**2. Techniques for esophagogastric anastomosis**

#### **2.1 General principles**

Esophageal anastomosis healing follows the main phases of tissue healing: inflammation (day 0 to day 4), proliferation (day 5 to day 10), and remodeling (after day 10) phase, with the maximum strength being achieved between day 10 and 14 [15]. A series of technical general principles must be followed during esophagogastric anastomosis creation. First of all, appropriate apposition of esophageal submucosa with the gastric wall is necessary, since submucosa collagen mainly contributes to the integrity and the mechanical strength of the anastomosis [10].

The esophagogastric anastomosis can be hand-sewn, completely stapled, using either a circular or linear stapler, or semi-mechanical, where a linear stapler is preferred for posterior wall reconstruction, while the anterior wall of the anastomosis is performed in a hand-sewn fashion [14]. Based on the anatomic relationship of the esophageal stump and the gastric conduit after the anastomosis, end-to-end, end-toside, and side-to-side anastomoses are described.

The first step during the thoracoscopic phase of Ivor-Lewis esophagectomy is the division of the esophagus, which should be done at the level of the arch of the azygos vein. In addition, it is proposed to create an esophagotomy at the anterior wall rather than transect the esophagus, to achieve better traction for anvil insertion, when the OrVil technique is not selected [16]. The absence of tension or torsion on the anastomosis, as well as gentle tissue manipulations, are necessary to maintain adequate perfusion [16].

#### **2.2 Handsewn anastomosis techniques**

The decision to perform an intrathoracic esophagogastric anastomosis via a thoracoscopic hand-sewn technique demands advanced technical skills and is associated with prolonged operative time [10]. An end-to-end or end-to-side anastomosis is performed between the distal esophagus and the greater curvature of the gastric conduit. Absorbable or nonabsorbable sutures can be selected and the anastomosis may be performed in a continuous or interrupted fashion, in a single or double-layer technique. Single-layer anastomosis is conducted with absorbable or nonabsorbable sutures occupying all wall layers, while the double layer-technique uses an outer row of sutures on the seromuscular layer, followed by an additional inner absorbable suture layer for mucosa inversion after gastrostomy on the great curvature has been performed. It is advisable to place Connell sutures at both ends of the posterior wall to ensure mucosal apposition before proceeding to the anterior wall. After nasogastric tube placement, anterior wall reconstruction is performed [17].

Limited literature exists on hand-sewn esophagogastric anastomosis in the era of minimally invasive esophagectomy [18]. Charalabopoulos et al. published a large cohort study of laparoscopic two-stage esophagectomy with a completely hand-sewn intrathoracic anastomosis, with promising results. The surgical procedure involved the creation of a two-layer end-to-side esophagogastric anastomosis. Outcomes were promising, reporting an anastomotic leak incidence of 2.5 (2 out of 80 patients) and 90-day mortality of 5%. Finally, 10 out of 80 patients presented anastomotic strictures and were treated with endoscopic balloon dilatations. The authors conclude that intrathoracic manual anastomosis is a safe and easily reproducible technique during minimally invasive Ivor-Lewis, with satisfactory oncological short and long-term outcomes when performed in specialized esophageal cancer centers [18]. Carr et al. report reduced incidence of anastomotic leak and postoperative stricture by performing double-layer anastomosis, although they are associated with longer operative time and higher costs [10].

In their prospective cohort study, Ramirez et al. presented the outcomes of intracorporeal hand-sewn anastomosis in 27 patients who underwent laparoscopic Ivor-Lewis esophagectomy. The anastomosis technique included two PDS running suture layers in the posterior wall and one PDS running layer in the anterior wall, followed by omentoplasty. An articulated needle holder (FlexDex) for better surgical ergonomics was also used. The mean operative time needed for anastomosis creation was 60 minutes. The authors report an anastomotic rate of 14.8%, while in 7.4% of participants, reoperation was performed [19].

Intracorporeal hand-sewn esophagogastric anastomosis carries the burden of a steep learning curve, since manual anastomosis demands a higher level of technical skills, experience, and background compared to mechanical staplers [19].

In addition, the literature contains reports of hand-sewn esophagogastric anastomosis during robot-assisted Ivor-Lewis esophagectomy with excellent outcomes regarding anastomotic leak rate [20]. Notably, the advent of robotic esophagectomy has triggered the interest back in hand-sewn anastomosis due to increased degrees of freedom offered compared to conventional thoracoscopy [16, 21].

In conclusion, thoracoscopic hand-sewn anastomosis, although challenging, is a feasible and safe technique, presenting relatively low rates of anastomotic leak and stricture rate, even during the learning curve period. The emersion of flexible ergonomically advantageous tools may facilitate manual anastomosis creation (**Figure 1**).

