Occult Intrabiliary Rupture of Hydatid Cysts in the Liver

Methods

A total of 324 patients with hydatid cyst of liver who were operated on in Ankara Numune Research and Training Hospital 6th Department of Surgery, during 1983-2003 were analyzed. Among them, 39 (12%) who were found to have occult intrabiliary rupture were included in this study. There were 20 male and 19 female patients with an average age of 38 years (15-68 years). The clinical symptomatology, physical examination, laboratory findings, results of imaging studies, localization of the cyst, size of the cyst, operative findings, and the effects of different surgical modalities on the hospital stay and morbidity were investigated. In all the patients, serum aminoospartate and alanine transaminasis, c-glutamie transaminase, alkaline phosphatase, and bilirubin levels were measured, to detect the presence of an infection within the cyst cavity, leukocyte counts, erythrocyte sedimentation rates, and Creactive proteins (CRP) levels were also measured. Computed tomography was performed in only five patients, in whom it was deemed necessary. The size of the cyst, its localization, and its cavitary appearance were evaluated by ultrasonographic examination.

The patients who were recruited were thought not to have biliary-cystic communication based on their clinical findings, laboratory results, and imaging studies; however, during the operation the presence of bile in the cyst and a visible internal opening of the biliary duct in the cavity at exploration were diagnosed as occult intrabiliary rupture and were further investigated. The patients who were diagnosed as having a frank intrabiliary rupture were excluded from the study. Although frank intrabiliary rupture was not their preoperative diagnosis, the patients who had widening of the common bile duct or who ended up having choledocotomy as a result of the size of the biliary duct that was opening into the cavity were not included in the study. Additionally, patients with infected hydatid cysts were not included.

For the statistical evaluation, the Mann-Whitney U-test was used for postoperative hospitalization. Fisher's exact test was used to evaluate the complication and biliary fistula rates. A value of p < 0.05 was accepted as statistically significant.

Results

The most commonly encountered symptom was right upper quadrant pain, which was present in 26 cases (67%). On physical examination, a right upper quadrant mass was detected in seven patients (18%); the other physical examination findings were normal. In all patients there were no laboratory finding that would make us consider obstructive jaundice or infected hydatid cyst: All laboratory tests were normal. The ultrasonographic examination provided no findings that would raise the suspicion of biliary-cystic communication.

Hydatid cysts were localized on the right liver lobe in 32 patients (82%), on both lobes in 6 patients (15%), and on the left lobe in 1 patient (3%). The most common site of localization was segments VII-VIII (67%). Hydatid cysts were smaller than 5 cm in 3 patients (8%), between 5 and 10 cm in 25 patients (64%), and larger than 10 cm in 11 patients (28%).

As an operative strategy, scolicidal agents were not used in patients who had bile aspirated during puncture of the cysts. In all the remaining patients, 20% hypertonic saline or 0.5% cetrimidechlorohexidine were injected into the cyst in volumes that were equal to that of the aspirate. The cyst was opened after waiting 10 minutes and its content emptied. And surgical intervention directed at the cavity was them initiated. In all patients in whom the opening of the biliary duct was identified, it was sutured with nonabsorbable suture material. The surgical technique to be utilized for the cavity was chosen after taking into consideration such factors as the localization and number of cysts, their size, the condition of the greater omentum, and the presence of intraabdominal adhesions.

As bile was present in the cyst aspirates of 27 patients (69%), scolicidal agents were not used for them. In 12 cases (31%) there was no bile in the aspirate; hypertonic saline was injected in 4 of them, and 0.5% cetrimide-chlorohexidine solution was utilized in 8 others. In 22 patients (56%) the opening of the biliary duct was identified and sutured. Partial cystectomy was performed in all 39 patients. In addition, cavitary drainage was performed in 23 (59%) patients; cavitary drainage was not performed in 16 others, and omentoplasty was undertaken (41%).

Altogether, 12 patients had complications (30%), but there was no mortality. The distribution of postoperative complications for both groups is given in Table 1 (p > 0.05). The most common complication was bile fistula. Bile fistulas were not observed in patients in whom omentoplasty was performed, but they were seen in six patients who underwent cavitary drainage (26%) (p = 0.06). All of these patients were cured after medical treatment, and the fistulas had closed at an average duration of 35 days (23-51 days). One patient who developed a subdiaphragmatic abscess was reoperated on the 44th postoperative day.

The average hospital stay was 7.0 AE 3.8 days (median AE standard error) for omentoplasty cases and 6.0 AE 2.5 days (median AE standard error) in patients with cavitary drainage. The difference was not statistically significant (p > 0.05).

Discussion

There is no consensus regarding the terminology to be used in hydatid cyst cases with biliary-cystic communication. The clinical picture of obstructive jaundice that develops after opening the hydatid cyst to the biliary ducts and passage of the cyst contents to the biliary system has been called intrabiliary rupture by several authors [7,9]. Zaouche et al. [2] used the term biliocystic fistula for the same clinical presentation. Becker et al. [6] and Dadoukis et al. [3] used the term intrabiliary rupture as a general definition for all the hydatid cysts that have communication with the biliary system without taking into consideration the severity of the clinical problem. These authors have classified biliary rupture into two groups: frank and occult ruptures. Taking the study of these authors into account, we used the term biliary-cystic communication without considering whether the patients had findings of obstructive jaundice.

