**2. Challenges, instrumentation, and techniques**

Despite its early use in upper GI surgery, the LESS approach was slow to gain acceptance until recently, possibly due to technical difficulties, the need for specialized instruments, and the lack of clear benefits in comparison with conventional minimally invasive surgery. Close proximity of laparoscopic instruments and camera lens often results in intracorporeal instrument collision or "sword fighting", hindering the surgeon from operating dextrously within the operative field. Visibility of the operative field afforded by the camera assistant is also limited because of the restriction in freedom to manoeuvre the camera lens to minimize instrument clashing. Moreover, intracorporeal dissection and suturing are challenging because of the limited range of movement of the laparoscopic instruments working along the same axis with lack of triangulation [3, 4].

Several techniques and advancements have been introduced to overcome constraints associated with LESS approach. New access devices have been designed and commercialized and are chosen according to the discretion of the surgeons in each institute. The most commonly used are multichannel single-port devices (e.g. Quad Port®, Tri Port®, SILS Port®) or single-channel devices in which multiple trocars can be placed (e.g. GelPOINT® and SSL port®) [5]. There are also devices of art which allow the use of items in the operating room, such as surgical glove with adaptation of trocars in each finger [6].

Another important advance in the development of LESS surgery was the appearance of modified curved instruments, articulated and reusable pre-bent, which provide better force application at instrument tip during dissection and improved intraoperative ergonomics [7]. Needlescopic instruments have been rediscovered, as they can be introduced through a small puncture that requires no formal closure [8, 9]. Low-profile camera systems and laparoscopes with high definition and flexible tip options (e.g. ENDOEYE® and Ideal Eyes®) have also been developed to reduce crowding with other instruments and improve visualization [5]. Additionally, instruments clashing can further be ameliorated by the cross-hand technique, which allows surgeons to manipulate instruments in a more intuitive way [10].

Finally, the need for a retraction mechanism that does not require an additional port led to the development of several techniques and manoeuvres such as patient repositioning and utilization of gravity and insertion of gauze between surgical planes [11, 12]. Other procedure-specific manoeuvres for internal retraction are discussed in the relevant sections.

### **3. Specific LESS applications in upper GI surgery**

The application of LESS approach in upper GI surgery was first described in 1997 by Navarra et al. who reported a series of 30 cases of LESS cholecystectomy performed via a single umbilical incision [13]. Subsequently, many clinical series and randomized controlled trials (RCTs) have been reported, and almost the entire spectrum of surgical procedures for upper GI tract diseases has been described and shown to be feasible.

#### **3.1 LESS gastric surgery**

#### *3.1.1 LESS gastrectomy*

Since the first description by Omori et al. in 2011 [14], only few case series have been published on LESS gastrectomy for gastric tumours, mostly from Korea and Japan [11]. *All these series* have reported techniques and outcomes of LESS distal gastrectomy, while LESS total and proximal gastrectomy and LESS wedge resection have only been reported as individual cases [15–18]. This is because the procedure is complex and technically difficult to perform, and there are concerns regarding oncologic safety. Favourable factors for performing LESS distal gastrectomy include previous experience with conventional multiport laparoscopic gastrectomy and low patient BMI [19].

**57**

*LaparoEndoscopic Single-Site Upper Gastrointestinal Surgery*

In early experiences with the technique, additional needlescopic instruments were required outside of the single incision [14, 20]. For pure LESS distal gastrectomy, the access is transumbilical, and a percutaneous suture is often used for liver retraction. Gastric mobilization, lymph node dissection, and reconstruction are generally performed in the same manner as in conventional laparoscopic distal gastrectomy with few modifications. In performing LESS D2 gastrectomy, the suprapancreatic lymph node dissection, especially station 11p, can be technically challenging because it lies behind the pancreas and is vertical to the direction of instruments, and some authors recommend incomplete safe exploration [21]. Alternatively, mid-pancreas mobilization and traction have been described to achieve complete dissection of station 11p lymph nodes without assistance [22]. Billroth II and extracorporeal or intracorporeal uncut Roux-en Y gastrojejunostomy remain the most commonly used methods for reconstruction in pure LESS distal gastrectomy [21, 23]. Recently, unaided deltashaped (uDelta) gastroduodenostomy has been introduced as a modification of the original advanced assistance-dependent delta-shaped anastomosis, which is considered a safe and more reproducible reconstruction option, with similar

