Laparoscopic surgery for right colon cancer with intestinal malrotation

A case report and review of the literature

Abstract

Intestinal malrotation (IM) results from abnormal midgut rotation during embryogenesis and usually presents in early infancy. IM in adults is often an incidental radiological diagnosis. Right colon cancer with IM has been sparingly reported in the world literature. Only 44.7% of these documented cases underwent successful laparoscopic resection, all of which were reported from Japan. The presence of aberrant anatomy and altered vascular orientation in IM presents challenges for laparoscopic resection with adequate nodal clearance. We present the case of a 72-year-old female diagnosed with carcinoma of the ascending colon, with IM incidentally detected on pre-operative cross-sectional imaging. She underwent laparoscopic right hemicolectomy. We also reviewed the documented cases of successful laparoscopic surgery for right colon cancers with IM. Aided by accurate delineation of vascular anatomy on pre-operative cross-sectional imaging, laparoscopic colectomy in the setting of IM is safe and feasible, and should be favourably considered.

INTRODUCTION

Laparoscopic resection for colon cancer has been widely adopted given the advantages of minimally invasive surgery, with oncological outcomes equivalent to open surgery.[¹] Intestinal malrotation (IM) is a congenital anomaly that presents with intestinal obstruction or mid-gut volvulus in infants, but frequently remains asymptomatic, and therefore, undetected, in adults. The incidence of right colon cancer in the setting of IM is quite rare, with only 38 cases having been reported worldwide. The optimal surgical approach and safety of laparoscopy in this situation have not been established, and only 17 of the reported cases were managed laparoscopically, incidentally all from Japan.

We report the case of an adult with ascending colon malignancy and IM, managed with laparoscopic hemicolectomy. This is, to our knowledge, the first reported case from the outside of Japan.

CASE REPORT

A 72-year-old female presented with exertional dyspnoea and retrosternal discomfort for 2 days. She had a 2-month history of anorexia and weight loss preceding this, with no history of gastrointestinal bleed. She was haemodynamically stable at presentation. A coronary pathology was initially suspected; electrocardiogram and cardiac enzyme assays were normal. Echocardiogram showed preserved cardiac function with no features of acute coronary syndrome. She was found to be anaemic (Hb 5.5 g/dL) and presumed to have secondary circulatory dysfunction. She was transfused blood and evaluated for the sources of ongoing blood loss. Colonoscopy identified an ulcerated polypoidal growth in the proximal ascending colon, the biopsy of which showed moderately differentiated adenocarcinoma. Contrast-enhanced computed tomography (CT) scan of the abdomen revealed a tumour in the ascending colon. There was evidence of mid-gut malrotation with the caecum located in the midline, duodenojejunal flexure to the right side of the spine, and rotation of the superior mesenteric vessels with the superior mesenteric vein located to the left of the superior mesenteric artery (SMA). Assessment of vascular anatomy showed a large ileocolic branch originating from the right side of the SMA. There was no significant vessel supplying the right colon arising from the left side of the SMA [Figure 1a-c].

Figure 1: Pre-operative contrast-enhanced abdominal computed tomography images. (a) Axial image showing abnormal rotation of superior mesenteric vessels with SMV located to the left of the SMA (thick black arrow). (b) Axial image showing caecum located anteriorly and in the midline with circumferential tumour (T) in the proximal ascending colon. (c) Maximum intensity projection images showing the course of the SMA (thick black arrow) and large ileocolic artery (thin black arrow) arising from its right side. SMA: Superior mesenteric artery, SMV: Superior mesenteric vein

