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ORIGINAL ARTICLE
Year : 2016  |  Volume : 12  |  Issue : 2  |  Page : 805-810

Retroperitoneoscopic versus open surgical radical nephrectomy for 152 Chinese patients with large renal cell carcinoma in clinical stage cT2 or cT3a: A long-term retrospective comparison


Department of Urology, Beijing Chao-Yang Hospital, Capital Medical University, Beijing 100020, China

Date of Web Publication25-Jul-2016

Correspondence Address:
Xiaodong Zhang
Department of Urology, Beijing Chao.-Yang Hospital, Capital Medical University, Beijing 100020
China
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0973-1482.186693

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 > Abstract 


Introduction: To evaluate the feasibility, safety, and long-term efficacy of retroperitoneal laparoscopic radical nephrectomy for Chinese patients with a mean body mass index (BMI) of ≤24 and large renal cell carcinoma (RCC).
Materials and Methods: A long-term retrospective analysis of clinical data of 152 Chinese patients with a mean BMI of ≤24 and large RCC. Totally, 84 patients who underwent retroperitoneal laparoscopic radical nephrectomy (RPNx) for tumor size >7 cm (group 1) were compared with 68 patients, who underwent open radical nephrectomy (group 2) for tumor with similar size characteristics. Moreover, their 10 years outcomes (or the number of patients) were divided into segments (e.g., the first 5 and last 5 years, the first 30 and last 30 patients, etc.) looking for the differences of learning curve.
Results: RPNx patients experienced significantly shorter hospital stay, less blood loss, and had a decreased analgesic requirement and more rapid convalescence. The incidence of intra- and post-operative complications was 6% and 13%, 7.2% and 16.1% in the two groups, respectively. The 5-year survival rates of the two groups were 86% and 82%, respectively.
Conclusion: Retroperitoneal laparoscopic radical nephrectomy for patients with a mean BMI of ≤24 and large RCC is safe, feasible, and the efficacious procedure produced good long-term results.

Keywords: Extraperitoneal, learning curve, nephrectomy, renal cell carcinoma, retroperitoneoscopy


How to cite this article:
Zhu X, Yang X, Hu X, Zhang X. Retroperitoneoscopic versus open surgical radical nephrectomy for 152 Chinese patients with large renal cell carcinoma in clinical stage cT2 or cT3a: A long-term retrospective comparison. J Can Res Ther 2016;12:805-10

How to cite this URL:
Zhu X, Yang X, Hu X, Zhang X. Retroperitoneoscopic versus open surgical radical nephrectomy for 152 Chinese patients with large renal cell carcinoma in clinical stage cT2 or cT3a: A long-term retrospective comparison. J Can Res Ther [serial online] 2016 [cited 2019 Dec 5];12:805-10. Available from: http://www.cancerjournal.net/text.asp?2016/12/2/805/186693




 > Introduction Top


Renal cell carcinoma (RCC) is one of the common malignancies of the urinary tract, and the incidence and mortality of RCC appears to be rising in the United States, with approximately 65,000 new cases of RCC diagnosed every year.[1],[2] The radical surgical resection methods can be generally divided into open surgery and minimally invasive surgery, and the latter includes laparoscopy and robotic endoscopy. Since Clayman et al. performed the first laparoscopic radical resection of RCC in 1990,[3] laparoscopic radical resection has become the standard surgical method for stage T1 RCC.[4],[5] With the improvement in surgical techniques, some studies have reported that intraperitoneal transperitoneal laparoscopic radical resection of RCC can also be used in stage T2 (7–10 cm) RCC.[6],[7] However, larger tumors will pose greater challenges for laparoscopic surgery, in particular, retroperitoneal laparoscopic surgery. Moreover, larger tumors are often more advanced (T3 or later), with more serious adhesions or even renal vein thrombosis. Therefore, open radical resection is conventionally adopted for larger RCC.

However, Fan et al.,[8] therefore, performed a systematic review and meta-analysis of the available published literature (search of PubMed, Embase, and the Cochrane Library) to compare the outcomes of the two approaches. This meta-analysis indicates that in appropriately selected patients, especially patients with posteriorly located renal tumors, the retroperitoneal approach may be faster and equally safe compared with the transperitoneal approach. Then, we gathered the clinical data of 152 patients with a mean body mass index (BMI) of ≤24 and large RCC (Φ >7 cm; clinical stage cT2 or cT3a) who underwent retroperitoneal laparoscopic and open radical resection of RCC in our hospital between January 2003 and January 2013. Our objective was to evaluate the feasibility, safety, and long-term efficacy of retroperitoneal laparoscopic radical nephrectomy (RPNx) of large RCC in comparison to open radical nephrectomy (ONx). Moreover then those outcomes of the first 30 and last 30 number of patients (or the first 5 and last 5 years) in 10 years were divided into segments to look for the differences of a learning curve.


