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Koon H Rha

Publications and source records attributed to Koon H Rha.

15 recordsLinked to original sources
PubMed2005

Laparoscopic pyeloplasty: current status.

OBJECTIVE: To review current publications and report our results and long-term follow-up of laparoscopic transperitoneal pyeloplasty for pelvi-ureteric junction (PUJ) obstruction. PATIENTS AND METHODS: In all, 147 laparoscopic transperitoneal pyeloplasties were performed between August 1993 and November 2000 (mean patient age 35.7 years, range 10-85). All patients were diagnosed with PUJ obstruction by symptoms and intravenous urography, radionuclide diuretic renography or ultrasonography. An Anderson-Hynes dismembered pyeloplasty (106), Y-V plasty (28), Fenger plasty (11) and others (two) were used, according to the intraoperative findings. Twenty-five patients had secondary obstruction, having had previous surgery to the PUJ. The mean (range) follow-up was 24 (3-84) months; all patients were followed clinically and radiologically. RESULTS: The mean operative duration time was 246 (100-480) min and estimated blood loss was 158 mL. Crossing vessels were identified in 80 cases. The success rate for all, primary and secondary patients was 95%, 98% and 84%, respectively. With one exception, all failures occurred within 6 months. Twenty-one patients (22 renal units) had simultaneous laparoscopic pyeloplasty and lithotomy; they were treated successfully and all have an intact PUJ, and 20 renal units (90%) were stone-free. The overall complication rate was 8.8%. CONCLUSIONS: This series has comparable success rates to those of open pyeloplasty and the morbidity was minimal. Laparoscopic pyeloplasty may soon become the standard operation for PUJ obstruction, especially with crossing vessels.

Adolescent↗
PubMed2004

Favorable outcomes among recipients of living-donor nephrectomy using video-assisted minilaparotomy.

BACKGROUND: Minimally invasive, living-donor nephrectomy (LDN) is an attractive procedure for the donor in kidney transplantation (KTx). Its advantages include better cosmesis, shorter hospital stay, and rapid recovery. The most commonly performed, minimally invasive nephrectomy is done laparoscopically. However, the technical challenges, a steep learning curve for the surgeon, the risk of impaired early graft function, and the high cost of the procedure, have prevented minimally invasive LDN from gaining wide acceptance. To overcome these problems, we have developed a new surgical procedure named video-assisted minilaparotomy (VAM) for LDN. VAM-LDN is performed entirely with a small retrieval incision. Moreover, it does not require the induction of pneumoperitoneum, thereby avoiding potential vascular and renal complications. METHODS: We evaluated the outcome of transplant recipients receiving kidneys with the VAM-LDN procedure by retrospectively comparing the surgical outcomes of patients who underwent KTx with the conventional open nephrectomy (group I, n=82) and VAM-LDN (group II, n=70) procedures from March 1, 1997, to June 30, 2002, at our institution. We compared postoperative complications, patient and graft survival, and graft functions between these two groups during a 12-month follow-up period. RESULTS: There were no differences in demographic data, ABO compatibility, degree of human leukocyte antigen matching, or method of immunosuppression between the two groups (P >0.05). No significant difference was observed in complications such as delayed graft function, acute rejection, ureter complication, graft failure, or patient's mortality. There was no difference in graft function between the two groups, as determined by serum creatinine level measured during the 12-month follow-up. CONCLUSION: The short-term recipient outcome was favorable in patients who underwent KTx with the VAM-LDN procedure.

Adult↗
PubMed2004

Complications of abdominal urologic laparoscopy: longitudinal five-year analysis.

