Pancreaticoduodenectomy with malrotation following reoperation due to torsion of efferent loop: a case report

Background Malrotation is a congenital anomaly during the development of the embryonic intestine. Although it is generally considered a pediatric surgical condition, it can have significant implications for adult surgery in terms of reconstruction. Case presentation The patient was an 85-year-old man with pancreatic cancer and intestinal malrotation. He underwent pancreaticoduodenectomy with modified Child’s reconstruction. Because the ascending colon and efferent loop twisted easily, we fixed the ascending colon to the abdominal wall. Thereafter, right twist and stenosis of the efferent loop occurred. On the 22nd day after the initial surgery, detorsion and Braun anastomosis were performed for efferent loop fixation. Postoperative oral intake was good, and the patient was discharged from our hospital on the 24th day after the reoperation. Conclusions This is a rare case of pancreaticoduodenectomy with malrotation following reoperation due to a complication after Child’s reconstruction. In similar cases of intestinal malrotation, it is important to consider avoiding coaxial positioning of intestinal parts and an upper abdominal space while selecting a reconstruction method.


Background
Intestinal malrotation is a developmental anomaly of the embryonic intestine, which is frequently observed in neonates. Although it occurs rarely in adults, it influences the condition of the intestines and has significant implications for reconstruction surgery. Here, we present the case of a patient who underwent pancreaticoduodenectomy and had intestinal malrotation following reoperation due to torsion of the efferent loop.

Case presentation
The patient was an 85-year-old man who presented with appetite loss and choluria. His past medical history included hypertension, tuberculosis, and ulcerative colitis. Laboratory examination revealed elevated hepatobiliary enzyme and serum tumor marker levels: total bilirubin, 21.2 (normal range, 0.1-1.2) mg/dL; aspartate aminotransferase, 83 (normal range, 5-30) IU/L; alanine aminotransferase, 103 (normal range, 3-35) IU/L; alkaline phosphatase, 1699 (normal range, 90-300) IU/L; γ-glutamyl transpeptidase, 926 (normal range, 1-28) IU/L, carcinoembryonic antigen, 5.9 (normal range, 0-5) ng/mL; carbohydrate antigen 1966 (normal range, 0-37) ng/mL, and s-pancreas-1 antigen, 371.5 (normal range, 0-30) U/mL. Computed tomography revealed a low-density pancreatic head mass (diameter: 25 mm) and dilation of the common bile duct and pancreatic Open Access *Correspondence: twiddle_r@yahoo.co.jp Department of Surgery, Kasugai Municipal Hospital, 1-1-1 Takaki-cho, Kasugai-shi, Aichi, Japan duct. The superior mesenteric vein (SMV) was located to the left of the superior mesenteric artery, and this phenomenon is known as the SMV rotation sign (Fig. 1a). The duodenal sweep did not cross the midline, the small bowel was located in the right abdomen, and the large bowel was located in the left abdomen (Fig. 1b). These findings are consistent with the characteristics of malrotation. Endoscopic retrograde cholangiopancreatography revealed interruptions in the continuity of the common bile duct and main pancreatic duct, and brush cytology showed pseudo-positive findings. Based on these findings, the patient was diagnosed with pancreatic cancer accompanied by malrotation. During laparotomy, we noticed that the ligament of Treitz was absent, the small bowel was in the right abdomen, and the ascending colon and cecum were not fixed to the retroperitoneum but were located in the median abdomen (Fig. 2a). These findings indicated the nonrotation-type malrotation. Fig. 1 Computed tomography findings. a A 25-mm low-density mass located in the pancreatic head (arrowhead). The superior mesenteric vein (SMV) was located to the left of the superior mesenteric artery, showing the SMV rotation sign (arrow). b The small bowel was located in the right abdomen, and the large bowel was located in the left abdomen Fig. 2 Findings in the initial operation. a The ligament of Treitz was absent, and the small bowel was in the right abdomen. Further, the ascending colon and cecum were not fixed to the retroperitoneum but were located in the median abdomen. AC, ascending colon; P, pancreas; St, stomach; SMA/V, superior mesenteric artery and superior mesenteric vein. b Pancreaticoduodenectomy with reconstruction using the modified Child's method was performed. We fixed the ascending colon to the abdominal wall because the ascending colon and efferent loop twisted easily (arrow) Pancreaticoduodenectomy with reconstruction using the modified Child's method was performed. In addition, we fixed the ascending colon to the abdominal wall because the ascending colon and efferent loop twisted easily (Fig. 2b). The pathological diagnosis was as follows: tubular adenocarcinoma, moderately differentiated, and pT2N1M0 Stage IIB in accordance with the eighth edition of the UICC TNM Classification.
On postoperative 4th day, upper gastrointestinal (UGI) series showed that contrast medium easily flowed through the intestines (Fig. 3a), and the patient was prescribed a postoperative diet. On postoperative 8th day, the patient vomited and UGI series showed that contrast medium did not flow into the efferent loop (Fig. 3b). On postoperative 12th day, upper endoscopy revealed anastomotic edema and stricture; however, contrast medium flowed into the efferent loop (Fig. 3c). Although we treated the patient conservatively, he did not respond to the treatment. On postoperative 20th day, the upper endoscope could not pass through the anastomotic site and UGI series revealed right efferent loop twisting (Fig. 3d). On postoperative 22nd day, reoperation was performed. During laparotomy, it was found that the efferent loop had twisted 180° in the clockwise direction and was adherent to the right upper abdominal wall (Fig. 4a). Detorsion and Braun anastomosis were performed to prevent torsion and maintain the efferent loop continuity inferiorly (Fig. 4b). Postoperative oral intake was good, and the patient was discharged from our hospital on the 24th day after reoperation.