 > Materials and Methods Top


Patients and grouping

First, this retrospective study, gathered the clinical data of 160 patients with a mean BMI of ≤24 and RCC (Φ >7 cm; clinical stage cT2 or cT3a) who underwent retroperitoneal laparoscopic and open radical resection of RCC in our hospital between January 2003 and January 2013, but the number of patients missing from follow-up is 8 (3 patients who underwent RPNx and 5 patients who underwent ONx were missed and excluded). Hence, finally 84 patients, who underwent RPNx for tumors F >7 cm (group 1) having a clinical stage cT2 or cT3a were compared with 68 patients, who underwent ONx (group 2) for tumors with similar size characteristics. Patients with clinical stage cT3b-cT4 and enlarged retroperitoneal lymph nodes were excluded. All retroperitoneal laparoscopic surgeries were performed by two experienced surgeons. The design of the study was retrospective, nonrandomized, as shown in [Table 1] and [Table 2]. The decision to perform RPNx or ONx was based mainly on surgeon's and patients' preference after detailed information about the risk of each procedure. Furthermore, patient size, anesthetic risks (i.e., severe chronic obstructive lung disease, etc.,), and the availability of the laparoscopic surgeon influenced the decision for RPNx or ONx. Ultimately, the determination of those patients who underwent RPNx versus open was determined by operating surgeon, thus, introducing a selection bias into the data. The patients ranged in age from 58 ± 9.2 to 60 ± 11.5 years old. There was no significant difference in their ages, American Society of Anesthesiologists score and sex between the two groups. The patients ranged in BMI from 23 ± 5.3 to 22 ± 4.1. There was no significant difference in the BMI between the two groups (P > 0.05). In view of the mean BMI of Chinese is lower than western peoples (the mean BMI of ≤24),[9],[10] so we can perform those retroperitoneal laparoscopic and open radical resection surgeries easily. This study was conducted in accordance with the Declaration of Helsinki. This study was conducted with approval from the Ethics Committee of Capital Medical University. Written informed consent was obtained from all participants.
Table 1: Patient characteristics of retroperitoneoscopic and ONx

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Table 2: Surgical characteristics and complications of two groups

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The pathologic staging and grading of tumor

The staging and grade of RCC in the two groups are presented in [Table 1], and perioperative characteristics are presented in [Table 2]. The staging criterion that we used was the American Joint Committee on Cancer 2009 version at the beginning of the study. It is an important, independent prognostic factor for RCC according to the Fuhrman classification system for nuclear grade (grades 1, 2, 3, and 4) in RCC, it has been suggested that a simplified three-strata Fuhrman grading system according to the WHO classification (1997), those are well differentiated (grades 1 and 2), Moderately differentiated (grade 3), Poorly differentiated (grade 4).[11],[12] Tumor size and localization (central, peripheral, etc.) had no impact on the operative approach. For the ONx, a standardized extraperitoneal flank incision was performed without rib resection. Adrenalectomy was performed if intraoperative inspection showed suspicious ipsilateral adrenal involvement or the tumor located at the superior pole of the kidney. Renal hilus lymphadenectomy was performed if intraoperative inspection showed suspicious nodal enlargement. Operative time (OT) was recorded from the initial skin incision to the end of wound closure. Our Institutional Internal Board Committee was informed about our study and accepted the performance of it.

The difference of learning curve

We defined the learning curve as the number of last 30 cases required to consistently perform RPN with equal or shorter average OT than the average of the first 30 RPN. Compared with the OT, the hospitalization time (HT), the estimated blood loss (EBL), and the number of cases of nonblood transfusion (NBT) were showed the difference of learning curve between in the first 30 and last 30 number of patients (or the first 5 and last 5 years) in 10 years.

Follow-up

The preoperative preparations were similar for both groups. Postoperative complication should be categorized according to the Clavien-Dindo classification.[13] The patients were followed closely for 1, 3, 6, 12 months after surgery, every 6 months for 2 years and then annually for 5 years including measurements of the patients' recovery parameters, clinical examination, renal function, abdominal ultrasound B-scan, chest X-ray, and if necessary, chest, abdominal computed tomography, and bone scan. The preoperative evaluation and the postoperative follow-up were performed according to the guidelines of European Association of Urology.[14]

Statistical analysis

SPSS 18.0 software (SPSS, Inc., Chicago, IL, USA) was used for the data analysis. For continuous variables, the Student's t-test or the Wilcoxon rank-sum test depending on distribution of data was used. For categorical variables, the Chi-square was applied. The Kaplan–Meier method was used for the survival analysis, and P < 0.05 indicates statistically significant differences.


