Confounding by Indication Is a Major Issue in the Available Evidence on Role of Portal Vein Resection in Patients Undergoing Curative Surgery for Klatskin Tumour.

Abstract

Dear Editor, Visceral Medicine has recently published interesting articles on treatment strategies for improving outcomes in patients with Klatskin tumour [1–4]. We have a particular interest in these articles as we have systematically been reviewing the literature on outcomes of portal vein resection (PVR) in patients with Klatskin tumour undergoing curative surgical resection. Considering that Klatskin tumour has been the focus of recently published articles in Visceral Medicine, we recognized this as a great opportunity to discuss our findings. Klatskin tumour is a rare tumour with an annual incidence of 1 in 100,000 [5]. It accounts for up to 60% of cholangiocarcinomas [6]. Complete surgical resection with achievement of negative resection margins remains the only curative treatment [1]. However, longitudinal intraductal tumour extension and the risk of vascular encasement associated with Klatskin tumour would make achievement of negative resection margins challenging. Consequently, there have been ongoing efforts to identify appropriate surgical strategies targeting achievement of negative resection margins in cases with Klatskin tumour. Considering that the portal vein is involved (microscopically and macroscopically) in a conspicuous proportion of patients with Klatskin tumour [7], routine PVR during surgical resection of Klatskin tumour has been recommended by some authors for achievement of negative resection margins [8–10]. Nevertheless, because PVR is technically challenging and may be associated with significant morbidity and mortality, its routine use has been controversial. Two meta-analyses have previously compared outcomes of PVR and no PVR in patients with Klatskin tumour [11, 12]. However, most of the included studies in previous meta-analyses did not provide data on baseline characteristics of their included population. Knowledge about the baseline characteristics of patients undergoing curative surgery with PVR in comparison with those undergoing curative surgery without PVR is crucial to make meaningful conclusions.