OBJECTIVES: To analyze complications of abdominal laparoscopic surgery of the urinary tract at a single institution during a 5-year period. METHODS: From 1996 to 2000, we identified 894 abdominal laparoscopic procedures performed at a single institution: 600 nephrectomies (live donor, simple, radical, nephroureterectomy, and partial), 112 pyeloplasties, 61 renal biopsies, 35 retroperitoneal lymph node dissections, 31 renal cyst ablations, 18 adrenalectomies, and 37 other abdominal procedures. The charts were retrospectively reviewed for complications, which were classified as operative, postoperative, or medical. Complications were correlated with patient age and American Society of Anesthesiologists score. Statistical analysis was performed with Fisher's exact test and chi-square tests. RESULTS: A total of 118 complications (13.2%) occurred. Two patients (0.2%) died. As a result of operative complications, the procedure of 13 patients (1.5%) was converted to an open one. As a result of postoperative complications, 13 (1.5%) underwent operative and 6 (0.7%) nonoperative intervention. The most common intraoperative complications were vascular (n = 23), adjacent organ (n = 10), and bowel (n = 9) injuries. The most common postoperative complications were neuromuscular pain (n = 12), hematoma (n = 11), urine leak (n = 7), and wound infection (n = 7). The differences in the annual complication rates for all procedures did not attain statistical significance (P = 0.5). Among all procedures, excluding live donor nephrectomy, complications of any kind correlated with a greater patient American Society of Anesthesiologists score (P = 0.01). CONCLUSIONS: Rather than decreasing, the overall incidence of laparoscopic complications did not change significantly during a 5-year period at our institution. The factors contributing to this observation likely included the progression of inexperienced individual surgeons through the learning curve, the introduction of new, more sophisticated laparoscopic procedures, and stable rates of patient comorbidity. This experience may represent the average complication rate for urologic laparoscopy at a large-volume, academic training center.

Adrenalectomy↗
PubMed2004

Laparoscopic-assisted renal autotransplantation.

OBJECTIVES: To report our experience with laparoscopic nephrectomy and autotransplantation for the management of a variety of conditions with significant loss of healthy ureteral tissue or ureteral length. Renal autotransplantation has been described as an effective method for addressing this problem, avoiding the need for nephrectomy or complex ureteral replacement. In an effort to decrease the morbidity associated with traditional autotransplantation we elected to perform laparoscopic procurement of the kidney. METHODS: Four patients underwent laparoscopic nephrectomy using a transperitoneal four-port technique and subsequent autotransplantation into the iliac fossa for the treatment of proximal ureteral avulsion (2 patients), ureteral malignancy, and ureteral stricture. All patients had less than 5 cm of viable ureter. RESULTS: All procedures were performed without intraoperative complications. All renal scans on postoperative day 1 demonstrated good perfusion. None of the patients had a postoperative rise in serum creatinine. On postoperative day 1, the mean creatinine value was 0.95 mg/dL. Three patients had an uneventful postoperative course. One patient, however, had loss of the graft because of renal vein thrombosis on postoperative day 7. She was later found to have an undiagnosed thrombophilic disorder (decreased levels of antithrombin III) and to have a recent history of oral contraceptive use. CONCLUSIONS: Laparoscopic nephrectomy with renal autotransplantation is a feasible minimally invasive alternative to treat patients who have significant ureteral loss. This approach avoids the need for an upper abdominal or flank incision, resulting in decreased morbidity. The initial follow-up studies indicated stable renal function. Additional long-term observation is currently under way.

Adult↗
PubMed2004

Urethral stricture after pancreas-kidney transplantation due to polypoid urethritis.

Urologic complications are common after pancreas-kidney transplantation using bladder drainage. We report a case of urethral stricture caused by polypoid urethritis occurring 4 years after simultaneous pancreas-kidney transplantation. Endoscopic exploration revealed irregular, ragged-appearing urethral mucosa. The diagnosis of polypoid urethritis was confirmed histopathologically.

Adult↗
PubMed2004

Tumor capacitance: electrical measurements of renal neoplasia.

