ORIGINAL ARTICLE – HEPATOBILIARY TUMORS Theory of Relativity for Posterosuperior Segments of the Liver G. Fiorentini, MD, F. Ratti, MD, F. Cipriani, MD, L. Cinelli, MD, M. Catena, MD, PhD, M. Paganelli, MD, and L. Aldrighetti, MD, PhD Hepatobiliary Surgery Division, IRCCS San Raffaele Hospital, Milan, Italy ABSTRACT Background. The accessibility to posterosuperior seg- ments of the liver has traditionally constituted a restrain to adopt the laparoscopic approach in this setting. To over- come this challenge, multiple approaches have been reported in literature. Total transabdominal approach has been previously described for this purpose, even though the rationale to standardly adopt it and a technical depiction of how to achieve an optimal mobilization has never been specifically addressed. Methods. Total transabdominal purely laparoscopic approach to posterosuperior segments of the liver is pre- sented, with detailed emphasis to the rotational motions targeted in laparoscopy. A literature review is presented to summarize all other possible accesses to posterosuperior area of the liver. The institutional series for the laparo- scopic approach to Sg 7, Sg 6?7, and Sg8 is retrospectively described. Results. Three rotational motions of the liver are specifi- cally addressed in a video presentation and described for the laparoscopic total-transabdominal approach; the local institutional series using this approach is presented. Other miscellaneous approaches identified from literature encompassing variations in operative position, transab- dominal, transthoracic, and combined approaches are described. Conclusions. Complete mobilization of the ligaments of the liver leads to a rotation of the transection line in front of the operator’s view, allowing to achieve a safe total trans- abdominal laparoscopic approach to the posterosuperior ligaments of the liver, without compromising the vascular inflow control, the possibility to convert to open approach, nor requiring potentially harmful decubitus. Technical feasibility, clinical benefits, and oncological adequacy of laparoscopic liver resection have been docu- mented with high level of evidence in recent years. Initially developing the approach to the ‘‘laparoscopic’’ segments (2, 3, 4b, 5), the wide-spreading to ‘‘nonlaparoscopic’’ segments (4a, 7, 8) has been quick. The approaches to posterosuperior (Segment 7) and superior segments (4a and 8) have been multiple and var- iegates, seeing different patient positioning and operative set-up, increasing potentially unfavourable variables rela- ted to lack of standardization. 1–23 Potentially, surgeons dealing with posterosuperior segments find themselves having to operate in uncomfortable or unusual settings, such as lateral or semiprone decubitus, with lack of an easy inflow control and an incomplete domain of all the sectors of the liver. Furthermore, the use of intercostal ports might be harbinger of increased morbidity. Throughout the development and improvements of technique and technology, 24 total transabdominal approa- ches have been proposed, without sacrificing the supine position, therefore, maintaining access to the hepatic pedicle and avoiding the use of transthoracic ports. For this purpose, it is necessary to perform a complete rotation of the liver in laparoscopy to move the target area to a favorable anterior position, more suitable for resection. The present work has been conceived with the goal of showing in an analytic, step-by-step fashion the rotational motions of the liver in laparoscopy, a topic still poorly tackled in literature, for a total transabdominal approach without any intercostal ports. An educational video is presented with this purpose, and a review of the recent literature has been conducted. Electronic supplementary material The online version of this article (https://doi.org/10.1245/s10434-019-07165-6) contains supplementary material, which is available to authorized users. Ó Society of Surgical Oncology 2019 First Received: 6 November 2018 G. Fiorentini, MD e-mail: fiorentini.guido@hsr.it Ann Surg Oncol https://doi.org/10.1245/s10434-019-07165-6