Figure 1 Port and trocar position

Statistical analysis

          Demographic data were analyzed using descriptive statistics and presented as a percentage, mean and standard deviation, or median (if the distribution was not normal). Spearman's correlation was used to determine the association between factors. A p-value of <0.05 was considered statistically significant. All data analysis was carried out using STATA version 10.0 (StataCorp, College Station, TX, USA).

Results

Baseline characteristics and operative outcome

          Of 20 patients undergoing LRP, the median age was 67.5 years (57-76). The mean pre-operative prostate specific antigen (PSA) level was 14.1ng/mL (SD 10.0). Seven patients were treated with preoperative GnRH agonist due to undesirable symptoms and the long waiting time for surgery. Mean pre-operative pathological resulted from transrectal ultrasound prostate biopsy was Gleason 7 (range 6-9). Five patients underwent nerve-sparing surgery.

           The median operative time was 180 min (range 120-330) and the median estimated blood loss was 400 ml (100-2,000), respectively.  Only 2 patients received a blood transfusion. There were 3 perioperative complications; 1) one patient had to be converted to open radical prostatectomy due to hemodynamic instability in steep Trendelenburg position. 2) Urethrovesical anastomosis bleeding at postoperative day 14 that needed endoscopic intervention  to stop the bleeding. 3) Urine leakage that could be resolved spontaneously before the removal of the urethral catheter. However, there was neither serious complication nor perioperative mortality in this study. The median length of hospital stay was 5 days (range 4-10).

          Regarding the TNM pathological staging, 13 patients (65%) had a pT2 disease, 6 patients (30%) had a pT3b disease and 1 patient (5%) had d pT3a disease. Six patients (30%) had a positive margin; four out of six were pT3b. The mean final Gleason score was 7. The average prostate tissue weight was 43 grams (range 22-65) as shown in Table 1.

Association between the number of cases and clinical factors

          A Spearman's correlation was run to assess the relationship between the operative time and number of the case using a small sample of 20 participants. There was a strong negative correlation between the operative time and number of case, which was statistically significant, r=-0.672, p=0.0012 (Figure 2). The operative time was longer in the early experience cases and became shorter.

          Likewise, there was a trend toward a negative correlation between estimated blood loss and number of the case but did not reach statistical significance. As shown in Figure 3, after 5 cases, there was a plateau of estimated blood loss at just below 500 ml.

Figure 3 Correlation between blood loss and the number of case

Discussion

          Cancer of the prostate is important in male in Thailand. Radical prostatectomy is one of the curative treatments for localized prostate cancer. The 10-year specific survival rate after this operation is greater than 85% ^3,4. However, because of potential perioperative morbidity of open surgery, minimally invasive surgery by laparoscopy is an original approach designed to achieve the same oncological results as conventional radical prostatectomy while decreasing the morbidity of this operation ⁵.

          The present study reported data on perioperative parameters and morbidities. The overall results were comparable to other reported studies both in Thailand and other countries as shown in Table 2.

          The median operative time in this series was 180 min which was shorter than other reported series (208-350 min) ^6-11. The operative time was more than 250 minutes in the first five patients, but as the surgeon gained more experience, it became shorter. The rate of conversion to open surgery was less than two times compared to the report by Chaiyong et al ¹⁰. The transfusion rate of 10% in our series was comparable to the rate reported by Bollens et al. ⁹ and it was less than other reported series from Thailand (16.7-27.6%) ^10,11. The better outcome in this cohort was partly due to the major advancement in laparoscopic technology; visual guidance and surgical technique over the last decade and the better postoperative care improvement.

Early experience of LRP resulted in 9.6-36% of complications ^{9, 12}. In this series, the complication rate was 15% which was acceptable, and there was no post-operative mortality.

          From the oncological point of view, it is still too early to evaluate the long-term results from the present series. The overall positive surgical margin rate was 30% which was slightly higher compared to many series with the positive margin of 12.3%- 29.8% ^6-11. The patients' high T stage of pT3b in 30% of patients could have contributed to this higher rate of positive margin.

          This study reported the outcomes and morbidity of LRP from the first case series. The present series included the initial experience period that is needed to contribute the skills required for success. However, the complication rates were minor complications and no mortality in the present series. This indicated that the author technique and experience for LRP can be a standard method for prostate cancer surgery in Srinagarind hospital.

Conclusion

          Perioperative outcomes of LRP in the first 20 cases were satisfactory, based on the experience of the surgeon. The morbidity was acceptable. This operation was safe and feasible in Srinagarind hospital.

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