Robot-Assisted Surgery for Reversed Intestinal Malrotation with Concurrent Cecal Carcinoma: A Case Report

Introduction

The incidence of intestinal malrotation is 1 in 10 000 individuals, and reversed intestinal malrotation is extremely rare, accounting for approximately 4% of all intestinal malrotations [1]. In Japan, robot-assisted colorectal cancer surgery has been covered by health insurance since April 2018 for patients with rectal cancer and since April 2022 for those with colon cancer. The application of robotic-assisted colorectal cancer surgery is expected to increase nationwide. To date, there have been no reports of robot-assisted surgery (RAS) for cecal cancer with reversed intestinal malrotation. Because we consider RAS for this condition to be very valuable, we aimed to report our clinical experience using this technique.

Case Report

An 84-year-old Japanese man presented to a local physician with epigastric pain and abdominal distention. Abdominal radiography and plain computed tomography (CT) revealed small bowel obstruction and a hepatic mass. He was referred and admitted to the Department of Gastroenterology at our hospital for a thorough examination. Colonoscopy revealed a semicircumferential type 2 tumor in the cecum and ascending colon. A Gastrografin contrast study in the spine position showed that the large intestine was entirely on the patient’s right side and the small intestine was shifted to the left side, suggesting reversed intestinal malrotation (Figure 1). Contrast-enhanced CT revealed the main tumor at the right lower quadrant of the abdomen (Figure 2A), and the distention of the oral ileum, which was thought to be the starting point of the obstruction (Figure 2B). CT scan also showed enlarged lymph nodes near the tumor and masses were observed at S7 and S8 of the liver, which were believed to be metastases. The maximal size of the liver metastasis was 38 mm. Following examination, a nasal ileal tube was inserted for intestinal decompression. After 10 days from ileal tube insertion, because the distention of the ileum had improved, the patient was referred to our department for surgery and underwent robot-assisted ileocecal resection with D3 lymphadenectomy. The detailed surgical steps are shown in Table 1. Figure 3 shows the placement of the trocars. As indicated in the preoperative study, the intraoperative overview of the abdominal cavity showed the large intestine located on the patient’s right side and the small intestine on the left side. The Ladd ligament was not observed. The descending colon was fixed to the right abdominal wall and the ascending colon was located to the left of the descending colon, with extensive mesenteric adhesions. The ascending mesocolon was dissected and mobilized by mono-polar curved scissors using an inferior approach. After sufficient lymph node dissection was performed, the ileocolic vein and artery were resected. After confirming that the mesentery has been sufficiently widened from the ileum to the ascending and transverse colon, the reconstruction was performed extracorporeally using the functional end-to-end anastomosis method, using an autosuture device (Figure 4A–4D). The operative time was 232 min, and blood loss was minimal. The patient was discharged on the sixth postoperative day, without complications. The resected specimen showed an elevated type 5 (1+2) lesion with recessed area at cecum (87×60 mm) (Figure 5A). Microscopic examination showed that tumor cells infiltrated the subsereosal layer as well as the terminal ileum (Figure 5B). The proximal and distal margins were considered to have no malignancy. According to the Japanese Classification of Colorectal, Appendiceal, and Anal Carcinoma 9th edition [2], the pathological diagnosis was pT4b (ileum), pN1b, cM1a (H1 (grade A)), and pStage IVa cancer. After discussion with the patient and his family, the decision was made to provide the best supportive care without radical chemotherapy, considering the patient’s poor physical strength.

Discussion

During embryonic organogenesis, the intestinal tract, which is almost straight at 4 weeks of gestation, rotates 270° counterclockwise around the superior mesenteric artery (SMA) from gestational week 5 to 11, and the ascending and descending colons are fixed to the retroperitoneum. Intestinal malrotation is an abnormality of the rotation and fixation phases and can be classified as the nonrotation type (90° rotation), malrotation type (180° rotation), reversed type (reverse type), and paraduodenal hernia [3]. Amir-Jahed classified reversed intestinal malrotation into 4 types according to the position of the colon, SMA, and cecum: I: pre-arterial right-sided cecum, II: pre-arterial left-sided cecum, III: retro-arterial right-sided cecum, and IV: retro-arterial left-sided cecum [4]. In the present case, it was diagnosed type II by enhanced-contrast CT and a Gastrografin contrast study.