Comparative series between conventional multiport laparoscopy and LESS approach for distal gastrectomy have recently been reported. These studies demonstrated comparable outcomes in terms of operative time, conversion, postoperative mortality, lymph node harvest, R0 resection, and 5-year overall and disease-free survival between the two groups, illustrating the safety and feasibility of LESS distal gastrectomy for both early and advanced gastric cancer [25–28]. Conversely, while no significant differences in the postoperative complications were noted between the two approaches in patients with early gastric cancer [25, 26], the overall complication rate was significantly lower after LESS distal gastrectomy for advanced gastric cancer [28]. Pointing to faster recovery, studies evidenced earlier initiation of oral intake, lower pain scores on postoperative day 0 and 1, less analgesics requirements, and shorter hospital stay for the LESS approach than the conventional laparoscopic counterpart [26–28]. Only one study evaluated the cosmetic outcomes using the numerical rating scale assessment of the scar and reported more

In a separate analysis, when reduced-port laparoscopic and LESS distal gastrectomy for early gastric cancer were compared, no significant differences were observed in the perioperative and oncologic outcomes. However, there were more females and nonobese patients in the LESS group [29]. Recently, Suh et al. reported the results of 16 patients who underwent LESS distal gastrectomy with uDelta gastroduodenostomy or uncut Roux-en Y gastrojejunostomy. There were no significant differences in mean operative time, transfusion rates, hospitalization, anastomosisrelated complications, and 30-day mortality. Interestingly, the reconstruction time

LESS intragastric resection is a novel approach that has mainly been employed in the management of gastric stromal tumours, although its use for gastric bezoar removal has been described [30]. The procedure is particularly useful in cases of

for uDelta was shorter than that for Roux-en Y anastomosis [24].

*DOI: http://dx.doi.org/10.5772/intechopen.82486*

*3.1.1.1 Technical considerations*

anatomical results [24].

satisfaction in the LESS group [26].

*3.1.2 LESS intragastric surgery*

*3.1.1.2 Outcomes*

## *3.1.1.1 Technical considerations*

*Recent Advances in Laparoscopic Surgery*

adaptation of trocars in each finger [6].

more intuitive way [10].

shown to be feasible.

*3.1.1 LESS gastrectomy*

patient BMI [19].

**3.1 LESS gastric surgery**

discussed in the relevant sections.

**3. Specific LESS applications in upper GI surgery**

hindering the surgeon from operating dextrously within the operative field. Visibility of the operative field afforded by the camera assistant is also limited because of the restriction in freedom to manoeuvre the camera lens to minimize instrument clashing. Moreover, intracorporeal dissection and suturing are challenging because of the limited range of movement of the laparoscopic instruments

Several techniques and advancements have been introduced to overcome constraints associated with LESS approach. New access devices have been designed and commercialized and are chosen according to the discretion of the surgeons in each institute. The most commonly used are multichannel single-port devices (e.g. Quad Port®, Tri Port®, SILS Port®) or single-channel devices in which multiple trocars can be placed (e.g. GelPOINT® and SSL port®) [5]. There are also devices of art which allow the use of items in the operating room, such as surgical glove with

Another important advance in the development of LESS surgery was the appearance of modified curved instruments, articulated and reusable pre-bent, which provide better force application at instrument tip during dissection and improved intraoperative ergonomics [7]. Needlescopic instruments have been rediscovered, as they can be introduced through a small puncture that requires no formal closure [8, 9]. Low-profile camera systems and laparoscopes with high definition and flexible tip options (e.g. ENDOEYE® and Ideal Eyes®) have also been developed to reduce crowding with other instruments and improve visualization [5]. Additionally, instruments clashing can further be ameliorated by the cross-hand technique, which allows surgeons to manipulate instruments in a

Finally, the need for a retraction mechanism that does not require an additional port led to the development of several techniques and manoeuvres such as patient repositioning and utilization of gravity and insertion of gauze between surgical planes [11, 12]. Other procedure-specific manoeuvres for internal retraction are

The application of LESS approach in upper GI surgery was first described in 1997 by Navarra et al. who reported a series of 30 cases of LESS cholecystectomy performed via a single umbilical incision [13]. Subsequently, many clinical series and randomized controlled trials (RCTs) have been reported, and almost the entire spectrum of surgical procedures for upper GI tract diseases has been described and

