Minimally invasive esophagectomy

As noted above, Cushiery already reported on five cases of endoscopic esophagectomy through a right thoracoscopic approach, followed by a paper on 26 procedures in 1994 [1, 2]. Consequently, surgeons all over the world worked with empathy and dedication to develop minimally invasive techniques of the existing different variations of esophageal resections [3‐11]. Namely transhiatal, transthoracic and three-field (abdominal–thoracic-–cervical) approaches found their position and therefore a more common use for a minimally invasive approach [10, 12‐19]. In Austria, some specialized departments used their highly developed minimally invasive skills to perform minimally invasive esophageal resections with good outcomes even without publishing their experiences, e. g., Schmid T, Innsbruck and Szinicz G., Bregenz, Austria (personal communication). Others reported on small series more focused on feasibility [20‐25], operative technique [26‐28] and perioperative outcome [11, 29] than on oncological long-term data, quality of life or even cost analysis.

Thereafter in the 1990s and early 2000s, high-volume expert centers formed and as soon as the first large series were published [3], others felt justified to “try this at home”. Nowadays, there are several well-known expert centers on minimally invasive esophagectomy (MIE) all over the world, developing better evidence on the various applied techniques, indications and outcomes. However, only 15% of esophagectomies worldwide are performed by using the conventional laparoscopic-thoracoscopic or robotic approach [30], although better global quality of life, physical function, fatigue, and pain 3 months after surgery have been demonstrated [31].

The newest kids on the block were implementation of telemanipulators called “operation robots” and the integration of enhanced vision such as HD-cameras and 3D imaging [32]. ICG-visualization of organ perfusion and the application of electric nerve stimulation, both with the aim to improve the patients’ outcome, are also on their way to find their place in daily routine. All of them will be discussed below.

Presently there is no gold standard technique for esophagectomy. The choice of the technique strongly depends on tumor location and surgeons’ preference and experience with one or the other technique. The most commonly applied minimally invasive approaches are combined abdominal and transthoracic approaches using the tube-shaped stomach pull-up as a substitute for the resected esophagus (Fig. 1). Two techniques, with the anastomosis intrathoracically (Ivor-Lewis) (Fig. 2 and 3) or in the left neck (McKeown) are the most used [33, 34]. Both of them provide an en bloc resection of the esophagus together with radical mediastinal lymph node dissection under direct visualization [35]. However, open transhiatal esophagectomy (THE; i. e. abdominal approach to the mediastinum, through the diaphragm) is still under debate as an alternative with lower morbidity in some, but not in all studies [36‐38]. With avoiding single lung ventilation, it was considered a technique for rather unfit patients. Nevertheless, the extent of lymph node dissection in the upper mediastinum is very limited from the abdomen keeping in mind that even in adenocarcinoma of the distal esophagus, the rate of positive lymph nodes in the upper mediastinum was as high as 10% in some studies! Therefore, transhiatal resections might show worse oncologic outcomes. However, laparoscopic or robotic assisted transhiatal esophagectomy has been shown to be an even lesser invasive alternative. Laparoscopic THE was demonstrated to be safe and feasible with evidence of reduced blood loss and shorter hospital stay. However, level 1 evidence is lacking and also evaluation of long-term oncologic outcomes is warranted [39, 40].

Since minimally invasive techniques of esophagectomy are demanding, the implementation of such a program strictly depends on the previous experience of the team in high-end laparoscopic surgery as well as in minimally invasive thoracic surgery. The latter has found its way into daily routine relatively later than laparoscopy and the number of experts available to apply new techniques is scarce. Therefore, many teams around the world have adopted a so-called hybrid approach, using minimally invasive surgery in the field of their better expertise and combining it with a conventional access in the other compartment [41]. Some combine laparoscopy with thoracotomy while others prefer the thoracoscopic approach and perform the abdominal part of the operation by conventional midline laparotomy. Those preferring laparotomy argue that the mobilization of the gastric tube including a “Kocher’s maneuver” can be done more easily in an open way and that the main advantage of MIE lies in a less invasive thoracic part. On the other hand, those performing laparoscopy and thoracotomy rely on a “safer” performance of the intrathoracic anastomosis e. g. with oversewing the circular stapled anastomosis in order to avoid leaks. In the MIRO trial [42, 43], 200 patients were randomized to either HMIE (hybrid minimally invasive esophagectomy, with thoracotomy) or open Ivor-Lewis esophagectomy. As a result, HMIE demonstrated to have less postoperative major morbidity, specifically significantly less pulmonary complications. Moreover, in a recent 3‑year follow-up an overall survival of 67% (95% confidence interval [CI] 57–75) in the HMIE group versus 55% (95% CI 45–64) in the open-procedure group was demonstrated [44]. In the MIOMIE trial, an Austrian group compared open esophagectomy versus HMIE (with thoracotomy) as well. They could show that morbidity, mortality, and oncological long-term outcome were equal to the classical open Ivor Lewis approach [45, 46].