PURPOSE: Studies have demonstrated that biological tissues possess unique electrical properties. We evaluate the electrical properties of renal tumors using a specialized probe with the capability of measuring intra-tissue capacitance in an ex vivo model of fresh surgically excised tissue. MATERIALS AND METHODS: An electrical monitoring device was used to measure tissue capacitance at a frequency of 1 MHz on 34 ex vivo kidney specimens freshly obtained after surgical excision. Tissue capacitance was promptly measured in the excised tumor as well as surrounding normal parenchyma and fat. Dielectric permittivity in each tissue was calculated using the measured capacitance data. These data were compared and correlated to pathological findings. RESULTS: The final pathology on the 34 specimens revealed 28 renal cell carcinomas (RCC), 3 oncocytomas and 3 angiomyolipomas. In patients with RCC dielectric permittivity of tumor tissue was 1.43 +/- 0.39 times greater than that of surrounding normal parenchyma (p < 0.001). The average tumor-to-normal tissue dielectric permittivity ratio for RCC was significantly greater than that for angiomyolipoma (1.43 +/- 0.39 vs 0.73 +/- 0.77, p < 0.05) but similar to that for oncocytoma (1.43 +/- 0.39 vs 1.63 +/- 0.77, p = 0.39). CONCLUSIONS: Tissue capacitance measurements may be used to differentiate renal tumor from surrounding normal tissue. In vivo studies will ultimately determine the clinical use of this technology in localizing renal neoplasms and differentiating between malignant and benign tissues.

Adenoma, Oxyphilic↗
PubMed2004

Laparoscopic partial nephrectomy: effect of warm ischemia on serum creatinine.

PURPOSE: Laparoscopic partial nephrectomy (LPN) has been shown to be a safe and effective option for small renal tumors. However, limited data are available regarding the effect of warm ischemic time on postoperative renal function. We assessed the effect of variable durations of warm ischemia on long-term renal function in patients undergoing LPN. MATERIALS AND METHODS: A total of 118 patients with a single, unilateral, sporadic renal tumor and normal contralateral kidney underwent LPN from August 1998 to November 2002. Patients were divided into 3 groups based on warm ischemic time, namely group 1-no renal occlusion in 42, group 2-warm ischemia less than 30 minutes in 48 and group 3-warm ischemia greater than 30 minutes in 28. All 3 groups were assessed for changes in serum creatinine 6 months after LPN. Additionally, renal remnants were examined with cross-sectional imaging. RESULTS: At a median followup of 28 months (range 6 to 56) median creatinine had not statistically increased postoperatively. None of the 118 patients progressed to renal insufficiency or required dialysis after LPN. CONCLUSIONS: Based on postoperative serum creatinine warm ischemia time up to 55 minutes does not significantly influence long-term renal function after LPN. Thus, during LPN efforts to minimize warm ischemia are important but they should not jeopardize cancer control, hemostasis or collecting system closure.

Adult↗
PubMed2003

Optimization of the Erbium:YAG laser for precise incision of ureteral and urethral tissues: in vitro and in vivo results.

BACKGROUND AND OBJECTIVES: Tissue damage during endoscopic treatment of urethral and ureteral strictures may result in stricture recurrence. The Erbium:YAG laser ablates soft tissues with minimal peripheral damage and may be a promising alternative to cold knife and Holmium:YAG laser for precise incision of urological strictures. STUDY DESIGN/MATERIALS AND METHODS: Optimization of the Er:YAG laser was conducted using ex vivo porcine ureteral and canine urethral tissues. Preliminary in vivo studies were also performed in a laparoscopic porcine ureteral model with exposed ureter. Laser radiation with a wavelength of 2.94 microm, pulse lengths of 8, 70, and 220 microseconds, output energies of 2-35 mJ, fluences of 1-25 J/cm2, and pulse repetition rates of 5-30 Hz, was delivered through 250-microm and 425-microm core germanium oxide optical fibers in direct contact with tissue. RESULTS: Ex vivo perforation thresholds measured 2-4 J/cm2, with ablation rates of 50 microm/pulse at fluences of 6-11 J/cm2. In vivo perforation thresholds were approximately 1.8 J/cm2, with the ureter perforated in less than 20 pulses at fluences greater than 3.6 J/cm2. Peripheral thermal damage in tissue decreased from 30 to 60 microm to 10-20 microm as the laser pulse length decreased from 220 to 8 microseconds. Mechanical tissue damage was observed at the 8 microseconds pulse duration. CONCLUSIONS: The Er:YAG laser, operating at a pulse duration of approximately 70 microseconds, a fluence greater than approximately 4 J/cm2, and a repetition rate less than 20 Hz, is capable of rapidly incising urethral and ureteral tissues with minimal thermal and mechanical side-effects.