On the other hand, patients with minimal or no clinical symptomatology who were not thought to have obstructive jaundice peroperatively, but who exhibited communication with biliary ducts preoperatively, were classified as having an occult intrabiliary rupture.

Although frank intrabiliary rupture generally is associated with abdominal pain, jaundice, fever, weakness, and cholangitis episodes, occult intrabiliary ruptures are usually clinically silent, although their most common symptom is abdominal pain [6][7][8]. In our series, the most commonly encountered symptom was abdominal pain, yet it was not definitive for a diagnosis of occult intrabiliary rupture. These patients have nonspecific physical examination findings that do not aid in the diagnosis. Although ultrasonography is a simple, reliable diagnostic tool for uncomplicated hydatid cysts of the liver, its accuracy rates are much lower for the diagnosis of intrabiliary rupture [6].

Hydatid cysts located on segment IV of the liver are at higher risk of developing biliary-cystic communication when compared to other localizations [10]. In this series, only 13% of the cysts were on segment IV. However, the size of the cyst is as important as its localization in the development of biliary-cystic communication; as the cyst grows, the elevated intracystic pressure augments the risk for the development of biliary-cystic communication [6,10].

Various scolicidal agents are being used to this end in uncomplicated cases; however, because there is a risk of sclerosing cholangitis, this approach is not recommended for patients who have a biliary-cystic connection [11,12]. As most frank intrabiliary ruptures are diagnosed during the preoperative period, scolicidal agents are not used in these cases. For occult intrabiliary ruptures, if there is no bile-stained cystic fluid, scolicidal agents can be used during the peroperative period. However, when the cavity is totally explored, this diagnosis can be made after seeing the opening of the biliary duct. For such cases, the risk of sclerosing cholangitis is present. During puncture of the cyst, bile might not be identified as a result of high intracystic pressure; yet after emptying the contents of the cyst there is a decrease in pressure, which results in the drainage of the bile into the cavity. The opening of the biliary duct can also be identified following careful exploration. Owing to this event, some studies have claimed that the utilization of scolicidal agents is not appropriate for hydatid cysts [13,14]. However, scolicidal agents of a volume equal to the amount aspirated, when given into the cavity, is diluted in the cystic fluid; hence it is not exactly known what percentage passes into the biliary system. In our series, none of the 12 patients who received injections of scolicidal agents developed sclerosing cholangitis. During the 10-year follow-up period of these patients, chronic damage of the liver or complications such as biliary cirrhosis were not encountered. In all the patients, if the opening of the biliary duct is found, it should definitely be sutured [2,10,[15][16][17]. It is reported that should the opening of the duct not be sutured the risk of biliary fistula increases [10]. In our series, the opening of the duct was not seen in five of six patients who developed a biliary fistula; in the other patients it was identified and sutured. The biliary fistula incidence in for patients whose ducts were not sutured was 29.4% and it 4.5% in patients whose ducts were sutured; the difference was statistically insignificant (p = 0.06). Therefore, although a direct connection could not be established for the development of biliary fistula and suturing the opening of the biliary duct, it should be sutured if it is identified. In 4 of 16 patients who underwent omentoplasty, the opening of the duct was not identified, yet they did not develop biliary fistulas.

The main point of controversy for conservative methods is the choice of the approach to the cavity [2,16,17]. Partial cystectomy was performed in all cases in our series. With such a technique we speed up the healing process by decreasing the size of the cyst cavity and minimize the risk of secondary infection [3]. Many authors have recommended the use of cavitary drainage in patients with biliary-cystic communication [15,16,18]. Xu Minggian [17] advocated that omentoplasty be performed following sufficient debridement of the cavity and after carefully evaluating such factors as the size of the cavity and the thickness of the cyst wall as well as determining if the cyst is collapsing. Elhamel and Murthy [19] claimed that hydatid cysts that had biliary-cystic communication were not creating any obstacle to performing omentoplasty. For the patients with cavitary drainage, they reported a 52.0% infection rate and a 21.7% biliary fistula rate [19]. They did not encounter any infections or biliary fistulas in patients in whom they had carried out omentoplasty; however, when they combined cavitary drainage with omentoplasty, the incidence of infections and biliary fistulas increased. Kumar and Chattopadhyay [12] stated that after closing the communication with the biliary ducts with a suture, if an omentoplasty was performed the incidence of biliary leakage was as low as 1.5%. In our series, the incidence of biliary fistula was 26% for the patients with cavitary drainage, whereas in those with omentoplasty no biliary fistulas were observed. This difference was not statistically significant. The duration of the hospital stay and complication rates were similar in the two groups. Zaouche et al. [2] stated that when they applied cavitary drainages the results were less satisfactory with regard to specific complications and duration of the hospital stay. We think that this observation is related to resorption-increasing and healing-promoting features of the greater omentum.

For occult intrabiliary ruptures that do not have bile-stained cystic fluid, the use of 20% hypertonic saline or 0.5% cetrimidechlorohexidine is appropriate. Although the opening of the duct is sutured when it is identified, the risk of biliary fistula is not increased in cases whose duct has not been identified. Because the two techniques provide comparable results in the treatment of occult intrabiliary ruptured hydatid cyst of liver, omentoplasty is an alternative for treating such cases [19,20].