Biomedical subjects

Naoki Oguchi

Publications and source records attributed to Naoki Oguchi.

4 recordsLinked to original sources

PubMed2004

Retroperitoneoscopic partial nephrectomy with transient occlusion of renal artery for treatment of small renal tumors.

OBJECTIVES: To evaluate the results of retroperitoneoscopic partial nephrectomy with transient occlusion of the renal artery for treatment of patients with small renal tumors. METHODS: From May 2002 to March 2003, 12 consecutive patients with T1N0M0 renal tumors with a median diameter of 3.0 cm underwent retroperitoneoscopic partial nephrectomy. The renal artery was clamped transiently without occlusion of the renal vein and the tumor was excised with scissors. Intracorporeal renal cooling was achieved by cold saline perfusion of the renal pelvis through a single-J ureteral catheter. Hemostasis was achieved by approximating the renal parenchyma over the perirenal fatty tissue using a retroperitoneoscopic suturing technique. RESULTS: Of the 12 patients, 11 successfully underwent partial nephrectomy retroperitoneoscopically. The median operative time, renal ischemic time, and amount of blood loss in the successful procedures was 220 minutes (range 132 to 340), 50 minutes (range 16 to 115), and 150 mL (range 50 to 800), respectively. The renal calix was opened and repaired in 10 patients. The surgical margin was negative in all patients. The postoperative course was uneventful in all patients, and the return to work was achieved in a median of 18 days (range 9 to 39). The renal function of the affected kidney was well preserved postoperatively, when examined by renal scintigraphy. Neither local recurrence nor distant metastasis was found during the median follow-up period of 10 months (range 1 to 18). CONCLUSIONS: Retroperitoneoscopic partial nephrectomy with transient occlusion of the renal artery is a useful and less-invasive method for resection of small renal tumors. Additional technologic developments to reduce ischemic times and to cool the kidneys laparoscopically are required.

Aged↗

PubMed2002

Retroperitoneoscopic partial nephrectomy using microwave coagulation for small renal tumors.

OBJECTIVES: The outcome of laparoscopic partial nephrectomy using a microwave tissue coagulator for treatment of small renal tumors was studied. PATIENTS AND METHODS: From June 1999 to May 2001, eight patients with small renal tumors of less than 5.0cm in diameter (1.0-5.0cm, T1N0M0) underwent retroperitoneoscopic partial nephrectomy. To control bleeding during the partial nephrectomy, the renal parenchyma around the tumor was coagulated using a microwave tissue coagulator with a needle of 1.5cm length. The tumor was circumscribed within the coagulated area with 8-13 punctures of the coagulation needle, and partial nephrectomy was performed using scissors and bipolar forceps. RESULTS: All eight patients successfully underwent the procedure retroperitoneoscopically. The average operative time was 295 minutes and the average blood loss was 129ml. Three patients showed urine leakage from the renal calyces, which was controlled by suturing retroperitoneoscopically. In two patients, the surgical margin was revealed to be positive for renal cell carcinoma by frozen section pathology and additional resection was performed in these individuals. The patients were discharged from the hospital with almost full convalescence on day 10 on average. Within the mean follow-up period of 10.4 months, no recurrence was found when examined with computer tomography (CT) using contrast media. As a complication, one patient experienced a decrease in function of the operated kidney caused by unknown reason. CONCLUSION: Retroperitoneal partial nephrectomy using a microwave tissue coagulator is useful for treatment of small renal tumors located at the peripheral area of the kidney. Bleeding from the renal parenchymal incision site is well controlled without occlusion of the renal artery with additional use of a bipolar coagulator, when necessary. Further experience and long-term follow-up are mandatory however, to establish the usefulness of this technique.

Adult↗

PubMed2002

[A clinical analysis of patients with early-stage prostate cancer managed without initial treatment].

To search for a more suitable qualification indicating watchful waiting, we performed a retrospective study against early-stage prostate cancer patients managed without initial treatment. Thirty-three patients who had not been treated for more than 6 months after diagnosed as T1c or T2 prostate cancer were studied. The median values of total observation period, age at diagnosis, and initial PSA were 27.0 months, 69.0 years old, and 7.0 ng/ml, respectively. Among 28 patients who had had measurement of serum PSA at least three times, seven patients showed a significant PSA elevation when transition of PSA level was analyzed using linear regression analysis. The other patients had been stable or PSA level declined. Between these two groups, there was no significant difference regarding age, initial PSA, PSA density, Gleason score, number of cancer-positive core, and cancer-occupying rate in biopsy specimen. The median PSA doubling time in patients showing PSA elevation was 36.3 months. There were no patients showing PSA elevation among those with a cancer-occupying rate of less than 5%. Clinical disease progression was obviously observed in two cases although one did not show PSA elevation. During the observation period, treatment was eventually started in seven patients. The 5-year rate of no treatment was 53.8%. Although a significant independent factor predicting the future treatment was not identified, univariate analysis revealed that the initial PSA value in patients undergoing treatment was significantly higher than that of those without treatment (p = 0.032). We concluded that early-stage prostate cancer has clinical variability, and regular clinical evaluations as digital rectal examination should be performed when the patient was managed with watchful waiting.

Aged↗

PubMed2002

[The experience of laparoscopic radical nephrectomy for renal tumors].

We evaluate the safety and feasibility of laparoscopic radical nephrectomy for renal tumors. Between September 1993 and October 2001, 18 patients with renal tumors underwent laparoscopic radical nephrectomy. The mean patient age was 57.1 years ranging from 36 to 78. Clinical stage was T1N0 in all patients. The mean tumor diameter was 4.0 cm ranging from 1.8 to 7.0. Laparoscopic radical nephrectomy was performed by using the transperitoneal anterior approach on 11 patients and retroperitoneal approach on 7 patients. The specimen was removed through an extended stab wound after blunt segmentation of renal parenchyma in a specimen bag (LapSac). The mean operative time was 405 (270-550) and 453 (325-635) min for the transperitoneal approach and retroperitoneal approach respectively, and the mean blood loss was 281 (52-700) and 223 (10-850) ml, respectively. There was an intraoperative complication of minor splenic injury in 2 patients receiving the transperitoneal approach, which was conservatively managed. Histopathology revealed renal cell carcinoma in 17 patients and renal oncocytoma in one patient. There was no recurrence with a mean follow-up of 28.9 months. Compared with 13 patients who underwent open radical nephrectomy during the same period, laparoscopic nephrectomy has a longer operative time (424 versus 214 min, p < 0.001), equal blood loss (259 versus 210 ml, p = 0.59), quicker resumption of ambulation (1.8 versus 2.5 days, p = 0.016) and food intake (1.4 versus 2.2 days, p = 0.003), shorter postoperative hospital stay (10.9 versus 18 days, p = 0.0016), and a tendency of less frequent analgesic requirements (1.9 versus 4.7 times, p = 0.09). Laparoscopic radical nephrectomy is a safe and useful surgery for renal tumors providing minimal invasiveness.

Adult↗