Animals↗
PubMed2003

Management of obliterated urinary segments using a laser fiber for access.

PURPOSE: We describe a modification of the cut to the light and core-through procedures using a laser fiber to gain through and through access for treatment of complete occlusion of the ureter or urethra. MATERIALS AND METHODS: Three patients presented with complete obliteration of the ureter (2) and vesicourethral anastomosis (1). In each case the laser fiber was advanced through the obliterated segment under direct vision and then exchanged for a standard guide wire using an open ended catheter. RESULTS: Through and through access was obtained in all 3 cases and allowed subsequent incision for repair. In all 3 patients the area of incision was stented and urinary continuity was restored. CONCLUSIONS: Loss of access can lead to complications and termination of any endoscopic procedure. Use of the laser fiber to incise through the obliterated segment and subsequently act as a guide wire in our experience minimized the possibility for loss of access. The disadvantage is the cost of the laser fiber, which cannot be reused. Use of a laser fiber as a guide wire can be a viable and effective option for gaining access across strictures when alternative methods fail.

Aged↗
PubMed2003

Optical access trocar injuries in urological laparoscopic surgery.

PURPOSE: Inadvertent injuries during trocar and Veress needle placement are a rare but potentially serious complication of laparoscopic surgery. An access alternative is an optical trocar under direct vision. Limited data are available regarding the safety of this technique. We reviewed complications related to optical access trocars during standard transperitoneal urological laparoscopic procedures performed at a single institution. MATERIALS AND METHODS: From 1995 to 2001 the optical access trocar was used as the initial trocar in 1,283 urological laparoscopic procedures. The procedures included simple and radical nephrectomy in 309 cases, donor nephrectomy in 386, partial nephrectomy in 79, pyeloplasty in 173 and various other procedures in 336. Intra-abdominal complications caused by optical access trocar were assessed. RESULTS: The optical trocar was inserted at the umbilicus in 88 patients (7.4%), in the right upper quadrant in 445 (34.7%) and in the left upper quadrant in 750 (58.5%). There were 4 injuries (0.31%) associated with the optical access trocar. Complications occurred on the left side in 3 cases and on the right side in 1, including 1 injury to bowel, 1 mesenteric injury resulting in a retroperitoneal hematoma and 2 injuries to epigastric vessels. Three cases were recognized and repaired immediately but in a case of epigastric vessel injury the expanding abdominal wall hematoma required postoperative repair. CONCLUSIONS: Optical access trocars provide a safe and rapid technique for initial trocar placement. Results of this large series support the finding that few trocar related complications are associated with the optical access trocar.

Adolescent↗
PubMed2003

Laparoscopic radical versus partial nephrectomy: assessment of complications.

PURPOSE: We evaluated the short-term morbidity and complications of laparoscopic radical nephrectomy (LRN) compared with laparoscopic partial nephrectomy (LPN). MATERIALS AND METHODS: From May 1998 to May 2002, 114 patients were identified with a single unilateral sporadic renal tumor and a normal contralateral kidney. These individuals had undergone LRN (35) or LPN (79). RESULTS: The LRN and LPN groups were analyzed for age, sex, American Society of Anesthesiologists score and body mass index. Mean tumor size in patients undergoing LRN and LPN was 2.8 +/- 1.2 (range 0.9 to 4.5) and 2.5 +/- 1.0 cm (range 1 to 4.5), respectively (p = 0.17). There were no differences between the 2 groups in terms of mean hospital stay, blood transfusion or surgical complications. There was no difference in mean preoperative and postoperative serum creatinine in patients in the LPN group. Mean postoperative serum creatinine was significantly higher than the mean preoperative level in patients in the LRN group (1.51 +/- 0.22 vs 1.18 +/- 0.37 mg/ml, range 0.6 to 2.4, p = 0.02). In each group 1 case was converted to open surgery due to bleeding. CONCLUSIONS: LPN is associated with similar postoperative convalescence and complications compared with LRN. The increase in serum creatinine noted in patients undergoing radical extirpation supports the use of LPN when clinically indicated.

