Hydatid cyst disease is caused by E. Granulosus and less frequently with E. Multilocularis (1, 2). Tunisia is an endemic country of hydatid cyst of the liver (1). Although commonly considered "benign," this disease continues to have devastating impact on people’s health due to its potentially serious related-complications, especially the rupture. Three types of ruptures have been described: “contained rupture” where the ruptured cyst remains surrounded and contained by the adjacent hepatic parenchyma, “communicating rupture” with a bile or vascular duct and the “direct or free rupture” which occurs to the peritoneal cavity (3, 4). Intraperitoneal Cystic rupture is a rare complication of hydatid disease and occurs in 1–16% of reported cases (2, 5, 6). These results corroborate with data in the current series showing that its prevalence is estimated at 2.4%. Intraperitoneal cyst rupture can take place spontaneously, and it may be explained in this case by an increase in the intra-cystic pressure (7). It may also be caused iatrogenically during intra-operative manipulation as a result of accidental injury, or by an abdominal trauma (8, 9). The three leading incriminated factors in intraperitoneal cyst rupture are: The young age of the patients, as shown in this series (mean age 38 years) and it has a direct relationship with the activity (4, 9), the increase in cyst diameter above 10 cm and the superficial location unprotected by covering liver tissue (9, 10).
The clinical features vary greatly, from a completely asymptomatic form discovered late after secondary peritoneal hydatidosis to the authentic anaphylactic shock, which can immediately endanger the patient's life (8). It is often a sharp pain in the right upper abdominal quadrant associated with nausea and vomiting (9). Clinical examination typically reveals tenderness in the right upper abdominal quadrant and in a number of cases diffuse abdominal tenderness. In the current series, five patients had diffuse abdominal tenderness. Peritoneal signs and symptoms may develop earlier and can be more severe if bile leakage occurs or the cyst is infected (11, 12). Isolated cutaneous allergic symptoms, such as urticaria, macular eruption and pruritus, may occur in 16–25% of cases and indicate a minimal allergic reaction developed against the cystic content spilled into the abdominal cavity (13). The clinical presentation of intraperitoneal rupture of hydatid cyst is strongly related to the rupture size and the aspects of the cysts content (4). There are two distinct forms of Hydatid cyst rupture to the peritoneal cavity, the small fissuring which is the most common form, usually induced by a minimal neglected trauma and the large authentic rupture, which often takes place following a severe trauma (7). The minor fissuring results in cutaneous allergic reaction, the small amount of hydatid liquid spilled in the peritoneal cavity may either encyst or result in a military hydatid form. The large rupture is rare and may cause a real acute form leading to immediate fatal anaphylaxis choc (7). Anaphylactic shock incidence rate is approximately 1.4% (9). Severe allergic reactions such as dyspnoea, syncope and circulatory collapse occur in 1%-12.5% of cases (14). In our study, severe allergic reactions were reported in 6,6%. Either way, nonspecific misleading clinical presentation should not be a cause of diagnostic delay as the latter is a critical risk factor accounting for poor prognosis.
Hydatid serology associated with imaging modalities instead play a key role in establishing the diagnosis (3, 15). Ultrasound is the first examination of choice (1). It allows detection of the cysts as well as their precise staging according to Gharbi classification (16) with a sensitivity of 85% (9). It also helps to suspect the rupture of the cyst by showing a floating membrane with intraperitoneal fluid (7, 10). However, CT with a sensitivity of 100% and high-resolution multiplanar reconstruction images is a more powerful tool that provides an accurate assessment of the cyst, its exact location, its vascular and biliary connexions and detects any other concomitant cysts in the abdomen (1, 3, 11). It confirms rupture by showing a collapsed cyst wall with a reduced cyst size compared to former CT findings, a detached membrane, a discontinuity in the cyst wall, or daughter cysts and fluid in the peritoneal cavity (7). In our series, CT scan allowed establishing the diagnosis in all cases. However, its main constraining factor remains the requirement of patient’s hemodynamic stability.
Patient’s prompt management must begin in the emergency room. Close monitoring associated with compulsory intensive care measures, the use of vasoactive drugs if needed, antihistamine medication and corticosteroids are the first rescue measures to be taken in the emergency room (8). Urgent surgery should be considered. It has two basic goals: to treat the primary liver hydatid cyst and to treat its complication in order to prevent local and peritoneal recurrences (4, 13). Approaches of surgical treatment of the primary liver cyst can be divided into the unroofing procedure, which is a conservative modality and radical methods that include pericystectomy, pericystoresection and hepatectomy (1). In this emergency context, the conservative procedures seems to be the method of choice, since It does not require very high surgical skills, poses a negligible risk of bleeding, shortens the operative time (12, 17). Moreover, the unroofing prevents the morbidity of more invasive methods that would be less tolerable especially by a patients already weakened by anaphylaxis (1). The Zero mortality rate and low specific postoperative morbidity (6.66%) in our series strongly argues in favour of this technique. The second pillar of the surgical treatment is a large volume intraoperative lavage (5). Hypertonic saline solution (3%-30%) is the widely used solution in this purpose (10, 13, 17). Some authors choose not to use hypertonic saline solution due to its possible complications, such as hypernatremia (1, 18). This scolicidal solution was safely used in all cases in our study. Other experimental studies even advocate the use of povidone-iodine as a solution with a better scolicid potential (5, 13). The aim of this surgical step is to put an end to the contact between the peritoneum and the hydatid antigens causing the allergic reaction and to remove all cyst contents especially the protoscolex, source of late disseminated recurrence (4, 8, 9). In case of large cysts greater than 10.5 cm in diameter and / or with bilious content and / or in presence of clinical (cholestatic jaundice), biological (biological cholestasis) or radiological (bile ducts dilatation) signs of associated rupture into the bile ducts, intraoperative cholangiogram is indicated and fistula treatment is required (19–21). Anthelmintic treatment based on Albendazole (15 mg / kg / day) should be initiated as soon as possible after surgery (8). There is no consensus on how long to continue this treatment. Besides, several experimental studies have demonstrated the superiority of the combination of chemotherapy and cytokines over albendazole alone (22). In our center, a medical habit of maintaining Albendazole treatment for at least 12 months was respected in all patients. The effectiveness of this procedure is confirmed by the fact that no case of secondary peritoneal hydatidosis was observed in all patients of our series.
Considering the risk of recurrence, sometimes correlated to insufficient peritoneal lavage or medical treatment (6) patients with treated hydatid cysts should have appropriate follow up based on hydatid serology (indirect hemagglutination test) associated with abdominal ultrasound periodically conducted every 3 to 6 months. We estimate that those two methods combined allows recurrence to be early checked and acted upon. CT scan may be a part of the subsequent investigations in doubtful cases only to reduce patients’ exposure to radiation. Beyrouti et al reported a recurrence rate of 6,7% and a higher rate at 14% was reported by Sosuer et al (1). In the present series, no case of recurrence was detected with a median follow up period of 19 months.