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Biomedical subjects

K R Han

Publications and source records attributed to K R Han.

10 recordsLinked to original sources
PubMed2006

Metachronous colorectal cancer.

OBJECTIVE: Although the diagnosis of metachronous colorectal cancer have increased, due primarily to improvements in diagnostic modalities, the potential risk factors for these tumours are not well known. We compared the characteristics of patients with metachronous and sporadic primary colorectal cancer to determine risk factors for its occurrence. PATIENTS AND METHODS: We reviewed the records of 5447 patients with colorectal cancer, who had been treated at Asan Medical Centre between July 1989 and January 2004. A metachronous cancer was defined as a secondary colorectal cancer occurring more than 6 months after the index cancer. RESULTS: Metachronous colorectal cancer occurred in 39 (0.7%) patients. Their average age was 53 years, somewhat younger than the average age of sporadic colorectal cancer patients (58 years). In patients with metachronous cancer, the cancer was more likely to be located in the right colon (P < 0.03), and the incidence of synchronous polyps or cancer was significantly higher (P < 0.001). The relative distributions of histological grades and clinicopathological characteristics were similar in index and metachronous cancers. Metachronous cancers were diagnosed more frequently at an early stage. The time interval between index and metachronous cancer ranged from 6 to 215 months (mean 39 months), with 13 (33.3%) patients diagnosed with metachronous cancer after 5 years. CONCLUSION: We found that in patients aged < 50 years, existence of synchronous polyps or cancer influence on the development of metachronous colorectal cancer. Regular follow-up is necessary for early detection, even after 5 years, for these patients.

Adult↗
PubMed2005

Extrapedicular approach of percutaneous vertebroplasty in the treatment of upper and mid-thoracic vertebral compression fracture.

PURPOSE: To evaluate the clinical outcome of the extrapedicular approach of percutaneous vertebroplasty (PVP) for upper and mid-thoracic vertebral compression fractures in patients. MATERIAL AND METHODS: Extrapedicular vertebroplasty was performed in painful compression fractures at T4-T8 levels. The assessment criteria were changes over time in visual analog scale (VAS) and mobility score. We evaluated the volume of cement injected, the size of needle required, and complications. RESULTS: Procedures were performed in 27 patients with a total of 34 affected vertebral bodies. Early (within a week) and one year later, clinical follow-ups showed that pain intensity had decreased by 50% one day after operation and later by 70-80%. Mobility scores of all patients were improved immediately after the procedure. Average volume of polymethylmethacrylate (PMMA) per vertebral body was 3.8 +/- 1.2 ml. Leakage of PMMA occurred in one vertebral level (intradiskal space), but did not cause clinical complications. CONCLUSION: PVP of upper and mid-thoracic spine with an extrapedicular approach is an efficient and safe procedure for treating painful thoracic vertebral compression fracture under a cautious patient selection and meticulous technical procedure.

Aged↗
PubMed2002

Risperidone-induced priapism.

Priapism is well documented as a potential side effect of psychotropic medications. To date, there have been no reports of risperidone-induced priapism in the urologic literature. We report a case of risperidone-induced priapism requiring surgical treatment.

Antipsychotic Agents↗
PubMed2001

Prognostic factors and molecular markers for renal cell carcinoma.

Renal cell carcinoma is the most common cancer in the kidney, affecting nearly 30,000 Americans every year and is associated with over 12,000 deaths annually. If detected early, renal cell carcinomas can be cured surgically. However, once metastatic disease develops the prognosis for long-term survival is poor. Unfortunately, one-third of patients have metastatic disease at the time of diagnosis and approximately 50% of the patients undergoing surgical resection for less advanced disease eventually relapse. This review examines the clinical and molecular prognostic tools currently available or under investigation for kidney cancer.

Biomarkers, Tumor↗
PubMed2000

Ureteroenteric anastomosis in continent urinary diversion: long-term results and complications of direct versus nonrefluxing techniques.

