is needed to assess more accurately the physiological impact of laparoscopic seromyotomy.

Animals↗

PubMed1996

The unintubated ureterotomy endourologically revisited.

PURPOSE: The duration of stenting after endoureterotomy is a controversial issue. An even more basic question, however, is whether stent placement is needed at all. We performed a porcine study to address this question. METHODS: A unilateral midureteral stricture was created in 20 minipigs. Six weeks later, 15 pigs underwent endoureterotomy. In 10 animals, a 7F ureteral stent was placed for 1 week. Five pigs remained unstented. Three months later, all 20 ureters were studied radiographically and were harvested. RESULTS: Three of 5 control animals and 2 of 10 stented animals has strictures. In the unstented study group, all 5 animals had a nonobstructing dilation at the site of endoureterotomy. This was corroborated by a normal furosemide washout renal scan in all 3 animals so tested. CONCLUSIONS: The result of unstented endoureterotomy in the porcine model suggests that, after endoureterotomy of secondary midureteral strictures, stenting may be unnecessary.

Animals↗

PubMed1995

Evaluation of optimal stent size after endourologic incision of ureteral strictures.

The stent size necessary to promote optimal ureteral healing after an endoureterotomy is not known. We compared healing of an endoureterotomy over a 7F indwelling ureteral stent with healing over a 14F endopyelotomy stent. A midureteral stricture was created in each of 25 anesthetized female minipigs using an electrified stone basket passed retrograde. Six weeks later, the stricture was incised with a 24F cutting balloon device. Twenty pigs were randomized to receive a 7F or a 14F stent; four control pigs received neither incisions nor stents. At 1 week, a radiograph was performed to confirm proper stent position, and the stents were removed. At 3 months, a retrograde ureterogram was performed, and the ureters were examined grossly and harvested for histologic studies. Two of the ten pigs in each study group developed a recurrent stricture. The use of a 14F stent provided no advantage over the use of a smaller, more easily positioned 7F stent.

Animals↗

PubMed1995

A giant ureteral stone.

A 55-year-old woman suffered from right flank pain and had a right giant ureteral stone with hydronephrosis. Ureterolithotomy was performed. The ureteral stone was 11cm long and weighed 45gm.

Female↗

PubMed1995

Laparoscopic pneumodissection: a unique means of tissue dissection.

PURPOSE: To study the acute and chronic tissue effects of using high pressure CO2 to dissect tissues during laparoscopic procedures. MATERIALS AND METHODS: A 5-mm. laparoscopic pneumodissector, capable of delivering brief bursts of high pressure CO2 (20 to 100 psi), was discharged on a variety of porcine tissues including the renal hilum. Acute and chronic histological sections, intraoperative blood gases and perioperative renal scans were obtained. RESULTS: The only tissue with significant acute damage was the spleen. Acute changes in other tissues were minimal; long-term studies revealed no discernible damage to these same tissues. Intraoperative blood gases revealed no significant changes in the serum pCO2 or pH. Likewise, there was no renal damage discernible by renal scans. CONCLUSIONS: Pneumodissection at 50 psi is a safe method for dissecting the porcine kidney and the vessels of the renal hilum. Clinical studies are pending.

Animals↗

PubMed1994

Comparison of retrograde endo-pyelotomy and endo-balloon rupture of the ureteropelvic junction in a porcine model.

Excellent results and durable success have been achieved with antegrade and retrograde endo-pyelotomy for treating primary and secondary ureteropelvic junction obstruction. Recently, a 30F dilating balloon was used to rupture the ureteropelvic junction (ENDOBRST) with encouraging results. While balloon distention of the ureteropelvic junction is a technically simpler procedure than endo-pyelotomy, clinical and laboratory data comparing the 2 methods are lacking. In an acute and chronic animal study we compared endo-pyelotomy via a ureteral cutting balloon incision to balloon rupture (that is 30F) of the normal ureteropelvic junction in each of 20 female farm pigs. Eight pigs were harvested acutely after treatment, and a macroscopic and histological examination of the treated ureteropelvic junction was completed. In 11 chronic pigs after endo-pyelotomy a 7F double pigtail ureteral stent was placed bilaterally and then removed after 6 weeks. Evaluation in the chronic group consisted of a furosemide washout renogram and retrograde pyelogram immediately preoperatively and 6 weeks after stent removal. The animals were likewise harvested 6 weeks after stent removal. One control pig underwent passage of the balloon cutting catheter and balloon dilating catheters without activation or dilation, respectively. Ureteral stents were placed bilaterally for 6 weeks and the pig was otherwise treated similarly to the other chronic study animals. In the acute group all ureters after endo-pyelotomy demonstrated retroperitoneal extravasation of contrast material. At harvest the ureters had been cleanly incised along a length of 3 to 4 cm. through the adventitial layer. In contrast, the balloon treated ureters showed free retroperitoneal extravasation in only half of the animals. Among the balloon treated ureters 7 of 8 had a linear tear of varying length (1 to 5 cm.) involving all but a thin adventitial layer of tissue. Histologically, the endo-pyelotomy ureters demonstrated a clean, linear transmural incision with virtually no destruction of surrounding tissue in 6 cases. In the remaining 2 cases an incision into but not completely through the muscular layer was observed. The balloon treated ureters showed a perforation through the muscular wall in 7 cases. However, periureteral hemorrhage and urothelial loss were common findings. In the chronic group infection and continued urine extravasation from the endo-pyelotomy site resulted in a 45% mortality rate. Of the surviving 6 pigs 83% of the balloon treated and 67% of the endo-pyelotomy pigs had a patent ureteropelvic junction by retrograde pyelogram and renogram. Histologically, the 2 sides were indistinguishable, with both showing mild fibrosis and chronic inflammation.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1994

Non-visualization versus normal appearance of cavernous arteries on selective internal pudendal pharmaco-angiograms: comparison with duplex scanning, cavernosal artery systolic occlusion pressure and penile brachial index.

