Initial retrocolic endoscopic tunnel approach: A promising technique for radical right hemicolectomy.

Background: Complete mesocolic excision with central vascular ligation for colonic cancers improves overall survival. To achieve better short term and oncological results, different laparoscopic techniques have been described for right-sided colonic cancers. Laparoscopic right hemicolectomy by the Initial Retrocolic Endoscopic Tunnel Approach (IRETA) is proposed to be easy and offer desired oncological resection; we present our results with IRETA. Patients and
Methods: The data of all patients who underwent right hemicolectomy by IRETA for colonic cancer between January 2019 and March 2020 were retrospectively analysed for demographics, clinical features, oncological completeness of resected specimen, complications, hospital stay, morbidity and mortality.
Results: A total of eight patients (05 males and 03 females) were identified. The mean operating time was 190 ± 32.40 minutes. Margins of all resected specimens were free of tumour except for one in which retro-peritoneal circumferential resection margin was positive. On average 13.75 ± 2.63 lymph nodes were retrieved. Except for wound infection in one patient, no other morbidity was seen.
Conclusion: Laparoscopic radical right hemicolectomy by IRETA is safe and gives desired oncological results.

INTRODUCTION

Based on the concept of total mesorectal excision for rectal cancers, Hohenberger et al. introduced the concept of complete mesocolic excision (CME) with central vascular ligation (CVL) for colonic cancers. This technique involves colonic resection in an avascular embryonic plane with ligation of vascular pedicles at their origin resulting in satisfactory three-dimensional tumour margins and adequate lymph node retrieval thus minimising the chances of local recurrence.[1]

Laparoscopic right hemicolectomy (LRH) with an advantage of early recovery, is associated with similar oncological results when compared to the open procedure.[2] Various methods have been explained in the literature for LRH like medial to lateral approach (Senagore), lateral to medial approach or modification of these techniques.[34] Subbiah et al. (2016) proposed the modification of medial to the lateral technique known as (Initial Retrocolic Endoscopic Tunnel Approach [IRETA]) for LRH. This involves dissection through mesofascial planes of mesocolon with the formation of retrocolic tunnel as an initial step, followed by vertical dissection along superior mesenteric vessels to ligate vascular pedicles at the site of their origin/drainage for complete mesocolonic excision.[2] In this article, we share our initial experience of IRETA, a technique for LRH.

PATIENTS AND METHODS

In our hospital, which is a tertiary care hospital of North India, we started doing LRH by IRETA from January 2019 onwards. The data of all patients who underwent LRH by IRETA for right-sided colonic cancer between January 2019 and March 2020 were retrieved. These patients were assessed for demographics, clinical features, oncological completeness of resected specimen, complications, hospital stay, morbidity and mortality.

Preoperatively bowel preparation (polyethylene glycol 1 sachet in 2 L water) was given to all patients apart for thromboprophylaxis and prophylactic antibiotics. Before surgery, all patients were catheterised to avoid inadvertent injury to the bladder while suprapubic port insertion.

Operative technique

Patients were operated in supine posture, and position of table was changed depending on part of bowel to be mobilised. Retrocolic tunneling and mobilisation of caecum and ascending colon was done in Trendelenburg position whereas hepatic flexure mobilisation was done in reverse Trendelenburg position. Both upper limbs of the patient were tucked by side of the operating table. The surgeon and camera person stand on the left side of the patient and assistant and nursing staff on the opposite side. Pneumoperitoneum was created with the help of veress needle and four ports were used to complete the whole procedure [Figure 1]. Suprapubic port was used for camera except during mobilisation of hepatic flexure when it was shifted para umbilical port.