PURPOSE: Controversy exists over the importance of antireflux mechanisms in large volume, low pressure intestinal bladder substitutions. Despite the theoretical benefits of reflux prevention, antirefluxing ureteral reimplantations may have a greater risk of anastomotic stricture. We hypothesize that this inherent stricture rate may outweigh the potential benefits associated with reflux prevention. To assess this question critically we compare our results to those of direct and nonrefluxing techniques of ureterointestinal anastomosis during continent diversion. MATERIALS AND METHODS: Between 1990 and 1998, 58 patients underwent continent urinary diversion using an Indiana pouch or ileal orthotopic neobladder following cystectomy for muscle invasive bladder cancer. A total of 56 renal units were implanted using an end-to-side Nesbit direct anastomosis and 60 were implanted in a nonrefluxing manner. Clinical end points included anastomotic stricture formation, hydronephrosis, pyelonephritis, upper tract stone formation and renal deterioration, and were assessed with a mean followup of 41 months. RESULTS: Of 60 nonrefluxing ureteroenteric anastomoses 8 (13%) resulted in nonneoplastic stricture formation compared to 1 of 56 (1.7%) direct anastomoses, which was statistically significant (Fisher's exact test p <0.05). Strictures occurred up to 6 years following the original surgery. There was no significant difference between the 2 groups in regard to hydronephrosis, pyelonephritis, upper tract stone formation or azotemia. CONCLUSIONS: Nonrefluxing methods of ureterointestinal reimplantation resulted in a statistically significant higher rate of anastomotic stricture than the end-to-side direct anastomosis. This finding appears to outweigh any theoretical benefits of preventing pyelonephritis, stones or azotemia. For patients undergoing large volume, low pressure continent diversion the refluxing ureterointestinal anastomosis may be the technique of choice since it preserves renal function as well as the nonrefluxing method, is technically easier to perform and poses less risk of stricture. Delayed stricture formation years after surgery underscores the necessity for long-term radiological followup in patients following continent diversion.

Adult↗
PubMed2000

Lymphatic mapping and intraoperative lymphoscintigraphy for identifying the sentinel node in penile tumors.

Lymph node mapping has become an integral part of the management of melanoma and breast cancer with regard to both staging and treatment. We report our technique for lymphatic mapping and intraoperative lymphoscintigraphy applied to a patient with penile melanoma. This technique may improve the sensitivity of identifying the sentinel lymph node in patients with malignant penile lesions.

Aged↗
PubMed1999

Prospective evaluation of endorectal magnetic resonance imaging to detect tumor foci in men with prior negative prostastic biopsy: a pilot study.

PURPOSE: Prostate cancer foci have a characteristic appearance on endorectal magnetic resonance imaging (MRI) which might be useful for prostate cancer detection. In this pilot study the ability of endorectal MRI to detect prostate cancer foci prospectively in men at risk for a malignant prostatic neoplasm is assessed. MATERIALS AND METHODS: Endorectal MRI was performed in 33 consecutive men with 1 or more prior negative prostatic biopsies. All studies were read by 2 MRI dedicated study radiologists in consensus before and after receiving patient clinical data. Areas of interest on endorectal MRI were mapped as low, moderate or high suspicion for carcinoma on a prostate model. Directed needle biopsy cores of the prostate were obtained based on this model, and the histopathological findings were compared with MRI results. RESULTS: Carcinoma was detected in 7 of 33 men (21.2%) on post-MRI biopsy, including 1 of 18 (5.6%) with low, 1 of 8 (12.5%) with moderate and 5 of 7 (71.4%) with high suspicion MRI. The site of positive biopsy correlated correctly with the area of suspicion on MRI in 85.7% of cases. Overall, endorectal MRI had 40% positive predictive value (moderate or high suspicion), 94.4% negative predictive value (low suspicion) and 69.7% accuracy. On multivariate analysis positive endorectal MRI was associated with an 11.3-fold risk of positive biopsy. CONCLUSIONS: Endorectal MRI may effectively stratify patients with prior negative prostatic biopsy into low, moderate and high risk groups for a malignant prostatic neoplasm, and may improve our ability to identify prostatic tumor foci prospectively.

Aged↗
PubMed1999

Endovascular stent graft for management of ureteroarterial fistula after orthotopic bladder substitution.

We describe the first case of an ureteroarterial fistula developing after orthotopic neobladder substitution and its minimally invasive management using endovascular stent grafting. We outline the risk factors for the development of ureteroarterial fistulae and trace the evolution of diagnostic and therapeutic modalities used in the management of these life-threatening complications. Minimally invasive management with endovascular stent grafting and exclusion of two pseudoaneurysms in the iliac artery system was performed successfully. After successful endovascular exclusion of two pseudoaneurysms, the patient's hematuria resolved and he recovered fully. Three-dimensional computed tomography performed 3 months later documented a patent aortoiliac arterial system without evidence of pseudoaneurysm or endovascular leak. Ureteroarterial fistula after orthotopic bladder substitution was managed with an endovascular stent graft without the need for extra-anatomical vascular bypass. Early recognition, stabilization, and angiographic evaluation followed by this minimally invasive technique may avoid open operative repair and attendant morbidity.

Cystectomy↗