Subsegmental approaches to S7: anatomic laparoscopic transdiaphragmatic and nonanatomic robotic transthoracic.

Background: Minimally invasive liver surgery of postero-superior segments (S4a, S7, S8) remains a challenge. The caudal view, an increased distance between trocars and the operative field, and the liver fulcrum limiting the view, contribute to the difficulty [1, 2]. We and other groups have previously reported the use of intercostal trocars to access subdiaphragmatic tumors (transdiaphragmatic approach) [3-5], only few reports on a laparoscopic total transthoracic approach, none (to our knowledge) dynamic manuscripts of a total transthoracic robotic approach, and none (to our knowledge) that use preoperative port site and anatomic modelling exist. Further, we developed a total transthoracic (thoracoscopic) approach to avoid a hostile abdomen, while bringing viewing axis and instruments close to the target [6-10]. In this context, this report details the advantages of a laparoscopic vs. robotic transthoracic approach. According to institutional protocol, reports of individual cases in print or video format do not require institutional review board approval.

Patient: A 68-year-old male on peritoneal dialysis with left colon adenocarcinoma and a single synchronous liver metastasis in S6-7 close to the root of the right hepatic vein underwent a laparoscopic transdiaphragmatic metastasectomy. Two years later, the patient developed a recurrent 1.5 cm liver metastasis in S7, which lend itself to a robotic transthoracic approach.

Technique: Following 3-D modelling and virtual port placement planning, the first metastasectomy was performed laparoscopically using a transdiaphragmatic approach. The recurrence was managed transthoracically due to more apical, subdiaphragmatic location. For this operation, a robotic approach was optimal as robotic wrist articulation facilitates manipulation via the limited intercostal space. This was particularly helpful during the diaphragmatic reconstruction.

Conclusions: Total transthoracic liver surgery is certainly an advanced procedure requiring superior MIS liver skills. Recommendations for starting with a total transthoracic approach are not unlike from starting a standard, none-transthoracic liver surgery. Early on in the experience we recommend advanced liver MIS skills, and single, small, subdiaphragmatic tumors away from major vessels. Nonetheless, when these recommendations are followed a total transthoracic approach may be safer and result in less access trauma, than traversing a hostile abdomen to reach the posterior-superior liver. Both laparoscopic and robotic transthoracic approaches can facilitate the resection of subdiaphragmatic tumors, especially in patients with hostile abdomens. While the laparoscopic approach has advantages due to a broader spectrum of available surgical tools (flexible tip camera, parenchymal dissection, and energy devices), the robotic wrist articulation facilitates manipulation via the restricted intercostal space.