Luke Chang - Academia.edu (original) (raw)

Papers by Luke Chang

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Urologia Internationalis, 1993

We used a modified chemolytic solution by combining 0.1 M THAM (tris[hydroxymethyl] aminomethane)... more We used a modified chemolytic solution by combining 0.1 M THAM (tris[hydroxymethyl] aminomethane) with 0.02% chlorhexidine to treat 10 obstructive uric acid stone patients. A total of 23 local chemolysis sessions were performed. Five patients received 13 sessions (average: 2.6) as an adjuvant chemolysis after extracorporeal shock wave lithotripsy 5 patients received 10 sessions (average: 2) as a primary treatment. The average time of local chemolysis was 2.3 days, ranging from 1 to 4 days. In the 23 local chemolysis sessions, only one patient developed two episodes of fever (8.7%), which were managed successfully by conservative treatment. The mean values of effective renal plasma flow of treated kidney was increased from 108.2 to 155.6 ml/min (p < 0.05). The stone-free rate assessed by IVP and ultrasonography at 3 months follow-up was 80%. Our results indicate that the combined use of 0.1 M THAM and 0.02% chlorhexidine is an effective and safe method to treat obstructive uric acid stones.

Urologia Internationalis, 2006

Few studies have examined the voiding pattern of healthy females, despite the importance of such ... more Few studies have examined the voiding pattern of healthy females, despite the importance of such research for diagnosing abnormal voiding behavior. This study investigates the voiding behavior of healthy women in Taiwan. 68 healthy women, aged 19-66 years and claiming to void normally were enrolled. Twenty-two of the subjects (32.4%) were postmenopausal. Each woman completed a 3-day voiding diary. The diary recorded urine volume, voiding frequency, urine volume per voiding for the whole day (24 h), and urine volume during both daytime and nighttime. Age and various other voiding parameters were correlated, and the voiding patterns were compared between premenopausal and postmenopausal women. All women voided 7.34 +/- 1.63 times daily. Higher age was associated with higher whole day and daytime voiding frequency. Nocturia was not common for the group as a whole, with a mean nocturnal voiding of 0.25 times per night. However, higher age was significantly associated with a higher nighttime voiding frequency. A significantly positive correlation was also observed between age and whole day urine volume. Compared with regularly menstruating women, postmenopausal women had a significantly higher whole day and nighttime voiding frequency. Menopause and age both independently affect voiding parameters after multivariate analysis. The results of this study provide invaluable baseline data on female voiding behavior. Additionally, this study found that for healthy women, age and menstruation status significantly affect voiding patterns. Analysis of female voiding behavior thus should consider these two factors.

Urology, 1995

Femoral neuropathy is an uncommon complication following pelvic surgery. We report on 2 cases of ... more Femoral neuropathy is an uncommon complication following pelvic surgery. We report on 2 cases of femoral nerve injury after pelvic surgery: 1 patient received radical cystectomy due to invasive transitional cell carcinoma of the urinary bladder, and the other patient had a transurethral resection of the bladder and r-e ceived exploration and biopsy of a tumor mass over the right sacroiliac joint area. Pathogenesis and prevention of the complication of femoral neuropathy are discussed in the following report. UROLKX~ 46: 575-576, 1995.

Urology, 2006

Objectives. To conduct a prospective study to determine the causes of nocturia in men. Methods. T... more Objectives. To conduct a prospective study to determine the causes of nocturia in men. Methods. The study included 41 male patients (mean age 72.5 years) bothered by nocturia (two or more micturitions per night). Eleven asymptomatic young men (mean age 28.4 years) were enrolled as a control group. All completed a 3-day voiding diary. Daytime and nighttime urine samples were collected to determine osmolality and sodium and potassium levels. Urodynamic studies were performed for all patients with nocturia to evaluate for bladder outlet obstruction using the International Continence Society definition. Polysomnography was performed on selected patients to detect sleep apnea. Results. The average nighttime voiding frequency was 3.9 in the patients with nocturia. Nocturnal polyuria (NP) was found in 34 (82.9%) of 41 patients. In these patients, the nighttime urinary sodium excretion was significantly greater than the daytime excretion, with lower nighttime urine osmolality. In contrast, nighttime and daytime sodium excretion was not significantly different in patients without NP, and greater nighttime urine osmolality was noted in the patients without NP and the control group. Of the 41 patients, 24 (58.5%) had a small nocturnal bladder capacity, with detrusor overactivity in 14 of 24 patients. Eighteen patients (43.9%) had both NP and a small nocturnal bladder capacity. Another 18 patients had bladder outlet obstruction and NP. Two patients had sleep apnea. Conclusions. Our observations have shown that a significant contributor to male nocturia is NP, which results from a disordered diurnal rhythm of sodium excretion and other unknown factors causing nocturnal urinary dilution. However, male nocturia can also be secondary to a combination of factors. Detailed workup is necessary to elucidate all causes. UROLOGY 67: 541-544, 2006.