#### **2.3 Stapled anastomosis techniques**

The advent of mechanical stapled anastomotic devices in 1977 offered the advantage of reduced operative time and technical feasibility independently of the surgeon's *Prevention of Anastomotic Leak in Minimally Invasive Esophagectomy: The Role of Anastomotic… DOI: http://dx.doi.org/10.5772/intechopen.106041*

#### **Figure 1.**

*Final result of a hand-sewn end-to-side esophagogastric anastomosis during laparoscopic Ivor-Lewis esophagectomy.*

experience and skills [22]. Mechanical esophagogastric anastomosis is mainly performed with the use of a circular end-to-end anastomosis stapler (EEA stapler) or a linear cutting gastrointestinal stapler (GIA stapler) [10]. In esophageal surgery, the use of circular staple anastomosis has been adopted since the 1990s, while linear stapled anastomosis was introduced in 1998 [23].

#### *2.3.1 Linear side-to-side stapled anastomosis*

To create an intrathoracic side-to-side functional anastomosis, usually a 30- or 45-mm gastrointestinal anastomosis (GIA) stapler is selected, securing the anastomotic site with a triple row of titanium staples [10]. After gastric conduit mobilization and alignment of the esophageal posterior wall and gastric anterior wall, the large jaw of an Endo GIA stapler is placed into the gastrostomy and the thin jaw is inserted into the esophagotomy [10]. After stapler firing, the posterior wall of the anastomosis has been created and nasogastric tube has been inserted and the anterior wall can be reconstructed with another staple firing [10]. Alternatively, after stapling of the opposing walls and creation of a V-shaped anastomosis, anterior walls are sutured in a single-layer running fashion [23]. The side-to-side linear anastomosis technique presents numerous advantages, since the linear stapler is easily inserted and used into the thoracic cage, creating a wide anastomosis with a low stricture creation rate [10]. Furthermore, it is an easily standardized technique with a low rate of technical errors [24]. However, sufficient esophageal stump length is needed and the retention of a gastric conduit stump leads to a higher rate of ischemic anastomotic fistula formation [25]. In addition, special technical skill is required for closing sites of initial gastrostomy and esophagotomy discourages surgeons from choosing it during minimally invasive intrathoracic anastomosis formation [25].

#### *2.3.1.1 Linear vs. circular anastomosis*

A meta-analysis by Zhou et al. was the first to compare linear with circular-stapled esophagogastric anastomosis during open Ivor-Lewis esophagectomy. Outcomes favored linear anastomosis regarding postoperative anastomotic stricture, while no statistically significant difference was proved regarding anastomotic leakage rate and 3-month mortality [23].

#### *2.3.1.2 Linear vs. handsewn anastomosis*

According to a meta-analysis by Deng and colleagues, esophagogastric anastomosis created in a linear fashion presents a lower incidence of anastomotic leak compared to the handsewn anastomosis. Possible mechanisms for this outcome include the less traumatic character of mechanical staplers to tissues, the reduced tension on the anastomosis due to lateral stay sutures, and, finally, the three layers of titanium staplers, which contribute to the mechanical strength of the anastomosis. At the same time, the linear-stapled technique is superior to hand-sewn anastomosis regarding anastomotic stricture rate [24].

The literature contains insufficient data regarding the clinical outcomes of linearstapled esophagogastric anastomosis after minimally invasive esophagectomy for esophageal cancer. Gao et al. studied the short-term outcomes of 34 consecutive patients, in whom the creation of a mechanical side-to-side linear stapled anastomosis was decided for minimally invasive Ivor-Lewis. The results were promising, with no mortalities or serious postoperative complications noted. Anastomotic leakage presented in only one patient (2.9%) and was treated without intervention, while no conversion to an open approach was needed. In conclusion, the authors suggest that linear-stapled esophagogastric anastomosis is a safe and feasible option regarding short-term outcomes, although associated with a steep learning curve [25].

#### *2.3.2 Circular stapled anastomosis*

Mechanical circular stapled anastomosis technique is the most frequently used method for intrathoracic esophagogastric anastomosis in the era of minimally invasive Ivor-Lewis. The surgical procedure includes the insertion of an anvil into the esophageal stump, followed by apposition and application of the anvil rod with the stapler shaft of an intraluminal EEA placed into the gastric conduit. Based on the method of anvil introduction, circular stapled intrathoracic anastomoses are performed with the transorally inserted anvil technique, using the Orvil™ device, or with the hand-sewn purse-string stapled anastomosis technique [26]. With the aforementioned procedure, an end-to-end esophagogastrostomy is performed, enhanced by a double row of staplers in a circular fashion. Anvil size is selected based on esophagus diameter and literature reports no relationship between anvil size and risk for anastomotic leak [10].

### *2.3.3 Circular-stapled anastomosis using a transorally inserted anvil (Orvil™)*

The first use of Orvil EEA for the creation of end-to-side esophagogastric anastomosis for Ivor-Lewis MIE is reported by Nguyen et al. in 2008 [27]. The transoral OrVil circular-stapled technique presents a safe, time-efficient, and reproducible method for esophagogastric anastomosis. However, the cost associated with OrVil

*Prevention of Anastomotic Leak in Minimally Invasive Esophagectomy: The Role of Anastomotic… DOI: http://dx.doi.org/10.5772/intechopen.106041*

renders this technique too expensive, while transoral insertion of the anvil may cause thoracic infection and throat injury [28]. In addition, the OrVil anvil comes only in the size of 25 mm.