OBJECTIVE: To determine whether selective internal pudendal pharmaco-angiography (SIPA) is the most reliable diagnostic procedure for evaluating the function of the cavernosal arteries. PATIENTS AND METHODS: Both sides of the selective internal pudendal pharmaco-angiogram taken in 35 patients (70 cases), whose history was suggestive of post-traumatic arteriogenic impotence, were evaluated separately and compared to the corresponding side using the penile brachial index (PBI), duplex scanning and cavernosal artery systolic occlusion pressure (CASOP). RESULTS: There was no significant difference in the peak flow velocity and diameter changes of the cavernosal arteries on duplex scanning, in pressure differences between the brachial artery systolic pressure and the CASOP, and in the PBI between the group with a normal appearance on SIPA and the other where the cavernosal arteries were not visualized. There was no significant difference in the results of these functional evaluations between the normal group and cases where the cavernosal arteries were not visualized accompanied by a completely obstructed internal pudendal artery or common penile artery visible on SIPA. CONCLUSIONS: This study is unable to confirm the value of SIPA in evaluating the function of the cavernosal arteries as it provides only anatomical information.

Adult↗

PubMed1993

Fate of clinically insignificant residual fragments after extracorporeal shock wave lithotripsy with EDAP LT-01 lithotripter.

The stone-free rate of 248 cases of clinically insignificant residual fragments (CIRF) was 32.7% by 1 month, 73.0% by 3 months, and 92.7% by 6 months of follow-up. The stone-free rate decreased but not remarkably in accordance with the increment of the caliceal dilatation (92.9%, 94.9%, 85.7%, and 83.3% for no, mild, moderate, and severe dilatation, respectively) by 6 months of follow-up. The clearance of the CIRF was not influenced by their location, the pelviocaliceal angle, the infundibular length, or the number of the lower calices. Of 16 patients who had residual stone fragments at 6 months and underwent an additional session of extracorporeal shock wave lithotripsy (SWL), 12 became stone free by another 6 months of follow-up. Therefore, it is desirable to wait for clearance of CIRF for at least 6 months before offering further treatment, regardless of their location and anatomic variation of the calices containing CIRF. Repeated SWL, even for stone fragments of 3 to 4 mm in diameter found initially 1 month after the last session of SWL, might promote clearance of the CIRF, and additional SWL for persistent CIRF could be an appropriate adjunctive measure.

Adolescent↗

PubMed1991

Treatment of steinstrasse with repeat extracorporeal shock wave lithotripsy: experience with piezoelectric lithotriptor.

Among 958 patients with renal stones who underwent extracorporeal shock wave lithotripsy (ESWL) monotherapy using an EDAP-LT01 piezoelectric lithotriptor steinstrasse developed in 55 (5.7%). Of these 55 cases stone fragments passed spontaneously in 35 (63.6%) and were treated successfully (no residual stone fragment in ureter) with repeat ESWL in 18 (32.8%). Only 2 patients (3.6%) required ureteroscopic management or open ureterolithotomy. Therefore, repeat ESWL is considered a good initial method to treat complicated steinstrasse.

Humans↗

PubMed1989

Extracorporeal shock wave lithotripsy monotherapy: experience with piezoelectric second generation lithotriptor in 642 patients.

Extracorporeal shock wave lithotripsy monotherapy was performed in 642 patients for 1 year with an EDAP-LT01 piezoelectric lithotriptor. Of 642 patients 398 completed extracorporeal shock wave lithotripsy treatment and 244 still are undergoing multiple extracorporeal shock wave lithotripsy sessions. The 398 patients had renal (64.6 per cent) or ureteral (35.4 per cent) stones 0.6 to 4.8 cm. in diameter (mean 1.4 cm.). No general or regional anesthesia was required except in 7 children. Among 398 patients who completed extracorporeal shock wave lithotripsy the rate free of stones was 73.4 per cent and the rate of clinically insignificant residual fragments was 12.8 per cent. The success rate (rate free of calculi plus that of clinically insignificant renal fragments) ranged from 95.6 per cent for stones 0.6 to 1.0 cm. in diameter to 52.6 per cent for stones larger than 3.0 cm. (mean 86.2 per cent). The number of treatment sessions in 343 patients with successful results increased in accordance with the stone size, with an average of 1.6 sessions. Double-J* stents were placed in 7 patients and ureteral catheterization was performed in 11 as post-extracorporeal shock wave lithotripsy adjunctive measures. The steinstrasse phenomenon was noted in 14 patients, of whom only 1 required Double-J stenting. There were no significant complications. Therefore, extracorporeal shock wave lithotripsy monotherapy with the piezoelectric lithotriptor is considered to be a safe and efficient outpatient procedure for the initial treatment of urinary stones regardless of stone sizes.

Adolescent↗