Figure 1

Port position

Initial retrocolic dissection and mobilisation of the colon

Greater omentum is positioned in the supracolic compartment to expose the transverse mesocolon. Small bowel is shifted onto the left side of the abdomen to expose the mesentery of small bowel from its root till DJ flexure. Anterior and cranial traction is given to caecum to expose the peritoneal reflection onto the caecum [Figure 2]. Beginning at caecal peritoneal reflection, incision is made over peritoneum and continued over mesentery of small bowel along the mesenteric axis with ultrasonic shear to open up avascular plane between fascia enveloping the mesocolon above and Toldt's fascia below. Presence of spider web like avascular tissue confirms the correct plane [Figure 3]. During this dissection, anterior traction is applied holding the mesentery of small bowel and posterior traction is given by pushing the Toldt's fascia. Right ureter and gonadal vessels can be identified running beneath the Toldt's fascia.

Figure 2

Cranial traction on mesentry of small bowel to expose caecal peritoneal reflection and root of mesentary upto duodenojejunal flexure

Figure 3

Opening the avascular plane between Toldt's fascia below and mesocolic fascia above to form retrocolic tunnel

Dissection is continued cranially and medially to expose the head of the pancreas medially and Gerota's fascia laterally. The junction of the first and second part of the duodenum marks the upper limit medially. Laterally, the dissection is extended to lateral peritoneal reflection [Figure 4]. Surgical gauze is then placed over the duodenum and head of the pancreas to prevent inadvertent injury to the duodenum during vascular pedicle dissection and ligation.

Figure 4

Extent of retrocolic dissection (D1D2-first and second part of duodenum)

Vascular pedicle dissection and high ligation

Small bowel is positioned back to its anatomical configuration. Anterolateral traction is applied over the mesentery of small bowel and the transverse colon is lifted anterosuperiorly by the assistant to identify the ileocolic pedicle. The pedicle is dissected off mesenteric fat and dissection is continued till its junction with superior mesenteric vessels [Figure 5]. Surgical gauze previously placed acts as an indicator to protect the duodenum from injury while dissection at this stage. Artery and vein are dissected separately and clipped at their junction with superior mesenteric vessels.

Figure 5

Dissection of ileocolic pedicle till its junction with superior mesenteric vein

The traction is maintained on the transverse colon and dissection is further continued cranially along the lateral border of the superior mesenteric vein (SMV) to dissect the right colic pedicle, if present and right branch of the middle colic artery [Figure 6]. After this, veins draining into SMV are dissected and ligated. One must be careful at this juncture because of marked variation in venous anatomy in this region and the presence of the gastrocolic trunk of Henle.[5] Injury to the major vein in this region can lead to torrential haemorrhage.

Figure 6

Clipped and divided right colic and middle colic vessels at their origin (RCA: Right colic artery, rMCA: Right branch of middle colic artery, MCV: Middle colic vein)

Hepatic flexure and transverse colon mobilisation

Patient in reverse-Trendelenburg position with camera in paraumbilical port, with downward traction on the greater omentum, gastrocolic ligament is divided from medial to the lateral direction along the greater curvature of the stomach and reaching till lateral attachment of hepatic flexure to the abdominal wall. Greater omentum is bisected up to the level of transverse colon transection. The patient is again positioned in the Trendelenburg position with right side up, the final attachment of colon along the white line of Toldt is detached to complete the mobilisation of the specimen.

Specimen extraction and anastomosis

The mesentery of the ileum and transverse colon is divided at the level of transection. The bowel is transected intracorporeally or extracorporeally depending on the type of anastomosis to be performed. For extracorporeal anastomosis, a small incision is made with few centimetres above and below the umbilicus. With plastic bag in place, the specimen is extracted and extracorporeal transection and anastomosis with 3-0 polyglactin suture is done. For intracorporeal anastomosis, bowel transection and side to side ileocolic anastomosis can be done using endo GIA staplers. After enterotomy closure, the specimen can be retrieved through a small suprapubic incision. The mesenteric defect is closed to prevent internal herniation of the bowel through the defect.

Post-operatively in our patients, nasogastric tube and catheter were removed on postoperative day 1 and patients were encouraged to ambulate the same day. Oral intake was allowed on the 3rd day.

