Primary necrosis of the round ligament in adults: A new case and literature review

Introduction: The necrosis of the round ligament is an exceptional entity. The clinical presentation is nonspecific and can lead us to call to mind other diseases. The diagnosis is suspected by an abdominal ultrasound and CT scan showing lesions between the liver and the abdominal wall with fat density that extends to the umbilicus. It is confirmed by the surgical exploration of the abdomen performed by classical or laparoscopic approach. Case Report: We are reporting the 16th case of this entity which presents a 56-year-old women who presented with right upper quadrant pain. The diagnosis of round ligament necrosis was suspected on abdominal ultrasound and the CT scan findings. It was then confirmed by laparoscopy which showed a gangrene of the round ligament. Conclusion: Primary necrosis of the round ligament of the liver is an extremely rare cause of acute abdominal pain. The diagnosis is tricky in spite of the contribution of the abdominal CT scan. The treatment is surgical.


INTRODUCTION
The round ligament is a fibrous remnant of the fetal umbilical vein. It stretches from the left part of the liver to the anterior abdominal wall. In adults, it can exceptionally form a gangrene and present with an acute abdomen. The underlying pathology is a primary ischemic necrosis of the connective tissue causing an inflammatory response in the peritoneal cavity. The subsequent translocation of enteric bacteria through the intestinal wall gives rise to diffuse infectious peritonitis. No triggering factor has been identified. Clinically, patients present with nonspecific peritoneal irritation signs. The diagnostic challenge has been overcome thanks to the contribution of the CT scan which demonstrates a necrotic mass between the liver and the abdominal wall.
In this article, we have compiled 15 cases from bibliographic search. We were able to access the medical observation details in 14 of them. We also report a new case diagnosed in Tunisia; the 16th in the world-review of literature.
This work has been reported in line with the SCARE criteria [1].

CASE REPORT
A 56-year-old woman with a history of high blood pressure presented to the emergency department complaining of right upper quadrant pain over the past week. Physical examination showed a temperature of 38°C and guarding of the right upper quadrant. Laboratory results showed WBC of 13100/mm 3 , HB of 9,8 g/dl, the rest was normal.
Abdominal ultrasound showed an oblong hyperechoic mass between the 3 rd and 4 th hepatic segments and a gallstone. A CT scan was performed. It showed infiltration and thickening of the round ligament and a cholecystitis (Figure 1). The patient was operated on by laparoscopy. Intra-operatively we discovered an inflammatory cholecystitis and a gangrene of the round ligament ( Figure 2). A cholecystectomy and a total removal of the round ligament were performed with sub-hepatic drainage. Follow-ups were simple and complication-free. The patient was discharged from the hospital six days after the surgery. The anatomic pathology examination was in favor of an abscess of the round ligament.

DISCUSSION
The primary necrosis of the round ligament is an exceptional entity. The preoperative diagnosis is difficult due to the lack of specific signs. The symptoms consist of abdominal pain, vomiting, nausea and fever. It can mislead us to think of other diseases such as cholecystitis [2], pancreatitis [3] and a perforated ulcer [4]. The pathophysiology is still uncertain. Two theories have been developed; The first considers the origin to be infectious with a starting point in the umbilicus [5]; The second considers the origin to be ischemic similar to appendicitis [6]. The first theory is more likely in the case of our patient because of the association with a cholecystitis. The ultrasound can show a heterogeneous hyperechoic mass between the liver and the anterior abdominal wall which is variable in size. The CT scan is more accurate and specific but the interpretation of morphological data can be distorted due to the lack of knowledge of the disease. The treatment of primary necrosis of the round ligament is surgical involving a resection of the ligament at variable levels and a potential drainage. Some authors suggest a medical treatment if the diagnosis is uncertain [7]. Through a systematic review of literature, we have compiled only 15 cases (Table 1) [8][9][10][11][12][13][14][15][16][17][18][19][20].
After analyzing the data from literature,we have concluded that, like in our case, this disease affects mostly women (10 women) with ages varying between 18 and 86 years old. In all the cases reported, the clinical presentation was an acute abdomen that evoked at first other diagnoses. The Ultrasound and CT scan showed pathognomonic signs which are of a heterogeneous and hyperechoic mass with fat density situated between the   liver and the umbilicus. The abdominal CT scan seems to be the standard imaging technique to diagnose of this entity. The treatment was surgical in all reported cases. The laparoscopy was used five times including our case.

CONCLUSION
The primary necrosis of the round ligament is an exceptional cause of acute abdomen. Preoperative diagnosis is difficult to establish but it can be evoked based on many imaging data. Surgery allows the confirmation of diagnosis and the treatment especially laparoscopy which has many advantages.

Guarantor of Submission
The corresponding author is the guarantor of submission.