 > Results Top


The intra- and post-operative complications of two groups

There were no significant differences in age, sex, BMI, or tumor location between the two groups (P > 0.05). Compared with RPNx group, 17 (25%) cases received intra-operative/postoperative transfusions in the ONx group (P < 0.001). Nine (13%) cases experienced intra-operative complications in the ONx group including 1 (1.5%) cases of pleura injury, 3 (4%) cases of peritoneum injury, 1 (1.5%) cases of spleen capsular injury, 4 (6%) cases of renal vein/vena cava injury, while there were only 5 (6%) cases experienced intra-operative complications in the RPNx group, and the difference in two groups was significant (P < 0.001). Three of the intra-operative complications in RPNx group necessitated conversion to open surgery including one due to bleeding from vena cava injury and two due to bleeding from the renal vein. Spleen injury (capsular tears) in one patient undergoing open surgery was also managed by primary repair. There was statistical difference in the number of postoperative complications 7.2% and 16.1% in the two groups, respectively, (P < 0.001), and the ONx group had a higher incidence of wound infection and incisional hernia.

The surgical data of two groups

There were no complications classified as Grade IIIb or higher (Clavien-Dindo classification for surgical complications). Patient and tumor characteristics are summarized in [Table 1]. No statistically significant (P > 0.05) differences were noted between the two groups. Surgical data are shown in [Table 2] and [Table 3]. Although the mean specimen weight and mean serum creatinine postoperative in the two groups were not significantly different, HT, the incision length, EBL, NBT, the analgesic requirement, the postoperative analgesia, and the recovery time of intestinal function were lower in the RPNx group, respectively, (P < 0.001).
Table 3: Recovery parameters of two groups (mean±SD)

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The pathologic feature of tumor

The tumor histology was typically clear cell carcinoma in both groups (68% and 70%, respectively), with no significant difference (P > 0.05). Chromophobe RCC in both groups (10% and 9%, respectively), and the difference was not significant (P > 0.05). Papillary RCC in both groups (22% and 21%, respectively), and the difference was not significant (P > 0.05). The tumor staging and grade were not significantly different in the two tumor groups (P > 0.05). A total of four cases exhibited positive surgical margins (2.4% and 2.9%, respectively, P > 0.05). In a retroperitoneoscopic group, the peritoneal injuries were left untreated while in ONx group they were sutured primarily. Since the tumor location (central, peripheral, etc.) was equally distributed between the groups, it seems that tumor location has no impact on the choice of procedure.

The recovery parameters and survival rates of two groups

The retroperitoneoscopic patients show significantly (P < 0.05) higher recovery parameters during each of the follow-up times (at 1, 3, 6, 12 months, after surgery) than the ONx group at each time. All the recovery parameters after RPNx returned significantly (P < 0.01) faster to baseline status in comparison to those after ONx [Table 3]. Moreover, then the two groups of patients were followed for a similar period (mean 56.3 vs. 58.2 months) after surgery. In the RPNx group, 8 (9.6%) patients exhibited distant metastases, of which three patients died of pulmonary metastasis in postoperative months 50, 53, and 56, respectively, three patients died of liver metastases in postoperative months 40, 46, and 52, and two cases were still alive with bone metastases. In the ONx group, 8 (11.8%) cases exhibited distant metastases, of which three patients died of lung metastasis in postoperative months 42, 47, and 51, respectively, and one case was still alive with lung metastases, and two patients died of liver metastases in postoperative months 33 and 48, respectively, and two cases were still alive with bone metastases. During this time, there were two cases of local recurrence and no incision transplantation in the two groups. The 5-year Overall survival rate was 86% and 82% in the two groups, respectively; the 5-year cancer-specific survival rate was 94.8% and 93.7% in the two groups, respectively; the 5-year recurrence-free survival rate was 91.6% and 92.1% in the two groups, respectively, with no significant difference [P > 0.05, [Table 4].
Table 4: Follow-up results

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The results of learning curve

There was a downward trend in OT, HT, EBL, and NBT during the RPN learning curve. The average OT of the first 30 RPN patients was 5.8 ± 13 h, compared with the average OT of the last 30 RPN patients of 2.3 ± 24 h (P < 0.001). The HT, EBL, and NBT showed significant differences between the first 30 RPN with the last 30 RPN patients [P < 0.001, [Table 5].
Table 5: Learning curve of number of patients in segments (the first 30 and last 30 patients)

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[Figure 1] shows the learning curve as a function of OT by RPN procedure date as a cubic line of best fit (r2 = 0.32). With r2 of 0.18 and 0.30 in linear and quadratic lines, respectively, this was the best fitting of the modeled lines. After the first 26 RPN cases, the average OT reached the average OT of the last RPN cases.
Figure 1: Retroperitoneal laparoscopic radical nephrectomy learning curve of year of patients' outcomes in 10 years in segments (the first 5 and last 5 years): OR time versus date of surgery. OT = Operative time, RPN = Retroperitoneal laparoscopic radical nephrectomy

