Primitive Internal Hernia in Adult: A Report on 6 Cases

Internal hernia is defined as the protrusion of an abdominal organ through a peritoneal or mesenteric aperture. It is a rare cause of small bowel obstruction. The incidence of these hernias is estimated at between 0,2 and 2% of abdominal hernias, and o.2% to 0.9% of autopsies [1,2]. It can be primitive or secondary to an abdominal intervention. Internal hernias are classified based on the location of the potential defect. The aim of our study is to report 6 cases of primitive internal hernia, representing different anatomical types.


Introduction
Internal hernia is defined as the protrusion of an abdominal organ through a peritoneal or mesenteric aperture. It is a rare cause of small bowel obstruction. The incidence of these hernias is estimated at between 0,2 and 2% of abdominal hernias, and o.2% to 0.9% of autopsies [1,2]. It can be primitive or secondary to an abdominal intervention. Internal hernias are classified based on the location of the potential defect. The aim of our study is to report 6 cases of primitive internal hernia, representing different anatomical types.

Patients and Methods
Six patients of a mean age of 31,7 years (range 24-75) were admitted to our department of general surgery, at Mohamed VI university hospital of Marrakech (Morocco), on emergency during a period of six years (from 2006 to 2011). We reported 3 males and 3 females. All patients denied any surgery or intra-abdominal inflammatory process.
We reviewed the patient's records, imaging modalities and operative findings of these cases.
All patients were operated.

Results
All patients consulted on emergency. Table 1 shows the presenting symptoms of our patients. Acute intestinal obstruction was found in 4 cases (66%). Other abdominal symptoms were found: abdominal pain (n=6), nausea (n=2), vomiting (n=5). The interval between the beginning of symptoms and hospitalization ranged from 24 to 72 hours (mean: 52 hours). The physical exam revealed abdominal distention in 4 patients (66%), abdominal tenderness in 2 patients (33%), and fever and peritonitis in three patients (50%). One patient presented a septic shock.
Abdominal X-ray showed air fluid levels in four patients (66%). Ultra sonography examination showed peritoneal fluid in also four patients. CT scan was done in four patients on emergency.
It suggested non specific internal herniation in two patients. In the other two patients, it suggested a specific internal herniation: a paraduodenal hernia in a case and a gastric herniation in the other case ( Figure 1 ¾ The surgical treatment for those different types of hernias is explained in Table 2.
¾ Small bowel resection was done in two patients.
We had no death in our six patients. Two cases of wound infection were reported classified Grade I in the Clavien-Dindo classification of surgical complications. These patients were treated by antibiotics aperture. Internal abdominal herniations can be either acquired through a trauma or surgical procedure (iatrogenic internal abdominal herniations) or constitutional, related to congenital peritoneal defects [2,3]. In the broad category of internal hernias are several main types, as traditionally described by Meyers [4], based on location.
In literature, there are many types of primitive internal types, as traditionally described by Meyers [4], based on location.
In literature, series reporting primitive internal hernias (PIH) are rare. PIH have no sex predilection as in our series (3 males, 3 females) [4]. The patients in our series were very young (mean age: 31.7 years) comparing to other series: Gullino and al (45 years), Armstrong and al (71 years) and Akyildiz and al (50 years) [1,5,6].
There is no specific symptom for PIH. Abdominal pain and acute small bowel obstruction are the most common presentation as in our cases. Other symptoms have been reported as intermittent bowel obstruction, peritonitis (in three of our cases), fever, nausea, vomiting and sepsis [2]. Symptom severity relates to the duration and reducibility of the hernia and the presence or absence of incarceration and strangulation [6].  (Ciprofloxacin 500 mg/ two times a day for 5 days) and had local treatment. The length of hospital stay was 6.4 days (3 -10 days).

Discussion
An internal abdominal herniation is the protrusion of an abdominal organ through a normal or abnormal mesenteric or peritoneal

Type of primitive hernia Number of cases treatment
Left para duodenal hernia 2 Closure of the defect,Small bowel resection: one cases  Imaging studies often play an important role in the diagnosis of internal hernias because of the non specificity of clinical signs. CT is the first-line imaging technique in these patients because of its availability, speed, and multiplanar reformatting capabilities. CT could show the hernia sac and its anatomic relationship to the surrounding organs and vasculature. It can also find mesenteric vessel abnormalities, with engorgement, crowding, twisting, and stretching of these vessels commonly found and providing an important clue to the underlying diagnosis [7][8][9]. In our series, it showed no specific signs suggesting internal hernia in two cases, but in the other two cases, it confirmed the exact type of the hernia.
The treatment of these herniations depends on the surgical findings. In the absence of necrosis, it consists of a reduction of the hernia, with closure of the defect when it is possible.
This procedure can be done by laparoscopy or laparotomy, depending of the patients and the experience of the surgeon [3,6].
Approximately 50% of the patients developed morbidity after surgical procedures. Age, delayed laparotomy time (>3 days after the onset of the symptoms) and the presence of a comorbidity were related to morbidity [10,11].

Conclusion
Primitive internal herniation remains a rare cause of consultation on emergency. It must be evocated in patients with no medical history and consulting for acute intestinal obstruction. CT scan suggests often the diagnosis that is confirmed at surgical exploration. The treatment is always surgery.