Laparoscopic reduction and repair of a left paraduodenal hernia

Abstract

Left paraduodenal hernias are the most common type of congenital internal hernia, but they are difficult to diagnose without appropriate imaging. A 79-year-old man with a history of recurrent abdominal pain had another similar episode of abdominal pain, which prompted him to seek evaluation. The pain resolved spontaneously on arrival to the hospital. Enhanced CT scan showed the characteristic findings of a left paraduodenal hernia and laparoscopic repair was undertaken. The small intestine was reduced successfully, and the hernia orifice was approximated with a continuous closure. He was discharged uneventfully 4 days after admission. The characteristic clinical and imaging findings of paraduodenal hernias are reviewed. Laparoscopic repair is reasonable in patients who have a paraduodenal hernia without intestinal ischemia.

Background

Internal hernia is a protrusion of abdominal viscera through congenital or acquired orifices inside the abdominal cavity. Paraduodenal hernias are the most common congenital hernia (53%), followed by paracecal (13%), foramen of Winslow (8%), trans-mesenteric (8%), sigmoid mesocolon (6%), pelvic or supravesicular (6%) and trans-omental hernia (1%–4%).¹ Paraduodenal hernias are classified into right-sided or left-sided hernias with left-sided being more common.² Laparoscopic reduction and repair of left paraduodenal hernias have been reported. Some studies demonstrated the efficacy and safety of this approach but the conversion rate to open surgery was as high as 27% because of technical difficulties.²

Understanding the anatomical imaging and operative view of a paraduodenal hernia is important for every general surgeon. We present a patient with a left paraduodenal hernia with successful laparoscopic reduction and closure with imaging studies and an operative video.

Case presentation

The patient is a 79-year-old man with a history of open appendectomy, who presented with acute onset of continuous abdominal pain. He had similar pain three or four times a year over the last 5 years, which necessitated admission to the hospital and spontaneously resolved each time. There was no specific aetiology identified for the pain.

Following admission, his abdominal pain again resolved spontaneously. Physical examination showed mild tenderness in the left upper quadrant without peritoneal signs. He did not vomit and had a bowel movement after the onset of the pain. Laboratory studies were within normal limits. Abdominal CT scan showed typical of a left paraduodenal hernia. The herniated small bowel was behind the inferior mesenteric vein (IMV), which entered the sac to the left of the IMV (figure 1). A left paraduodenal hernia without strangulation was diagnosed and laparoscopic reduction and repair of the hernia was performed the following day.

Figure 1.

(A) Inferior mesenteric vein (white arrow) was seen anterior to the small intestine. (B) White arrow heads show the incarcerated bowel.

Treatment

An umbilical port was placed followed by two 5 mm ports in the right upper quadrant. A 25–30 mm defect was noted to the right of the IMV, known as the Landert fossa and 60–80 cm of herniated small intestine was reduced without difficulty. We did not resect the bowel because there were no ischaemic changes, consistent with the physical examination. There were fibrous changes at the hernia orifice (figure 2A). The hernia was closed with 3–0 absorbable sutures, being careful to avoid injury to the IMV (figure 2B).

Figure 2.

Intraoperative findings of left paraduodenal hernia. (A) Before reduction, the black arrows show the inferior mesenteric vein (at the hernia orifice). (B) After repair of the hernia, black arrows show the approximated hernia orifice.

Outcome and follow-up

The patient began oral intake on the first postoperative day. There was no abdominal pain after surgery and he had a bowel movement on the second postoperative day. He was discharged on the fourth postoperative day without complications.

Discussion

Internal hernias rarely cause acute abdominal conditions needing emergent surgery. Paraduodenal hernias are the most common type of internal hernia, accounting for approximately 53% of all cases of internal hernia.¹ Paraduodenal hernia, also called Treitz’s hernia, is categorised into either left-sided or right-sided based on the location of the hernia relative to the ligament of Treitz. A left paraduodenal hernia results in herniation into Landart’s fossa. This fossa, present in about 2% of autopsy cases, is situated some distance to the left by the inferior mesenteric vein as it runs along the lateral side of the fossa and then superior to it. The free edge of the hernia thus contains the inferior mesenteric vein and the ascending left colic artery.³

Clinical features are variable, ranging from mild abdominal cramps to symptoms of acute obstruction with diffuse abdominal pain. Classically, a paraduodenal hernia may cause postprandial abdominal pain.^{4 5} The typical features on abdominal CT scan include an abnormal cluster or sac-like mass of dilated loops of small bowel between the pancreas and stomach to the left of the ligament of Treitz.⁵ Identification of small bowel beneath the IMV is a critical finding in patients with a left paraduodenal hernia.

The principles of surgical management include reduction of the herniated bowel, resection of any necrotic intestine and closure of the hernia orifice. Traditionally, repair of a left paraduodenal hernia is performed by open surgery. The first laparoscopic repair was reported by Uematsu et al in 1998.⁶ If the diagnosis is not definitively established before exploration, laparoscopic exploration may be useful. In most patients, a paraduodenal hernia has characteristic findings on CT scan. The preoperative diagnosis should be established whenever possible.

In the present patient, the initial diagnosis was a small bowel obstruction due to adhesions after appendectomy, but the preoperative CT scan established the diagnosis of a left paraduodenal hernia. The small intestine was noted to be beneath the IMV on CT scan. Though paraduodenal hernias are rare and can be difficult to diagnose, it must be considered in the differential diagnosis of a patient with a history of crampy abdominal pain, especially patients without a prior laparotomy. In addition, surgeons must have in mind a detailed image of the anatomy of potential internal hernia orifices to diagnose a paraduodenal hernia accurately.

A review of paraduodenal hernias concluded that the laparoscopic approach is associated with lower morbidity and a shorter hospital stay than open surgery, although there may be some selection bias for the type of surgery.² It is reasonable to convert to open surgery in patients with bowel necrosis requiring resection. In the systematic review, however, the conversion rate was as high as 24.3% although bowel resection was performed only in 12.6% of patients with a left paraduodenal hernia.² The difference may reflect the difficulty of laparoscopic treatment of left paraduodenal hernias.

We closed the hernia orifice with a continuous suture between the jejunum near the ligament of Treitz and the sheath of IMV, and between the mesentery of the jejunum and the sheath of IMV. In most previous reports, the hernia orifice was approximated with sutures.⁷ Obviously, care must be taken not to injure the IMV during the closure. IMV injury and ligation were reported in a case report.⁸ Recurrence of a paraduodenal hernia was reported 18 months after the original repair and the recurrent hernia was repaired with Gore-Tex.⁸ In some case reports, the hernia sac was everted.⁷ It is not imperative to excise the hernia sac and we did not evert the hernia sac in the present patient. Laparoscopic management of left paraduodenal hernias is gaining popularity, but this requires training in advanced laparoscopic techniques.

Learning points.

• Understanding the anatomical imaging and operative view of a paraduodenal hernia is important for every general surgeon.

• Identification of the small intestine beneath the inferior mesenteric vein on CT scan is a critical finding in patients with a left paraduodenal hernia.

• Laparoscopic management of left paraduodenal hernias is gaining popularity, but this requires training in advanced laparoscopic techniques.