Introduction
Presently, little distinction is made regarding the technical difficulty grade in laparoscopic rectal surgery. Most studies only refer to the localization of the tumor as a degree for technical difficulty of the operation, leaving many other factors unaccounted for. The distinct difference in male and female pelvic anatomy makes female patients theoretically more suitable for laparoscopic rectal surgery, as there is usually more opportunity to maneuver in the wider pelvic structure. Also, the body mass index (BMI) is a factor to consider when referring to the technical difficulty in laparoscopic rectal surgery, as is the presence of preoperative radiation therapy (RHT), especially when a long delay between radiation therapy and surgery is applied. Although the tumor size is often reduced after a long delay to surgery, the surrounding tissue is frequently fibrotic and difficult to handle.
It may therefore be useful to define the technical difficulty of laparoscopic rectal resections to improve and standardize education for others, to counsel the learning process, for self-evaluation, and to stratify results, making different future publications regarding laparoscopic rectal surgery more comparable.
The aim of this study was to see if laparoscopic rectal surgery could be categorized according to their technical difficulty degree on the bases of preoperatively known facts, such as gender, body mass index, localization of the tumor, and preoperatively administered radiation therapy.
Materials and methods
Patients
Eight factors were prospectively evaluated in 50 consecutive patients who underwent a laparoscopic resection for rectal cancer in the VU University Medical Center. Patients were operated on between April 2002 and November 2005 by the same surgeon and surgical team. Patients who had previous abdominal surgery through a median laparotomy were excluded from this study, as were patients undergoing palliative surgery or surgery for benign tumors.
All patients received the same pretreatment workup, including a colonoscopy with biopsies for rectal examination: rectal ultrasound and magnetic resonance imaging of the rectum for local staging, and X-thorax, computed tomography scan of the abdomen, and cinoembryonic antigen examination for dissemination status. Tumors had to be located within 17 cm of the anal verge, measured by rigid scope following colonoscopy with rectal ultrasound, and were defined according to Goligher [
1]: 7 cm or less from the anal verge, low rectum; over 7 cm but less than or equal to 12 cm, mid rectum; over 12 cm but less than or equal to 17 cm, high rectum.
Before each operation, the following factors were taken into consideration: male or female pelvis, body mass index, localization of the tumor in centimeter from the dentate line, and whether preoperative radiation therapy was administered. These factors were subsequently compared to the following operative outcomes: length of operating time, blood loss, whether the tumor was radically resected (circumferential margin >2 mm), and a visual analogue score (VAS) for difficulty from the surgeon, ranging from one through ten, with score one being the easiest laparoscopic operation ever performed by the surgeon and score ten being a conversion to laparotomy.
We consequently reviewed whether the preoperatively determined parameters could predict the difficulty grade of the operation, expressed in terms of the operative outcomes. On the basis of postoperative outcomes regarding the preoperatively known patient characteristics, we created a point system as a reference for technical difficulty grade for laparoscopic total mesorectal excisions (TMEs).
Collected data
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Patient data: gender, age, body mass index, localization of the tumor, and preoperative radiation therapy
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Operative data: operating time, blood loss, VAS for difficulty by the surgeon, and oncological radicality of the procedure
Statistical analysis
Statistical analysis was performed using the SPSS software package (SPSS 11.5 for Windows; SPSS, Chicago, IL, USA). Medians and interquartile ranges were calculated and subsequently depicted when appropriate. Spearman’s correlation, the Mann–Whitney U test, the Kruskal–Wallis test, chi-squared test, or Fisher’s exact test were applied when appropriate for group comparisons. Significance was set at P < 0.05.
Discussion
The fact that a learning curve exists for different operations, especially in laparoscopic surgery, is generally well known and has been extensively published from the onset of laparoscopic surgery [
2]. Some publications have suggested that the learning curve for colorectal laparoscopic surgery ranges from 11 to 80 procedures performed [
3‐
5]. However, presently, no series trying to support and counsel surgeons by optimizing their learning curve have been published.