When surgical treatment for colorectal cancer with intestinal malrotation is performed, lymphadenectomy is problematic because of the anatomical location of the intestinal tract and its abnormal vascularization. However, even in patients with colorectal cancer with intestinal malrotation, the origin of the SMA or inferior mesenteric artery (IMA) and the interrelationship between each artery and the dominant intestinal tract are normal, allowing lymphadenectomy along the major vessels. In the present case, although the IMA was deviated to the patient’s right side due to a reversed intestinal malrotation, the origin of the SMA and IMA was normal (Figure 6). Certainly, the surgical field would have developed differently than usual, making it essential to conduct numerous simulations using preoperative imaging.

A search of the bibliographic databases Igaku Chuo Zasshi and PubMed using the keywords “reversed intestinal malrotation”, “colorectal cancer”, and “surgery” yielded only 4 reports of surgery for colorectal cancer with reversed intestinal malrotation [5–8]. All reports were from Japan. Cases included cancers of the cecum, transverse colon, sigmoid colon, and sigmoid rectum, with 1 case treated by laparotomy and 3 treated by laparoscopic surgery (one by a single incision). In all cases, the procedures were performed safely, with careful preoperative imaging and simulation, and had favorable postoperative courses (Table 2).

RAS using a surgical robot has features that are not available in conventional laparoscopic surgery, such as forceps capable of a wide range of motion by multiple joints, an anti-shake mechanism, high-resolution 3-dimensional imaging, and functions including image stabilization and motion scaling. These features can anticipate and overcome the problems of laparoscopic surgery by enabling accurate and precise surgery with less invasiveness and allowing more freedom for intervention for the surgeon [9]. The aim of colon cancer surgery is to ensure complete mesocolic excision. The concept of complete mesocolic excision is similar to that of lymphadenectomy, also known as “Japanese D3 dissection” [10]. We believe that RAS allows “accurate tracing of the dissection layer” with greater precision than laparoscopic surgery does. The articulating function of the monopolar scissors of the surgeon’s right hand and “third arm” allows the blade tip to contact the tissue at the angle intended by the surgeon, which can be useful in dissecting physiological adhesions and dissectible layers. In our case, despite the extensive physiological adhesion between the mesentery of the colon caused by reversed intestinal malrotation, we were able to properly identify the dissecting layer and perform D3 lymphadenectomy safely and reliably. In spite of these advantages of RAS to conventional laparoscopic surgery, the efficiency signified by operation time or intraoperative blood loss could not be demonstrated from a review of previous literature, as shown in Table 1. We consider that this is a limitation, and a further accumulation of cases will be necessary in order to prove the advantages of RAS to conventional laparoscopic surgery.

Because colon cancer has a large surgical field, it is important to consider the target anatomy and trocar settings to prevent interference between the forceps and the scope. In our case, the colon was placed entirely on the patient’s right side, leading to the judgment that the surgical field should be centered on the right side. The trocar setting was the same as that used for robot-assisted right colon resection, which is routinely performed in our department. Consequently, a stress-free surgical field intervention and forceps manipulation were possible.

Conclusions

In conclusion, our experience shows that RAS might be one of effective approaches for performing manipulation of dissecting adhesion. Therefore, RAS could be useful for patients with a history of laparotomy and for predicting preoperative intra-abdominal adhesions. With the availability of insurance coverage for robotic-assisted colon cancer surgery, the number of cases for which this technique is applied is expected to continue to grow. A further accumulation of cases is necessary to obtain high-quality evidence on the safety and efficacy of this surgical approach.