Our survey among practicing surgeons in Sri Lanka showed that less than one fourth of the surgeons who had the necessary facilities performed laparoscopic surgery for CRC. As these laparoscopic surgeons also performed open procedures the actual laparoscopic colectomy rates would be much lower than the percentage of surgeons who perform laparoscopic procedures for CRC. In South Asian countries like Sri Lanka the laparoscopic colectomy rates remain low due to many reasons. A large study from a high-volume center in India [4] and a smaller study from Sri Lanka [5] have shown that nearly 80% of tumors are advanced at the time of presentation. One of the reasons for low laparoscopic colectomy rates in this part of the world is concern about the adequacy of locoregional clearance in these advanced tumors. Other reasons include lack of adequate training and facilities for advanced laparoscopic procedures. In contrast there is a steady increase in the adoption of laparoscopy for CRC surgery worldwide with the US showing an increase from 22.7% to 49.8% from 2007 to 2014 [1]. In the UK there has been an increase in laparoscopic CRC resections 48% to 61% from 2013/14 to 2019 [2]. In Netherlands over 60% of patients undergo laparoscopic resections for CRC [3]. In our study we compared our first 81 patients who underwent laparoscopic surgery with the last 56 patients who underwent open surgery. Although the surgeons who performed these procedures were much more experienced in open surgery the laparoscopic surgery group had a significantly higher LN harvest than the open group. This difference may be due to better visualization and skeletonization of the pedicles in laparoscopic group. The retrieved and number of assessed lymph node harvest in majority of patients in both groups was higher than the threshold of 12 lymph nodes, recommended by the American Joint Committee on Cancer (AJCC) [6]. Furthermore, in our study the longitudinal margins and CRM were comparable in the two groups. Overall, our findings emphasized that adequate tumour margin and better lymph node harvest can be obtained with laparoscopic colorectal cancer surgery in both colonic and rectal cancer surgery.

Our study was not a randomized controlled trial. However, the histo-pathological findings would not have been significantly affected, as the pathologists who examined the specimens were not aware whether the operation was open or laparoscopic. A few previous studies have shown that the mean number of harvested lymph nodes was significantly higher in laparoscopic than in open surgery [7,8,9]. Our findings are similar to theirs. However, some studies have shown no difference between the number of LN resected in open and laparoscopic surgery [10,11,12]. It is not clear whether the two groups of patients included in these previous studies were operated on by the same surgeons.

In our study the longitudinal margins and CRM were comparable in the laparoscopic and open surgery groups. A few previous studies have also shown comparable CRM in LR and OR, with no positive distal margins in either group [9, 13]. Our findings are very similar to theirs.

Most previous studies have compared either the lymph node harvest or the resection margins in LR and OR. Both these aspects were evaluated in our study. Both CRM and LN clearance are important for tumour staging and prognostication at the time of surgery. In our study a single surgical team operated on all patients and processing and examination of resected specimens was done by a single histopathology team thus eliminating undue bias. Patients were followed up for 3 years and there was no significant difference in both overall and disease free survival between the two groups. Previous studies have shown comparable recurrence and survival rates in laparoscopic and open surgery [12,13,14]. The significantly better LN clearance in our study could be attributed to the more precise high resolution and brighter image which allows the surgeon to perform a more radical and precise resection of the mesocolon and mesorectum, while facilitating an accurate and complete lymphadenectomy with higher transection of the vascular pedicles. Earlier studies may have failed to show better LN clearance in LR due to poorer optics at the time these studies were done.

In spite of the knowing the benefits of laparoscopic surgery for CRC the majority of surgeons practicing in Sri Lanka showed a reluctance to adopt this approach. One of the reasons was their concern about the adequacy of adequate locoregional tumour clearance and survival in view of the fact that tumours in this part of the world are more advanced at the time of presentation. Our study showed that comparable tumour clearance, better nodal clearance and acceptable survival rates could be obtained in laparoscopic colorectal cancer surgery. The findings of this study are likely to encourage more South Asian surgeons to adopt the laparoscopic approach thereby increasing the proportion of laparoscopic procedures performed which would result in better patient outcomes.

In conclusion, this study highlights the fact that satisfactory oncological outcomes including clear margins, lymph node harvest and survival rates can be obtained with laparoscopic colorectal cancer surgery in a South Asian developing country.