Geis et al. [
6,
7] studied the relative difficulty of seven laparoscopic colonic procedures, differentiating in three complexity scales in laparoscopic colectomy: mobilization, devascularization, and anastomosis, which could define the complexity rating for every procedure. They also concluded that, for different laparoscopic colon procedures, different skills can be learned sequentially if patients are chosen judiciously. Therefore, not only the number of procedures but also the difficulty grade of the intervention will play an important role in the buildup of the learning process for a specific surgeon or team. They advised for one to obtain extensive experience in laparoscopic right colon mobilization and sigmoid colon mobilization before performing left colon resections, low anterior resections, and APRs laparoscopically.
In evaluating the learning curve in laparoscopic colorectal surgery, Tekkis et al. [
8] used a multidimensional analysis of the learning curve and compared outcomes between right-sided vs. left-sided colonic resections. They concluded, regarding right-sided and left-sided colonic resections, that it is possible to perform more difficult laparoscopic operations with increased experience without an influence on postoperative morbidity; also, body mass index is a predictive factor in conversion rates and operating time is reduced with experience gained by the surgeon.
Senagore et al. [
9] analyzed the learning curve in three consecutive groups of 20 patients and, as expected, found that not only did the number of complications and conversions decreased with experience but more complex surgical resections were also performed with greater ease as surgeons gained more experience. Therefore, it seems important to define the difficulty or complexity grade of a relatively new procedure like the laparoscopic TME.
In the present study, according to the VAS for difficulty, surgeons found the male pelvic anatomy more difficult to operate; however, this was not expressed in terms of a longer operating time, more blood loss, or fewer radical resections. Lower tumors were more difficult to operate when reviewing the operating time, blood loss, VAS for difficulty rewarded by the surgeon, and in the amount of radical resection. Only less blood loss was seen in patients with a BMI of 25–30; operating time, VAS for difficulty rewarded by the surgeon, and oncological radicality of the procedure were comparable for patients with a BMI of 25–30 and a BMI > 30. Preoperative radiation therapy was found to be accompanied by a longer operating time, more blood loss, a higher VAS for difficulty rewarded by the surgeon, and less radical resections of the tumor.
Not only to advise in the proper way to start, and in an attempt to standardize the learning curve, but also to stratify the different procedures involved in rectal resections to make future study results more comparable, we categorized laparoscopic rectal surgery into three groups of patients, according to their technical difficulty grade: “low-score patients” (scores 6–11), “medium-score patients” (scores 12–24), and “high-score patients” (scores 25–37). We found that there was a significant association between length of surgery, blood loss, VAS for difficulty rewarded by the surgeon, including oncological radicality of the procedure, and the low, medium, and high technical difficulty grade scores for patients, indicating that the score is representative for the technical difficulty grade experienced by the surgeon in the present study.
When reviewing some of the major literature on learning curves in colorectal surgery, the mean number of operations needed within a learning curve is approximately 45 [
2‐
5]. We would therefore suggest for the surgeon to have performed at least 25 operations in the easy technical difficulty grade scores (6–11) and, if the surgeon is confident, to move on to the medium technical difficulty grade scores (12–24). After approximately 25 more operations, the learning curve should be mostly completed and the surgeon could consider moving on to patients with high technical difficulty scores (25–37).
Realizing that the results of the present study were obtained by a surgeon and surgical team who had experience with laparoscopic surgery, the results may have therefore been biased due to their experience. However, we still think that it is important to introduce a technical difficulty grade in the future to better facilitate and standardize teaching purposes, self evaluation, and ultimately patient safety, also for adequate stratification of results in future studies regarding laparoscopic rectal procedures.
We found that the technical difficulty grade score system in the present pilot study could preoperatively predict the difficulty grade of laparoscopic rectal surgery. Surgeons and residents still within their learning curve for laparoscopic TMEs could therefore preoperatively select patients with less difficult procedures and slowly move forward to more complex procedures in a controlled fashion. The present study is a single-institution pilot study; therefore, larger studies need to be conducted for more definite results.