Preoperative Evaluation and Assessment of Resectability

Evaluation of patients with hilar cholangiocarcinoma is principally an assessment of resecta-bility, since resection is the only effective therapy. First and foremost, the surgeon must assess the patient's general condition and fitness for operation, which usually includes partial hepatectomy. The presence of significant comorbid conditions, chronic liver disease, and/or portal hypertension generally precludes resection. In these patients, biliary drainage is the most appropriate intervention, and the diagnosis should be confirmed histologically if chemotherapy or radiation therapy is anticipated. Patients with potentially resectable tumors occasionally present with biliary tract sepsis, frequently after intubation of the biliary tree. These patients require resuscitation and treatment of the infection before surgery can be considered.

FIGURE 3 Axial MRCP view of a hilar cholangiocarcinoma. An irregular-appearing mass lesion is seen at the confluence of the proximal bile ducts, which appear white in this image. There is dilatation of the intrahepatic biliary radicles. Note the atrophy of the left liver, with dilated and crowded ducts. Abbreviation: MRCP, magnetic resonance cholangiopancreatography. Source: From Jarnagin WR et al., Seminars in Liver Disease 2004; 24: 189-199.

Cholangiocarcinoma And Surgery

FIGURE 3 Axial MRCP view of a hilar cholangiocarcinoma. An irregular-appearing mass lesion is seen at the confluence of the proximal bile ducts, which appear white in this image. There is dilatation of the intrahepatic biliary radicles. Note the atrophy of the left liver, with dilated and crowded ducts. Abbreviation: MRCP, magnetic resonance cholangiopancreatography. Source: From Jarnagin WR et al., Seminars in Liver Disease 2004; 24: 189-199.

Mirizzi Syndrome Ercp

FIGURE 4 Mirizzi syndrome. ERCP view of a biliary stricture caused by a large stone impacted at the neck of the gallbladder. Abbreviation: ERCP, endoscopic retrograde cholangiopancreatography. Source: From Ref. 76.

The preoperative evaluation must address four critical determinants of resectability: extent of tumor within the biliary tree, vascular invasion, hepatic lobar atrophy, and the presence metastatic disease (4). Lobar atrophy is an often-overlooked finding in patients with hilar chol-angiocarcinoma. However, its importance in determining resectability cannot be overemphasized, since it implies portal venous involvement and compels the surgeon to perform a partial hepatectomy, if the tumor is resectable (40). While longstanding biliary obstruction may cause moderate atrophy, concomitant portal venous compromise results in rapid and severe atrophy of the involved segments. Appreciation of gross atrophy on preoperative imaging is important, since it often influences both operative and nonoperative therapy (40). The resectional approach in such cases demands a concomitant partial hepatectomy. On the other hand, if resection is not an option, percutaneous biliary drainage through an atrophic lobe, unless necessary to control sepsis, should be avoided since it will not effect a reduction in bilirubin level. Atrophy is considered to be present if cross-sectional imaging demonstrates a small, often hypoperfused lobe with crowding of the dilated intrahepatic ducts (Fig. 3). Tumor involvement of the portal vein is usually present if there is compression/narrowing, encasement or occlusion seen on imaging studies. Portal vein involvement and/or lobar atrophy are common findings (4,57).

Until recently, there has been no clinical staging system that accounts fully for all of the tumor-related variables that influence resectability, namely biliary tumor extent, lobar atrophy, and vascular involvement. The modified Bismuth-Corlette classification stratifies patients based on the extent of biliary duct involvement by tumor (58). Although useful to some extent, it is not indicative of resectability or survival. The current American Joint Committee on Cancer (AJCC) T stage system is based largely on pathological criteria and has little applicability for preoperative staging. The ideal staging system should accurately predict resectability, the need for hepatic resection and correlate with survival. Such a system would assist the surgeon in formulating a treatment plan and help the patient understand the treatment options and outcome. The authors have proposed a preoperative staging system, using preoperative imaging studies, taking into account the extent of local tumor involvement (4,57). This staging system puts the finding of portal venous involvement and lobar atrophy into the proper context for determining resectability, especially when partial hepatectomy is viewed as an important component of the operative approach (Table 1). For example, a tumor with unilateral extension

TABLE 1 Proposed T Stage Criteria for Hilar Cholangiocarcinoma

Stage

Criteria

T1 Tumor involving biliary confluence +/- unilateral extension to second-order biliary radicles

T2 Tumor involving biliary confluence +/- unilateral extension to second-order biliary radicles

AND ipsilateral portal vein involvement +/- ipsilateral hepatic lobar atrophy T3 Tumor involving biliary confluence + bilateral extension to second-order biliary radicles OR

unilateral extension to second-order biliary radicles with contralateral portal vein involvement OR unilateral extension to second-order biliary radicles with contralateral hepatic lobar atrophy OR main or bilateral portal venous involvement

Source: From Ref. 57.

into second-order bile ducts and associated with ipsilateral portal vein involvement and/or lobar atrophy would still be considered potentially resectable, while such involvement on the contralateral side would preclude a resection. The authors have found that this staging system correlated well with resectability and the likelihood of associated distant metastatic disease (57). The authors' criteria of unresectability are detailed in Table 2.

In many centers, primarily in Japan, a very detailed approach to definition of resectability is often used and is based on direct cholangiography of segmental ducts and cholangioscopy (59,60). This approach generally involves placement of multiple percutaneous biliary drainage catheters in order to allow complete access to the biliary tree. This approach to preoperative biliary drainage and cholangioscopy is often combined with preoperative portal vein emboliza-tion in an effort to lower the risk of postoperative hepatic failure (see below). Such an aggressive diagnostic evaluation appears to increase the resectability but requires a prolonged hospital stay and its true value is unclear (60,61).

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