After adequate pre-operative optimisation, she underwent laparoscopic surgery. The port position was modified anticipating the abnormal location of the right colon [Figure 2]. Intra-operatively, the anterior midline position of the caecum and ascending colon was confirmed. The hepatic flexure was sub-hepatic in the location, and small bowel loops were located in the right half of the abdominal cavity. A mass was noted in the proximal ascending colon, and there were no metastatic deposits. Flimsy adhesions anchoring the right colon were divided and hepatic flexure mobilised medially; the duodenum was encountered, covered anteriorly by a Ladd's band running from the right posterior abdominal wall to the ascending colon [Figure 3a]. After the division of the band, the duodenum was seen descending vertically with no formed ligament of Treitz, and the duodenojejunal junction was represented by an acute bend to the right of the midline [Figure 3b]. Incomplete malrotation was established based on these findings [Figure 3d]. There were adhesions between the caecum and the mid-transverse colon, which were released. Adhesiolysis was performed to straighten the duodenojejunal junction. Intracorporeal mesenteric excision and ligation of vascular pedicles (i.e., ileocolic and right colic) was done [Figure 3c]. The specimen was exteriorised through a small midline incision and bowel resection was completed with hand-sewn ileo-transverse colic anastomosis. The patient had an uneventful recovery and was discharged on the sixth post-operative day. Histopathological examination showed high-grade mucinous adenocarcinoma, pT3N1, with 1 out of 12 lymph nodes positive for tumour.

Figure 2: Schematic of laparoscopic port placement. 1: 10 mm optic port. 2 and 3: 5 mm working ports. 4 and 5: Additional 5 mm ports for retraction

Figure 3: Intraoperative images during laparoscopic right hemicolectomy. (a) After mobilisation of the right colon, Ladd's band (thick black arrow) seen running from the ascending colon (A) towards the right posterior abdominal wall. (b) Duodenum (D) descending vertically to the duodenojejunal junction (thick black arrow), making an acute bend and continuing as the proximal jejunum (J). (c): Laparoscopic mesenteric dissection done. Ileocolic artery (thick white arrow, a) and right colic pedicle (black arrowhead) have been clipped and divided at the origin. Ileocolic vein (thick white arrow, v) clipped. (d) Schematic depiction of anomalous anatomy with incomplete malrotation. T: Tumour in the ascending colon

DISCUSSION

IM results from abnormal rotation and fixation of the midgut during embryogenesis. Depending on the degree of rotation, there are numerous variations, broadly classified into non-rotation, incomplete malrotation and reverse rotation with sub-types based on the orientation of the duodenum and colon.[²] The reported incidence varies widely with autopsy series suggesting an incidence of 0.5%.[²] IM usually manifests with intestinal obstruction in the neonatal period. The incidence in adults is difficult to establish, as these patients are often asymptomatic and IM, usually the non-rotation type, is incidentally detected on imaging or at the time of an unrelated abdominal operation.

A literature search revealed 59 reported cases of colorectal cancer with IM (excluding situs inversus totalis) from 1970 to 2021, of which 50 cases have been reported from Japan.[³⁴⁵] Among these, in 38 instances (64.4%), the tumour was located in the right colon, including the appendix. Laparoscopic resection was only performed in 17 (44.7%) of these patients Table 1, mainly due to concern for vascular anomalies that may hinder a safe resection and abnormal lymphatic drainage that may impede a complete lymphadenectomy.

Table 1: Review of literature of cases of right colon cancer with intestinal malrotation treated by laparoscopic surgery[^{3 4 5}]

In nine cases, mesenteric excision and lymph node dissection were performed extra-corporeally after laparoscopic adhesiolysis. With the advent of high-quality cross-sectional imaging in the form of multidetector CT angiography and three-dimensional reconstruction, it is possible to not only diagnose IM pre-operatively but also understand abnormal vessel orientation and plan a sound lymph node clearance. Bolstered by technological advances and increasing levels of prowess in minimally invasive surgery, more challenging procedures are progressively being performed laparoscopically. This case demonstrates that laparoscopic right hemicolectomy may safely be attempted in a setting of IM. Modifications in operative strategy may be required, such as adjustments in port positioning and adoption of a lateral-to-medial approach, thereby splaying out of the mesentery to better delineate vascular anatomy before proceeding to tackle the vascular pedicles. Inter-loop adhesions are often present, as in this case, and they may be dissected laparoscopically with care. Mesenteric dissection and ligation of vessels may also be safely performed. Once the retroperitoneal adhesions and Ladd's band are divided, the specimen is easily deliverable outside the abdominal cavity for bowel transection and anastomosis. A formal Ladd's procedure with widening of the small bowel mesentery is not required as the right colon is being removed.

In conclusion, laparoscopic hemicolectomy is safe and reliable in patients with right colon cancer and IM. The procedure requires an accurate assessment of anatomy with good quality pre-operative imaging and complete lymphadenectomy may be performed intra-corporeally.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.