Adult↗
PubMed2003

Laparoscopic nephrectomy: assessment of morcellation versus intact specimen extraction on postoperative status.

PURPOSE: We compared pathological evaluation and postoperative recovery in patients undergoing transperitoneal laparoscopic nephrectomy at our institution with morcellated vs intact specimen extraction. MATERIALS AND METHODS: A prospective evaluation of 57 consecutive patients undergoing radical and simple transperitoneal laparoscopic nephrectomy was reviewed. One patient was excluded from study due to transitional cell carcinoma, which was detected intraoperatively. The 33 morcellated specimens were extracted at the umbilical port and the 23 intact specimens were extracted through a midline infraumbilical incision. Data were obtained on narcotic requirements, hospital stay, complications, estimated blood loss, mass size based on preoperative imaging, specimen weight and extraction incision length. RESULTS: Mean incision length in the morcellated and intact specimen removal groups was 1.2 and 7.1 cm, respectively (p <0.001). No significant differences in pain or recovery were noted between the 2 groups. Two cases of microscopic invasion of the perinephric adipose tissue in the intact specimen group were up staged from clinical T1 to pT3a disease. No change in patient treatment was made based on this information. CONCLUSIONS: We did not find a significant difference in surgical time, pain or hospital stay. Only incision length was statistically significant. Postoperative recovery appeared to be similar in these 2 groups. With modern imaging modalities information on pathological stage did not alter patient treatment.

Adolescent↗
PubMed2003

Laparoscopic renal surgery after spontaneous retroperitoneal hemorrhage.

PURPOSE: We assessed the role of laparoscopic management in patients following spontaneous retroperitoneal hemorrhage from a renal tumor. MATERIALS AND METHODS: A retrospective chart review revealed 4 patients with spontaneous retroperitoneal hemorrhage treated at our institution in the last 2 years. After conservative management elsewhere patients were referred for definitive therapy. Patient characteristics and tumor size were examined and correlated with ease of surgical dissection and surgical outcome. No patient had any history of trauma. Computerized tomography was used to identify the initial extent of hemorrhage in all patients. RESULTS: All patients underwent successful laparoscopic exploration without the need for open conversion. Three patients underwent radical nephrectomy and 1 underwent laparoscopic partial nephrectomy. Renal hemorrhage extending outside of the renal capsule was associated with significantly more adhesions than renal hemorrhage confined to the renal capsule. Mean patient age was 56 years (range 36 to 70). Mean retroperitoneal tumor size was 5.3 cm (range 2.5 to 10). Three renal hematomas were extracapsular and 1 was subcapsular. Mean operative time was 182.3 minutes (range 59 to 235). Average estimated blood loss was 800 cc (range 150 to 2,100). CONCLUSIONS: Nontraumatic retroperitoneal hemorrhage of renal origin may be managed using traditional laparoscopic techniques with results similar to those achieved with open renal exploration. These cases may prove technically challenging due to fibrosis and associated tissue plane loss.

Adult↗
PubMed2003

Kidney transplantation in Yonsei University from 1979-2003.

1. Long-term graft survival has been markedly improved after the introduction of CsA microemulsion and FK-506 as our main immunosuppressants, and the use of triple maintenance immunosuppression including MMF in living-donor kidney transplantation (KTX) at Younsei University. 2. The risk factors affecting long-term graft survival in living-donor KTX were recipient and donor age, type of immunosuppression including regimen, presence of pretransplant diabetes or hepatitis B, and the development of acute rejection after KTX. 3. The long-term graft survival rate with living-unrelated donor KTX was comparable to that with HLA-haploidentical living-related donor KTX. 4. Because of the striking disparity between organ donation and the increasing demand for KTX, distant relatives, living unrelated donors (including swap donors) should be considered as an alternative approach to increasing the number of available donors when accompanied by a careful evaluation process. 5. We recommend the use of minimally invasive approaches to donor nephrectomy to increase the rate of living donor donation. 6. We recommend negative lymphocyte crossmatch conversion protocols for patients with a positive crossmatch against their potential living donor.

Adult↗