OrVilTM is preconnected to a long PVC nasogastric-like tube with anchoring sutures [10]. After esophageal resection using a linear stapler and advancement of the OrVil up to the end of the esophageal stump, an incision is made at the esophageal staple line and the blue sutures are transected. The anvil is separated from the orogastric tube, is orientated appropriately and anastomosis is performed, by docking the anvil to the EEA spike and firing the stapler.

According to a retrospective observational study by Zhang et al., which included patients undergoing Ivor-Lewis minimally invasive esophagectomy, no statistically significant difference was noticed regarding minor and major leakage rates, as well as anastomotic stricture rates when the transoral Orvil technique group was compared to purse-string technique group.

Due to its mechanical similarity with a nasogastric tube, misplacement of the OrVil through the patient's nostril may be done in case of sparse education and communication with the person assisting. In addition, several maneuvers are necessary to avoid obstacles during the advancement of the anvil portion up to the esophageal stump. There are specific maneuvers to prevent and resolve these occurrences. First of all, the smooth portion of the disk should face the patient's hard palate. Secondly, lifting and shaking the patient's jaw can help advance the anvil at the point of the piriform sinus, Furthermore, an obstacle at the level of the aortic arch can be overcome by a tugging back and forth between the surgeon at the chest and the assistant at the head of the patient. Last but not least, the cuff of the endotracheal balloon can be transiently deflated during anvil advancement [17]. In addition, one should be careful during the insertion of the stapler through the trocar, since a position perpendicular to the vertebral plane is necessary [16]. What is more, a 10 mm laparoscopic fan retractor for lung parenchyma may be useful to achieve better exposure to upper mediastinum and facilitate anvil and stapler engagement. Control of the anvil by holding it in its proximal part can also be achieved using a laparoscopic grasper, to avoid any damage to flanges. During engagement, attention should be paid to avoid incorporating any adjacent tissues, as well as to hold in the engagement place for 30 seconds before firing, to achieve complete tissue compression. Finally, in cases of very proximal tumors and insufficient length of gastric conduit, Grubic et al. propose complete gastric mobilization including the duodenal Kocher maneuver, to achieve a tension-free anastomosis [29]. Gentle manipulations are required, to avoid dissociation of the anvil from the tube. In case of dissociation, the anvil can be retrieved using the blue retrieval suture [17].

#### *2.3.4 Hand-sewn purse-string stapled anastomosis*

The circular stapled end-to-end intrathoracic anastomosis (EEA) is less time consuming than the hand-sewn technique and is feasible even with a shorter length of gastric conduit available compared to the linear-stapled technique. While hand-sewn purse-string stapled anastomosis is a popular technique in open esophagectomy, it is technically challenging under thoracoscopy [28].

After sharp dissection of the esophagus, the anvil of an EEA is inserted into the esophageal stump under proper pressure. Attention should be made to use the largest anvil size the esophageal stump can accommodate, to avoid postoperative anastomotic strictures. Usually, a 25 mm anvil is used. Esophageal intraoperative dilation may be

beneficial in cases of difficulty while inserting the anvil. After anvil placement, a baseball stitch fashion suture is placed to secure the anvil position, including esophageal mucosa. A second purse-string suture is placed outside the previous suture. After insertion of the EEA handle through a 2–2.5 cm gastrostomy, the spike of the EEA is advanced through the gastric wall and is engaged with the anvil and the handle is fired [17]. Resection of the open end of the gastric conduit is performed after anastomosis inspection. After anastomosis creation, a nasogastric tube is advanced to the gastric conduit under manual guidance [10].

The most difficult step during thoracoscopic hand-sewn purse-string stapled anastomosis is to deliver successfully the anvil into the esophageal stump. Various techniques have been proposed. A special purse-string clamp device was used by Xie et al. to insert a purse-string suture over the esophageal stump. This method is challenging technically at the high level of the thorax and also requires special equipment [30]. Zhan et al. proposed a modification of hand-sewn circular stapled anastomosis, using a zero-silk suture at 5 cm proximal to the tumor, and placing the first stitch at the 3 o'clock position of the esophageal wall, the second at the 12 o'clock position, and the third at the 9 o'clock position, and finally, the fourth stitch at the 3 o'clock position, after esophagus rotation. After securing the suture with two knots, the anterior esophageal wall is resected and the anvil is inserted. Mean anvil fixation time was 7.1 minutes, compared to the range of 10–18 reported in the literature [28].

It is important to line up the staple line with the body of the gastric conduit and to leave at least a centimeter free between the anastomosis site and the end of the linear staple line [17].
