Biomedical subjects
Publications and source records attributed to A W Chiu.
A retroperitoneal laparoscopic nephrectomy was performed utilizing a novel three-dimensional laparoscope. This case report illustrates the potential benefits of this new technology for complex laparoscopic procedures.
An animal model was established to study the effects of elevated intra-abdominal pressure (IAP) on systemic and renal hemodynamics during laparoscopy. In a pilot study in five dogs, we simultaneously recorded carotid artery blood flow (CABF), carotid artery blood pressure (CABP), inferior vena caval pressure (IVCP), renal parenchymal blood flow, and IAP. The renal parenchymal blood flow was measured by a laser Doppler flowmetry (LDF) needle probe and the renal artery blood flow by an ultrasonic Doppler probe, both placed through laparotomy. The reliability and reproducibility of these two measurements at different renal perfusion pressures were documented. The established method was then used to assess the effects of increased IAP on renal hemodynamics during laparoscopy in six pigs. Pneumoperitoneum was achieved by insufflating the abdominal cavity with air. The LDF needle probe was inserted into the renal parenchyma laparoscopically. An increase in IAP from 0 to 40 mm Hg did not influence CABP. However, significant decreases in CABF were seen from 190.8 +/- 59.5 mL/min at 0 mm Hg IAP to 169 +/- 43.6 mL/min at 15 mm Hg. The CABF decreased in a linear fashion as IAP was increasing (correlation coefficient R = 0.976). Renal cortical blood flow (RCBF) decreased from 50.1 +/- 17.7 mL/min per 100 g at 0 mm Hg to IAP to 21.2 +/- 9.6 mL/min per 100 g of tissue at 15 mm Hg. There was an exponential correlation between IAP and RCBF (R = 0.897).(ABSTRACT TRUNCATED AT 250 WORDS)
The influence of oestrogen on spermatogenesis was evaluated by comparing its effect on the testes of primary male transsexuals and those who had undergone hormone therapy for prostatic carcinoma. Eight primary transsexuals were studied. They had been diagnosed on clinical and psychiatric evidence and had been on oestrogen therapy for several years since puberty. Histological sections of testicular tissue obtained at reassignment surgery from 8 phenotypic male transsexuals (aged 24-32 years) with an XY chromosome complement were studied by light microscopy. The formalin-embedded specimens were analysed by flow cytometry for deoxyribonucleic acid (DNA) histograms. Both the histology and DNA histograms revealed a pattern of maturation arrest in 12 of 16 testes in which the diploid cell compartment occupied most of the spermatogenetic element, followed by tetraploid and monoploid cells. Two testes showed impaired spermatogenesis and 2 were normal. The DNA histograms and pathology were also evaluated in 20 testes after 3 to 8 years of hormone therapy in patients with advanced prostatic carcinoma (aged 60-78 years). No maturation arrest was found in these patients. Sixteen of them had a pattern of fibrosis and atrophy and 4 had impaired spermatogenesis. It was concluded that oestrogen influenced spermatogenesis and affected the maturation of spermatogonia mostly during puberty.
Laser iridotomy is a safe and effective treatment of pupillary-block glaucoma; however, increased intraocular pressure (IOP) may occur after the procedure. A flow cytometric study of aqueous humor was done 1.5 hours after neodymium: yttrium aluminum garnet laser iridotomy in 20 eyes. This sensitive and precise method did not reveal an apparent correlation between the degree of postoperative IOP spike and the amount of inflammatory cells or cellular debris induced by laser iridotomy. Although slit-lamp examination showed many "cells" in the anterior chamber in most after laser iridotomy, DNA histography found only scanty chromatin coating cells. We believe the so-called cells observed using slit-lamp biomicroscopy might not all be real cellular aggregates but rather aggregates of protein or fibrin in some situations.
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.
Laparoscopic nephrectomy was performed in 15 male pigs, the procedure was successful in 14. Extraction of the intact kidney through a 5-cm lower abdomen incision was done in 7 animals; complete destruction and evacuation of the kidney was accomplished by a round-knife suction device through a 1-cm port in another 7 pigs. Grossly, the specimen consisted of sausage-like tubular renal tissue and a small amount of tissue debris. Pathology revealed that the glomerular and tubular structures were well preserved, no interstitial hematoma could be found. Four ports were usually used, one 1-cm umbilical camera port, one 0.5-cm port for ureter traction, and two 1-cm working ports along the midclavicular line. All the pigs recovered uneventfully. The average operation time was 3 h 20 min. The application of endo-GIA (United States Surgical Corporation) for renal hilum reduced the operative time to 2 h 20 min. Complications included renal vein tear during endoclip application and cutting in the first case, mild subcutaneous emphysema in 2 cases. This first pig received exploratory laparotomy for the repair and ligation of the renal vein. No more major complications occurred with increasing experience. From this porcine experiment, we conclude that the combination of laparoscopy, a tissue destroyer and an endobag for the entrapment of kidney seem to be a promising technique for clinical nephrectomy.
Laparoscopic procedures have recently been used in the evaluation and treatment of some urogenital diseases. A case of right intraabdominal cryptorchism associated with left varicocele was successfully treated by laparoscopic orchiectomy and ligation of the contralateral internal spermatic vein concomitantly. This new technology can be easily performed and has the advantages of less tissue trauma, easy application for bilateral lesions, and less patient morbidity. We consider laparoscopy is a promising method for the diagnosis and treatment of intraabdominal testis.
