A rare case of duodenal inversum- A laparoscopically manageable entity.

Duodenal inversum is a rare disease not frequently encountered in clinical practice. The diagnosis is usually made late due to its rarity. Many other causes of abdominal pain like ulcer disease, pancreatitis, malrotation are mostly thought of initially and the diagnosis is usually missed. Only a few cases of duodenal inversum present with outlet obstruction. Duodenojejunostomy is perhaps the ideal management for duodenal inversum if the patient presents with outlet obstruction. Our intention is to create awareness of such a rare disease with an available definitive treatment option in the form of minimally invasive surgery. One such case of a 31-year-old man is described that was successfully managed by laparoscopic duodenojejunostomy.

Introduction

Duodenal inversum, a rare entity is usually diagnosed very late because it is not known to many that such a problem exists. It can have variable clinical presentation and can easily be overlooked.[1] Our intention is to create awareness about this rare entity and the feasibility of treating it effectively by laparoscopic method.

Case Report

A 31-year-old man with no comorbidities or previous surgeries, presented with complaints of recurrent bilious vomiting for 3 years, predominantly half to one hour after food intake. He also had symptoms suggestive of regurgitation for which he was on antacid drugs and prokinetics for several months. Further, he had lost weight; from 69 to 47 kg in 3 years.

Upper gastrointestinal endoscopy was suggestive of Los Angeles grade A distal esophagitis, antral gastritis and erosions in the first part of duodenum. Barium meal follow through showed dilated first part of duodenum and abnormal course of third part of duodenum, ascending superiorly towards the pylorus before crossing the midline to reach the duodenojejunal (DJ) flexure. The abnormal course of duodenum was also confirmed on contrast-enhanced computerized tomography (CT) abdomen scan [Figure 1]. Meanwhile after literature search, the entity of duodenal inversum was diagnosed. In view of persistent symptoms of outflow obstruction associated with weight loss surgical correction was planned for the condition.

Figure 1

(a) barium meal; and (b) sagittal section of contrast-enhanced CT scan of the abdomen (b) showing the abnormal course of the duodenum (arrows) typical of duodenal inversum [D2 and D3 = second and third part of duodenum, respectively]

Operative procedure

The patient was placed supine with leg split and 30-degree reverse Trendelenburg position. A 10 mm umbilical camera port was used. The right-hand working port was a 5 mm port placed in the left mid clavicular line below the subcostal margin. The left-hand working port was a 12 mm port in the right mid clavicular line below the costal margin which was also used for firing the endo GIA stapler. A 5 mm subxiphoid port was used for liver retraction while another 5 mm port at left anterior axillary line was utilized for gastric retraction. Mobilization of the hepatic flexure of the colon exposed the abnormal anatomy of duodenum with the third part running superiorly and posteriorly before crossing the midline to reach the ligament of Treitz in the left, typical of duodenal inversum [Figure 2].

Figure 2

(a,b) intra-operative view of the abnormal course of the duodenum (blue dashed line and arrows); (c) after complete Kocherization of the duodenum; (d) firing of linear endo GIA stapler between duodenum and jejunum; (e) closure of staple enterotomy site with PDS 3-0 running sutures. Ampulla can be seen (arrow); (f) completion of enterotomy closure. d [D1, D2, and D3 = first, second and third part of duodenum, respectively]

First and second parts of the duodenum were found to be dilated. Complete kocherization of the duodenum was done which did not correct the abnormal duodenal turn. A loop of jejunum 20 cm distal to duodenojejunal flexure was brought in retro-colic fashion and a side-to-side stapled duodenojejunostomy was done using 60 mm blue endo GIA stapler (Ethicon, USA). The staple enterotomy site was closed intracorporeally with PDS 2-0 sutures in continuous fashion. The mesenteric window was closed with PDS 2-0 interrupted sutures. Patient had an uneventful post-operative period. At follow up of six months he remains asymptomatic and has gained 8 kg. in weight.

Discussion

Duodenal inversum or inverted duodenum or figure of eight duodenum does not refer to situs inversus but rather an entirely different entity. In duodenal inversum, the third or horizontal part of duodenum takes a different course by ascending behind the descending segment after a spiral constriction and crosses the midline high up above the head of pancreas to reach the DJ flexure in the left.[2] The cause of duodenal inversum is unknown but failure of the dorsal mesentery to disappear leading to a mobile duodenum has been suggested as the possible underlying etiology.[2] Though it is not a rotational anomaly, duodenal inversum can be associated with malrotation of the gut. It can be confused with redundancy of first part of duodenum, malrotation, left sided duodenum of situs inversus and superior mesenteric artery (SMA) syndrome.

The age at presentation as well as the presenting symptom can be highly variable. Clinically it may be asymptomatic or present with symptoms of dyspepsia to even outlet obstruction. It might be associated with diarrhoea or gallbladder disease occasionally.[2345] The condition is often overlooked due to the overlapping symptomatology with more common clinical conditions as well as due to the rarity of the condition and lack of awareness among surgeons. Diagnosis is made on UGI series with barium contrast which shows the characteristic appearance of passage of contrast superiorly in the third part of the duodenum behind the second part before crossing the midline to reach the DJ flexure.[2] In patients with features of gastric outlet obstruction, the absence of findings consistent with the other more common etiologies and a normal anatomical location of DJ flexure should raise the suspicion of a duodenal inversum. In such cases the course of the duodenum should be carefully evaluated to avoid missing the diagnosis of duodenal inversum.

Management in the literature is varied from medical management to adhesiolysis to gastrojejunostomy or duodenojejunostomy.[2345] Usually these patients are prescribed acid suppressing and prokinetic drugs due to gastric, biliary and pancreatic juice induced inflammatory damage. Dogan et al.,[6] reported a case of duodenal inversum that was managed successfully with proton pump inhibitor (PPI) therapy. Medical management is a viable option in patients who do not have associated duodenal obstruction. Goyal et al.,[7] successfully managed a case of duodenal inversum with dietary modifications and prokinetics. Menchise et al.,[3] reported a pediatric case of duodenal inversum that they managed conservatively using prolonged enteral feeding. They used nasojejunal tube feeds for two months and then nasogastric tube feed for one more month before resuming full oral diet. However, prolonged nasoenteric tube feeding is often poorly tolerated by patients and does not provide a definitive solution to the problem.

Surgery is warranted if duodenal obstruction is present. We did a loop duodenojejunostomy, as it is more physiological than a gastrojejunostomy, as well as much simpler than a Roux-en-Y reconstruction. A side-to-side duodenojejunostomy was performed distal to an intact pylorus. Chandan et al.,[5] have also reported a case of duodenal inversum that was managed by end to side duodenojejunostomy. To the best of our knowledge, the present case is the first to undergo laparoscopic duodenojejunostomy for duodenal inversum. Though the follow-up has been only for six months, complete elimination of symptoms and progressive weight gain seen in our patient suggests that laparoscopic duodenojejunostomy is an effective form of treatment for duodenal inversum patients presenting with obstruction. High index of suspicion and early diagnosis is the key to success in preventing treatment delays and alleviating patient sufferings.

Conclusion

Though duodenal inversum is an uncommon cause of duodenal obstruction, making a prompt diagnosis is crucial as it can effectively be treated by laparoscopic intervention.

Declaration of patient consent

The authors certify that appropriate patient consent was obtained.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.