The Journal of Urology, 2012

International Journal of Urology, 1999

Background: Persistent postchemotherapy retroperitoneal residual mass with normalization of a-fet... more Background: Persistent postchemotherapy retroperitoneal residual mass with normalization of a-fetoprotein (AFP) in infantile yolk sac tumor is rare. Methods/Results: A 38-month-old boy with recurrent yolk sac tumor was treated with cisplatin-based combination chemotherapy. After chemotherapy, the retroperitoneal lymph node metastasis, 7 ¥ 6 cm in size, decreased to 2 ¥ 2 cm. Serum AFP levels returned to normal. The retroperitoneal residual mass was resected and histologically showed complete necrosis without viable cancer cells.

British Journal of Urology, 1992

Laparoscopic procedures have long been a standard form of treatment for gynaecological disorders ... more Laparoscopic procedures have long been a standard form of treatment for gynaecological disorders but have only recently shown promise in the evaluation and treatment of urogenital diseases, such as pelvic lymphadenectomy. We performed laparoscopic ligation of the bilateral internal spermatic veins in 15 male pigs. The average operative time was 20 min and operative morbidity was minimal, comprising mild subcutaneous emphysema around the trocars. Engorgement of the spermatic vein proximal to the endoclip site was noted. There was no operative mortality. Laparoscopic ligation of the internal spermatic veins seems to be a feasible method for the treatment of varicoceles, especially bilateral lesions.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Scandinavian Journal of Urology and Nephrology, 1991

A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESW... more A prospective evaluation of 89 consecutive sessions of extracorporeal shock wave lithotripsy (ESWL) was undertaken to try and find the best way of minimising the amount of exposure to radiation. Forty-two patients were randomly allocated to undergo ESWL treatment by experienced surgeons (group A), and 47 to undergo the treatment by inexperienced surgeons (group B). The mean calculated entrance radiation exposure was 3.01 rads (group A: 2.64 (0.97) rads, range 1.00-4.48, group B: 3.38 (0.86) rads, range 1.11-5.75). Among factors that influenced radiation exposure, the tissue: air ratio should be borne in mind and the level of skill in controlling movement of gantry was the most important in reducing the exposure to radiation.

Urologia Internationalis, 1993

We used a modified chemolytic solution by combining 0.1 M THAM (tris[hydroxymethyl] aminomethane)... more We used a modified chemolytic solution by combining 0.1 M THAM (tris[hydroxymethyl] aminomethane) with 0.02% chlorhexidine to treat 10 obstructive uric acid stone patients. A total of 23 local chemolysis sessions were performed. Five patients received 13 sessions (average: 2.6) as an adjuvant chemolysis after extracorporeal shock wave lithotripsy 5 patients received 10 sessions (average: 2) as a primary treatment. The average time of local chemolysis was 2.3 days, ranging from 1 to 4 days. In the 23 local chemolysis sessions, only one patient developed two episodes of fever (8.7%), which were managed successfully by conservative treatment. The mean values of effective renal plasma flow of treated kidney was increased from 108.2 to 155.6 ml/min (p < 0.05). The stone-free rate assessed by IVP and ultrasonography at 3 months follow-up was 80%. Our results indicate that the combined use of 0.1 M THAM and 0.02% chlorhexidine is an effective and safe method to treat obstructive uric acid stones.