From March to July 1989, a total of 40 patients, who had received coronary catheterization, answered questionnaires concerning sexual potency. In those 30 patients with a diseased coronary artery, only 2 (6.6%) had no erectile dysfunction subjectively. On the contrary, 4 of 10 (40%) patients with angiographically proven normal coronary artery complained of erectile dysfunction. Penile Doppler ultrasonography was performed in 30 patients. The mean penile brachial index (PBI) of 8 patients with a normal coronary artery was 0.82 +/- 0.1, as compared with the diseased group, 0.73 +/- 0.1 (p = 0.05). When these patients were further divided into two groups by a PBI of greater or less than 0.65, there was also no significant difference in the degree of obstruction of the three main coronary arteries between these two groups. There was no correlation between PBI and obstruction of the left anterior descending artery (r = 0.316, p = 0.689). Most of the patients (93.4%) with an abnormal coronary artery had erectile dysfunction. Nevertheless a poor correlation was noted between the PBI and the severity of coronary artery obstruction. Our study suggests that it is hard to use PBI alone as a predictor of future major thromboembolic heart attack.
Six high operative risk patients with urinary retention caused by benign prostatic hyperplasia were managed with an intraprostatic spiral at our hospital. Three of them had severe coronary artery disease, 1 had uremia, 1 had cerebral stroke and 1 had poorly controlled diabetes mellitus. The urinary retention was successfully relieved by the intraprostatic spiral in all patients. No operative mortality or severe complication was encountered. One patient experienced a repeat attack of urinary retention due to proximal migration of the spiral. Four patients complained of urgency, which was relieved by anticholinergic agents. Stone incrustation was found on 2 out of 3 spirals removed (66%), and the stone turned out to be calcium phosphate and struvite by scanning electron microscopy and infrared spectrophotometry. In 1 patient, stone formation was so abundant that it almost obstructed the lumen of the redundant tip of the spiral. From our preliminary results, the intraprostatic spiral seems to be a good alternative to an indwelling catheter for patients awaiting prostatectomy. Nevertheless, the potential complication of stone incrustation should be anticipated and it is suggested to remove the device as soon as possible or to replace it at regular intervals.
From January to July 1989, the DNA histogram of testicular open biopsies was done for 11 patients of primary infertility and 7 patients of a control group. There were 2 failures in these 36 specimens. The flow cytometric analysis revealed characteristic patterns in the relative numbers of haploid (1C), diploid (2C), and tetraploid (4C) cells. In the presence of normal spermatogenesis, the haploid compartment contained the majority of cells, followed by the diploid, and then the tetraploid (1C greater than 2C greater than 4C). The other diagnostic criteria of flow cytometry were as follows: hypospermatogenesis (2C greater than 1C greater than 4C), the maturation arrest (2C greater than 4C greater than 1C), and Sertoli-cell-only syndrome (2C, near 100%). According to the aforementioned diagnostic criteria, the results of DNA histograms were compared with the histopathology diagnosed by junior or senior pathologists. These patterns of DNA histograms correlated with the diagnoses by senior pathologists in 28 of 34 specimens (82.6%), while there were only 20 of 36 pathologic diagnoses (55.6%) which matched between junior and senior pathologists. It is shown that abundant experience is needed for testis pathologists to diagnose accurately. The DNA histograms correlate well with pathological findings, with the advantages of quantification and fewer specimens needed. In conclusion, testicular tubular cell DNA histograms appear to be a reliable modality in the evaluation of spermatogenesis. They provide the quantitative information of sperm maturation and help in making appropriate decisions in the management of male infertility.
From May 1986 to January 1989, a total of 178 patients with small prostate (less than 20 grams) received transurethral resection for benign prostatic hyperplasia. Twenty-two patients (12.4%) developed bladder neck contracture with an average interval of 247 days. The prophylactic bladder neck incision was performed concomitantly with transurethral resection of the prostate on 72 patients. Although smaller adenoma (average weight: 11.4 grams) was resected in this group, the bladder neck contracture occurred in 4 patients (5.6%), compared to 18 contractures in 106 patients (16.9%) who underwent transurethral resection of the prostate alone for larger adenoma (14 grams), P value less than 0.05. The operation time, peri-operative morbidity and hospital stay were similar in these two groups. It appeared that prophylactic bladder neck incision could protect against the formation of bladder neck contracture in patients with small obstructing prostatic adenoma.
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A 37-years-old female who was suffering from end-stage renal disease for about 6 years received allograft renal transplantation 4 years ago. She has been receiving 50mg of Cyclosporin A orally daily for immuno-suppression since then. Gross haematuria was noted and computerised tomography showed native left renal pelvic and ureteral multi-focal transitional cell carcinoma with severe hydronephrosis. Laparoscopic bilateral nephroureterectomy and bladder cuff excision were performed. In the past, history of previous operation was considered a relative contraindication for laparoscopic surgery. To our knowledge, we present the first case of laparoscopic treatment for native renal pelvic and ureteral transitional cell carcinoma after renal allograft transplantation without a hand-assisted device. This case shows the feasibility of laparoscopic bilateral nephroureterectomy in patients with transplanted kidneys.
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