However, with enough expertise, both parts can be accomplished minimally invasively when a stepwise approach with proctoring from a high-volume reference center is available in order to steepen the learning curve. Complete MIE has shown to be better than HMIE in terms of postoperative pain and pulmonary complications [47].

Fellowships at high-volume centers, proctoring by experts and credentialing seems reasonable [48].

Like in other highly demanding surgeries like pancreatic resections, the technical term “learning curve” means morbidity, mortality, pain, fear and even high financial burden in daily practice. Osugy et al. have defined the number of 17 MIEs to establish basic skills and a number of 34 cases to attain a similar or better outcome than by conventional (open) approach [49]. In a consensus paper Visser et al. has determined consensus among European MIE experts and identified fundamental items required for training MIE [50].

In the early 2000s, the three-arm Da Vinci (Intuitive, Inc. Intl.) telemanipulator (so-called “operation robot”) attracted the surgeons’ interest and gained worldwide use [64]. In the Medical University Innsbruck, we performed all types of laparoscopic and thoracoscopic standard operations of that time by using it ([65‐74]; Figs. 4, 5, 6 and 7). To sum up, so-called “standard” laparoscopic operations can easily be performed faster and cheaper with conventional laparoscopic technique by trained surgeons. The newer four-arm model of the DaVinci operation robot has several improvements with the potential of a better versatility and therefore lessens the degree to that an on-table assistant has to contribute to the operation in between the former large moving robot arms.

When it comes to esophageal resections, surgeons hope to overcome the shortcomings of conventional thoracoscopy with non-articulated instruments due to the fulcrum effect of the thoracic wall, the remote position of the diaphragmatic hiatus and the meticulous lymph-node dissection in the upper mediastinum, sparing the recurrent laryngeal nerve and the vagus nerve. Better maneuverability, motion scaling, tremor filter and particularly a much more comfortable working position for the surgeon promise a smoother workflow with hopefully better outcomes (Fig. 8). However, it will be difficult to prove a better clinical outcome for the patient compared to conventional MIE [75].

Patient positioning for MIE or RAMIE is also under debate: lateral decubitus versus prone position is debated against each other [99, 100]. Prone position of the patient allows for easier dissection of the esophagus since gravity keeps lung and blood down, thereby enlarging the operative field. Therefore, single lung ventilation is not necessary, thus reducing venous shunting. Moreover, it is more ergonomic for the surgeon. On the other hand, lateral decubitus positioning of the patient makes it easier to reach the upper mediastinum in order to perform lymphadenectomy along the vagus nerve. For those coming from open surgery, it offers a similar anatomic aspect and is also better suitable for emergency conversion to open surgery. To overcome the shortcomings of both methods, a semi-prone positioning with turning the table to the surgeon’s needs seems to be a well-accepted compromise.

For better visual depth perception, three-dimensional (3D) cameras seem promising and might even be a more viable technique over two-dimensions (2D) in terms of short-term outcomes for patients with esophageal cancer [32, 101, 102]. In the current operation robots, they are standard anyway.

Healing of the anastomosis depends mainly on perfusion of the gastric tube. Therefore, identification of a well-perfused part of the stomach for positioning the anastomosis is desirable. Imaging of the tube’s perfusion with indocyanine fluorescein angiography seems promising and might lower the rate of anastomotic insufficiencies. Additional technologies like image flattening, color segmented fluorescence, overlay mode and spy mode might help to standardize imaging of perfusion and even allow for working under fluorescence imaging. However, absolute quantification of blood flow is not possible and preliminary data are controversial (Fig. 9; [103‐110]).

Recurrent laryngeal nerve monitoring (RNM) in esophagectomy was performed for the first time in 2001 by Hemmerling et al. [111]. It took several years until its clinical usefulness had been proven either in the mediastinum or in the neck. It has no impact in operative time, but significantly reduces postoperative vocal cord palsy and consequently pulmonary complications [112‐120].

Enhanced recovery after surgery (ERAS) protocols aim to preserve physiologic functions after surgery. Bed rest, opioids, long fasting, excessive intravenous fluid intake, tubes and drains etc. have been proven to be more harmful than beneficial in the majority of cases despite this was part of “surgical culture” since the ancient times of surgery. ERAS protocols have proven their value in almost all surgical subspecialties. Particularly patients after major surgeries including esophagectomy should profit from this newer fast-track philosophy. In the recent years, ERAS protocols also found their way into clinical practice enabling an improvement of the results and even lowering overall-costs for esophagectomy [121‐135].