Urologia Internationalis, 2006

Few studies have examined the voiding pattern of healthy females, despite the importance of such ... more Few studies have examined the voiding pattern of healthy females, despite the importance of such research for diagnosing abnormal voiding behavior. This study investigates the voiding behavior of healthy women in Taiwan. 68 healthy women, aged 19-66 years and claiming to void normally were enrolled. Twenty-two of the subjects (32.4%) were postmenopausal. Each woman completed a 3-day voiding diary. The diary recorded urine volume, voiding frequency, urine volume per voiding for the whole day (24 h), and urine volume during both daytime and nighttime. Age and various other voiding parameters were correlated, and the voiding patterns were compared between premenopausal and postmenopausal women. All women voided 7.34 +/- 1.63 times daily. Higher age was associated with higher whole day and daytime voiding frequency. Nocturia was not common for the group as a whole, with a mean nocturnal voiding of 0.25 times per night. However, higher age was significantly associated with a higher nighttime voiding frequency. A significantly positive correlation was also observed between age and whole day urine volume. Compared with regularly menstruating women, postmenopausal women had a significantly higher whole day and nighttime voiding frequency. Menopause and age both independently affect voiding parameters after multivariate analysis. The results of this study provide invaluable baseline data on female voiding behavior. Additionally, this study found that for healthy women, age and menstruation status significantly affect voiding patterns. Analysis of female voiding behavior thus should consider these two factors.

Urology, 1995

Femoral neuropathy is an uncommon complication following pelvic surgery. We report on 2 cases of ... more Femoral neuropathy is an uncommon complication following pelvic surgery. We report on 2 cases of femoral nerve injury after pelvic surgery: 1 patient received radical cystectomy due to invasive transitional cell carcinoma of the urinary bladder, and the other patient had a transurethral resection of the bladder and r-e ceived exploration and biopsy of a tumor mass over the right sacroiliac joint area. Pathogenesis and prevention of the complication of femoral neuropathy are discussed in the following report. UROLKX~ 46: 575-576, 1995.

Urology, 2006

Objectives. To conduct a prospective study to determine the causes of nocturia in men. Methods. T... more Objectives. To conduct a prospective study to determine the causes of nocturia in men. Methods. The study included 41 male patients (mean age 72.5 years) bothered by nocturia (two or more micturitions per night). Eleven asymptomatic young men (mean age 28.4 years) were enrolled as a control group. All completed a 3-day voiding diary. Daytime and nighttime urine samples were collected to determine osmolality and sodium and potassium levels. Urodynamic studies were performed for all patients with nocturia to evaluate for bladder outlet obstruction using the International Continence Society definition. Polysomnography was performed on selected patients to detect sleep apnea. Results. The average nighttime voiding frequency was 3.9 in the patients with nocturia. Nocturnal polyuria (NP) was found in 34 (82.9%) of 41 patients. In these patients, the nighttime urinary sodium excretion was significantly greater than the daytime excretion, with lower nighttime urine osmolality. In contrast, nighttime and daytime sodium excretion was not significantly different in patients without NP, and greater nighttime urine osmolality was noted in the patients without NP and the control group. Of the 41 patients, 24 (58.5%) had a small nocturnal bladder capacity, with detrusor overactivity in 14 of 24 patients. Eighteen patients (43.9%) had both NP and a small nocturnal bladder capacity. Another 18 patients had bladder outlet obstruction and NP. Two patients had sleep apnea. Conclusions. Our observations have shown that a significant contributor to male nocturia is NP, which results from a disordered diurnal rhythm of sodium excretion and other unknown factors causing nocturnal urinary dilution. However, male nocturia can also be secondary to a combination of factors. Detailed workup is necessary to elucidate all causes. UROLOGY 67: 541-544, 2006.

The Journal of Urology, 2012

International Journal of Urology, 1999

Background: Persistent postchemotherapy retroperitoneal residual mass with normalization of a-fet... more Background: Persistent postchemotherapy retroperitoneal residual mass with normalization of a-fetoprotein (AFP) in infantile yolk sac tumor is rare. Methods/Results: A 38-month-old boy with recurrent yolk sac tumor was treated with cisplatin-based combination chemotherapy. After chemotherapy, the retroperitoneal lymph node metastasis, 7 ¥ 6 cm in size, decreased to 2 ¥ 2 cm. Serum AFP levels returned to normal. The retroperitoneal residual mass was resected and histologically showed complete necrosis without viable cancer cells.

British Journal of Urology, 1992

Laparoscopic procedures have long been a standard form of treatment for gynaecological disorders ... more Laparoscopic procedures have long been a standard form of treatment for gynaecological disorders but have only recently shown promise in the evaluation and treatment of urogenital diseases, such as pelvic lymphadenectomy. We performed laparoscopic ligation of the bilateral internal spermatic veins in 15 male pigs. The average operative time was 20 min and operative morbidity was minimal, comprising mild subcutaneous emphysema around the trocars. Engorgement of the spermatic vein proximal to the endoclip site was noted. There was no operative mortality. Laparoscopic ligation of the internal spermatic veins seems to be a feasible method for the treatment of varicoceles, especially bilateral lesions.