Discussion
Intestinal malrotation is a congenital anomaly, with 80% of cases occurring in neonates [1]. The remaining cases are not diagnosed until adulthood and often show asymptomatic incidental findings [2].
When performing pancreaticoduodenectomy in patients with malrotation, factors such as intestine position, vascular anomalies, and reconstruction procedures should be considered. The Ladd procedure has traditionally been performed to treat malrotation, and it entails division of Ladd's bands, detorsion of the volvulus, and reorientation of the small bowel in the right intestine and the colon in the left intestine [4]. In cases associated with malignancy, it is important to choose an appropriate reconstruction procedure in addition to treatment for intestinal malrotation. However, no report on the reconstruction procedure was found. We conducted a review of literature that included Japanese studies by searching the PubMed database, and we found reports on a total of 16 patients with intestinal malrotation who underwent pancreaticoduodenectomy (Table 1) [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. None of the 16 patients developed any complication associated with reconstruction.
Kawano et al. [20] reported that a patient with intestinal malrotation required reoperation for reflux esophagitis followed by total gastrectomy with Billroth II reconstruction. In their patient, the lifted jejunum released into the left upper abdomen because the intestines were not adequately fixed to the retroperitoneum. Roux-en-Y anastomosis and intestinal fixation were performed during the reoperation, and the necessity of intestinal fixation was explained. In contrast, Stauffer et al. [21] reported that additional fixation was unnecessary.
There were two complications of child's reconstruction in our patient. First, there was a risk of detorsion of the volvulus given that the ascending colon was adjacent and positioned coaxially to the efferent loop. We prevented its torsion by additionally fixing the ascending colon to the abdominal wall. However, reconstruction may best Fig. 4 Findings of the reoperation. a After detorsion, the efferent loop had twisted 180° in the clockwise direction and was adherent to the right upper abdominal wall (black arrow). b Braun anastomosis was performed to prevent efferent loop twisting and maintain its continuity inferiorly. A, afferent loop; E, efferent loop; St, stomach be performed using the Cattell's approach or Imanaga's method, particularly in cases such as our case, because the ascending colon cannot be positioned coaxially to the efferent loop in these methods. Second, there was a space in the right upper abdomen that the efferent loop easily entered. We usually do not perform Braun anastomosis along with pancreaticoduodenectomy because we believe that Braun anastomosis is not necessary in all cases. In the present case, although Braun anastomosis was useful in the stabilization of the efferent loop, the large space in the upper abdomen could have been avoided if reconstruction was performed using Cattell's approach or Imanaga's method. These methods might be useful in the cases of nonrotation-type intestinal malrotation or some cases of reversed rotation-type intestinal malrotation; however, a definite recommendation cannot be given considering the different types of anomalies. In addition, Braun anastomosis or intestinal fixation should be considered.

Conclusions
We presented a rare case of pancreaticoduodenectomy with malrotation following reoperation due to a complication of a surgical method. Coaxial positioning of intestinal parts and an upper abdominal space should be avoided in patients with intestinal malrotation who undergo gastrointestinal tract reconstruction.