Since the first description by Omori et al. in 2011 [14], only few case series have been published on LESS gastrectomy for gastric tumours, mostly from Korea and Japan [11]. *All these series* have reported techniques and outcomes of LESS distal gastrectomy, while LESS total and proximal gastrectomy and LESS wedge resection have only been reported as individual cases [15–18]. This is because the procedure is complex and technically difficult to perform, and there are concerns regarding oncologic safety. Favourable factors for performing LESS distal gastrectomy include previous experience with conventional multiport laparoscopic gastrectomy and low

working along the same axis with lack of triangulation [3, 4].

**56**

In early experiences with the technique, additional needlescopic instruments were required outside of the single incision [14, 20]. For pure LESS distal gastrectomy, the access is transumbilical, and a percutaneous suture is often used for liver retraction. Gastric mobilization, lymph node dissection, and reconstruction are generally performed in the same manner as in conventional laparoscopic distal gastrectomy with few modifications. In performing LESS D2 gastrectomy, the suprapancreatic lymph node dissection, especially station 11p, can be technically challenging because it lies behind the pancreas and is vertical to the direction of instruments, and some authors recommend incomplete safe exploration [21]. Alternatively, mid-pancreas mobilization and traction have been described to achieve complete dissection of station 11p lymph nodes without assistance [22]. Billroth II and extracorporeal or intracorporeal uncut Roux-en Y gastrojejunostomy remain the most commonly used methods for reconstruction in pure LESS distal gastrectomy [21, 23]. Recently, unaided deltashaped (uDelta) gastroduodenostomy has been introduced as a modification of the original advanced assistance-dependent delta-shaped anastomosis, which is considered a safe and more reproducible reconstruction option, with similar anatomical results [24].

#### *3.1.1.2 Outcomes*

Comparative series between conventional multiport laparoscopy and LESS approach for distal gastrectomy have recently been reported. These studies demonstrated comparable outcomes in terms of operative time, conversion, postoperative mortality, lymph node harvest, R0 resection, and 5-year overall and disease-free survival between the two groups, illustrating the safety and feasibility of LESS distal gastrectomy for both early and advanced gastric cancer [25–28]. Conversely, while no significant differences in the postoperative complications were noted between the two approaches in patients with early gastric cancer [25, 26], the overall complication rate was significantly lower after LESS distal gastrectomy for advanced gastric cancer [28]. Pointing to faster recovery, studies evidenced earlier initiation of oral intake, lower pain scores on postoperative day 0 and 1, less analgesics requirements, and shorter hospital stay for the LESS approach than the conventional laparoscopic counterpart [26–28]. Only one study evaluated the cosmetic outcomes using the numerical rating scale assessment of the scar and reported more satisfaction in the LESS group [26].

In a separate analysis, when reduced-port laparoscopic and LESS distal gastrectomy for early gastric cancer were compared, no significant differences were observed in the perioperative and oncologic outcomes. However, there were more females and nonobese patients in the LESS group [29]. Recently, Suh et al. reported the results of 16 patients who underwent LESS distal gastrectomy with uDelta gastroduodenostomy or uncut Roux-en Y gastrojejunostomy. There were no significant differences in mean operative time, transfusion rates, hospitalization, anastomosisrelated complications, and 30-day mortality. Interestingly, the reconstruction time for uDelta was shorter than that for Roux-en Y anastomosis [24].

#### *3.1.2 LESS intragastric surgery*

LESS intragastric resection is a novel approach that has mainly been employed in the management of gastric stromal tumours, although its use for gastric bezoar removal has been described [30]. The procedure is particularly useful in cases of

endophytic tumours <5 cm, with unfavourable locations, such as the fundus, high lying in the posterior wall of the stomach, or close to the gastroesophageal junction or the pyloric ring [31–33]. Several advantages are offered by the LESS intragastric approach including direct visualization of tumours during resection, minimal dissemination of the tumour into the peritoneal cavity, easy delivery of the specimen through the single-site incision, and extracorporeal repair of the gastrotomy site [31]. In addition, it obviates the need for multiple incisions, thus resulting in better cosmesis, and reduces the possibility of deformity by significantly preserving the normal gastric tissue with more precise resection compared with conventional laparoscopic wedge resection [33].