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 > Discussion Top


With the improvement in surgical equipment and surgeons' skills, the surgical indications for minimally invasive surgery are expanding. With respect to renal surgical methods current advances include: Radical nephrectomy, nephron-sparing partial nephrectomy, and thermal ablative, etc., Kwon et al.[15] believed that for stage T2 RCC compared with open surgery, laparoscopic radical resection of RCC is superior in OT, intra-operative blood loss, recovery time of intestinal function and hospital stay, and the authors reported no significant difference in the incidence of perioperative complications between the two groups. Moreover, laparoscopic surgery did not increase the surgical risk and the incidence of complications. Some studies have also reported that for stage T3a or T3b RCC, even with renal vein and inferior vena cava thrombus, retroperitoneal laparoscopic radical resection of RCC is safe and effective, with good short-term efficacy.[16],[17]

This long-term study retrospectively analyzed cases that underwent retroperitoneal laparoscopic and open radical resection of RCC in our hospital between 2003 and 2013. All patients were followed closely for 1, 3, 6, 12 months, after surgery, every 6 months for 2 years, and then annually for 5 years. The patients were divided into two groups: RPNx or ONx. The safety and advantages of the retroperitoneal laparoscopic technique in the treatment of large tumors and some stage T3 tumors were compared. There were no differences in the patients' characteristics and the pathological characteristics of the tumors between the two groups. In this study, a total of 16 patients had distant metastases, and four cases had positive surgical margins (two cases for local recurrence). We also analyzed the influence of tumor size on the long-term efficacy of retroperitoneal laparoscopic radical resection of RCC and found that tumor recurrence was not affected by tumor size but was closely associated with tumor staging and grade and the histological type of tumor, which was consistent with the findings of international studies.[18],[19],[20]

Although retroperitoneal laparoscopic radical resection of large RCC is feasible and safe and has many advantages compared with open surgery, but retroperitoneal laparoscopic radical resection is challenging and requires surgeons skilled in endoscopic techniques. This study found that compared with RPNx group, the incidence of intra- and post-operative complications were 6% and 13%, 7.2% and 16.1% in the ONx group, respectively, and the difference was significant (P < 0.001). In cases where there was tight adhesion between the tumor and the surrounding tissues or surrounding of the renal pedicle by the tumor, the surgery was particularly more difficult. In this study, 84 in all 152 cases of surgeries were performed by two surgeons skilled in endoscopic techniques in our hospital suggesting that the experience in laparoscopic surgery was crucial to the success and long-term efficacy of laparoscopic radical resection of large RCC. Breda et al.[21] found that complications associated with the laparoscopic management of renal masses vary among the different procedures and with surgeon experience. The rate of complication appears to be similar to that of open surgery.

Fewer studies have assessed the learning curve in retroperitoneal laparoscopic radical nephrectomy. According to an international study,[22] the incidence of complications was decreased from 8.3% to 2.5% between early and late surgeries performed at the same medical center. Given similar baseline tumor characteristics, OT can be viewed as a surrogate for the overall efficiency of the surgeon. As such, we chose to use it as one of our metrics in assessing the learning curve. Our other metric, the volume of EBL, is highly correlated with interoperative patient's security. It is thus the most important surgeon-dependent outcome of retroperitoneal laparoscopic radical nephrectomy. In the study, the learning curve was defined as the number of cases required to reach a plateau, which occurred at 26 cases for OT and 29 cases for EBL. The big differences between the initial 30 with last 30 cases were present indicating that learning curve in such complicated tumors cannot easily be achieved, a long lasting learning curve is present indicating that mastering of such a complicated operation can be challenging.

Although, the weaknesses of the program are a nonrandomized study, single center, and single population with low BMI. Our conclusion is that the RPNx is a safe and effective alternative having less blood loss, postoperative recovery time, or the incidence of intra- and post-operative complications, and shorter hospitalization than ONx (P < 0.001). Retroperitoneal laparoscopic radical resection for large RCC in stage cT2 or cT3a is safe, feasible, and the efficacious procedure produced good long-term results. Furthermore, our mean follow-up of 5 years is long. Since, only for small RCC, it is clearly established that after a median follow-up of 7 years the oncological results between open or laparoscopic surgery are equivalent,[5] so the same follow-up period was mandatory for large tumors to assess comparative oncological outcome then the same results were gotten in my study. However, a long lasting learning curve was presented indicating that mastering of such a complicated operation can be challenging, the RPNx for large renal tumors is a challenging operation, often requiring advanced surgical skills and experience in laparoscopic surgery. Additional prospective multi-center studies with longer follow-up and larger patient numbers are mandatory.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 
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