RESULTS

From January 2019 to March 2020, eight patients underwent LRH by IRETA for right-sided colonic adenocarcinoma. The mean operating time was 190 ± 32.40. On histological assessment, margins of all specimens were free of tumour except for one in which retro-peritoneal circumferential resection margin was positive. Peroperatively, in this patient, the tumour was densely adherent to retroperitoneum. The intra-corporeal anastomosis was done in only one patient. On average 13.75 ± 2.63 lymph nodes were retrieved. Except for wound infection in one patient, no other morbidity was seen [Table 1].

Table 1

Patient characteristics

Age/sex	Site of tumor	CRM (retro peritoneal)	Lymph nodes retrieved (n)	Hospital stay (days)	Morbidity
53/male	C	Negative	14	5	Nil
63/male	C+AC	Negative	13	6	Nil
48/male	C	Negative	11	6	Nil
56/female	C+AC	Positive	9	7	Nil
68/female	HF	Negative	15	5	Nil
50/male	C+AC	Negative	18	6	SSI
59/female	C+AC	Negative	14	5	Nil
60/male	AC+HF	Negative	16	6	Nil

C: Caecum, AC: Ascending colon, HF: Hepatic flexure, CRM: Circumferential resection margin, SSI: Surgical site infection

DISCUSSION

CME with CVL for colonic cancers ensure complete removal of tumour-bearing area of bowel in all three dimensions with maximum lymph node retrieval.[6] This not only helps in better disease prognostication but also improves disease-free and overall survival. Hohenberger et al. in the year 2009, reported 5-year disease-free survival rate of 89% (75.9% in non-CME Group) with a local recurrence rate of 3.6% (6.5% in non-CME Group) in 1329 patients who underwent CME with CVL for right colon cancers.[1] Similarly, Bertelsen et al. found that CME conferred risk reduction in terms of local recurrence to 8.2% as compared to 17.9% in non-CME patients and therefore, recommended CME to be standard of care in right-sided colon cancers.[7]

The oncological results of LRH are comparable to open procedures. However, laparoscopy with proven benefits of decreased hospital stay and post-operative pain, better cosmesis, decreased wound-related complications and better quality of life, is always superior to open surgery.[6] Since 1991, when LRH was first performed, various techniques are described in the literature for LRH like medial to lateral, lateral to medial, top to bottom or bottom to top approach.[4] Medial to lateral technique is preferred as it is associated with shorter operative time and lesser chances of conversion.[8] Subbiah et al. (2016) described a modified version of medial to lateral approach, based on the principles of CME and CVL for LRH by the name IRETA and reported that with this technique CME could be achieved in 93.8% of patients, with an average of 24 lymph node retrieval.[2]

In our experience, we found IRETA not only helps in achieving desired oncological results but is also safe and easy to learn. Medial and lateral attachments as maintained during the initial part of the procedure make separation of mesocolon from Toldt's fascia easier. Initial retrocolic tunnelling also helps in early visualisation of the ureter, gonadal vessels, duodenum and SMV and thus reducing the chance of injury to these structures. Further, for CME, it is important to identify the avascular plane between mesocolic and parietal fascia. CME can be better achieved with this technique as the avascular plane is identified before ligation of vascular pedicles. Inadvertent bleeding while ligating vessels before mesocolic separation can spoil this plane and can result in incomplete mesocolic excision. The role of lymph node retrieval in local recurrence is still questionable but to know lymph node status in colorectal cancer, evaluation of a minimum of 12 nodes is required to accurately identify the early stage.[9] As vessels are ligated close to the site of their origin/drainage, the chances of harvesting the maximum number of lymph is also not compromised with IRETA.[4] Thus, it ensures radical surgery for carcinoma of right colon.

The only limitation of the present study is small sample size. Therefore, large multicentric studies which compare this technique with other techniques of LRH are needed, before IRETA can be accepted as the standard laparoscopic procedure for right-sided colonic cancers.

CONCLUSION

LRH by IRETA is not only safe and easy but also give desired oncological results. However, to further validate this multi centric comparative studies on large number of patients is recommended.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.