Three-Step Hand-Assisted Laparoscopic D2 Radical Gastrectomy for Chinese Obese Patients: A Highly Ef

Three-Step Hand-Assisted Laparoscopic D2 Radical  Gastrectomy for Chinese Obese Patients: A Highly  Efficient and Feasible Surgical Approach

JiaQing Gong*, YongKuan Cao*, YongHua Wang, GuoHu Zhang, PeiHong Wang, GuoDe Luo

Abstract

Three-step hand-assisted laparoscopic D2 radical gastrectomy (HALG) is a modified surgical  procedure that has achieved satisfactory results for obese patients in our surgical center. To fully  elucidate the advantages of this procedure, in this study, comprehensive and in-depth comparative  analyses were performed to assess clinical data from obese gastric cancer patients who underwent HALG, laparoscopic-assisted D2 radical gastrectomy (LAG), and open D2 radical gastrectomy  (OG) in our surgical center during a specific time period. For the 3 groups, incision length was 1.25  cm longer for the HALG group than for the LAG group but was significantly shorter for the HALG  group than for the OG group (P =0.00). The rate of conversion to laparotomy , the pneumoperitoneum time and the number of recovered lymph nodes were significantly better for the  HALG group than for the LAG group (P <0.05). The pain score at day 2 after surgery, intestinal  function recovery time, and duration of postoperative hospital stay were not significantly different  for the HALG and LAG groups ( P >0.05) but were significantly better for the HALG group than for the OG group (P <0.05). There were significantly fewer postoperative complications for the  HALG group than for the LAG and OG groups (P =0.049). According to the results, the  “three-step HALG method” incorporates both the thoroughness of the radical OG approach and  the minimal invasiveness of the LAG approach for obese patients. Thus, the HALG approach is a  relatively safe and extremely feasible surgical procedure for the treatment of these patients.

Key words: hand-assisted laparoscopic D2 radical gastrectomy, laparoscopy-assisted D2 radical  gastrectomy, open D2 radical gastrectomy, obese patients.

Introduction

Obese gastric cancer patients exhibit the large  accumulation and abnormal distribution of abdominal fat; these characteristics seriously affect the  exposure of the operative field. In addition, perivascular fat parcels and lipid deposition on vascular  walls lead to increased vascular fragility; as a result,  slight stretching of blood vessels can easily lead to  vascular rupture and bleeding, which severely affect  the surgical process and increase surgical difficulty  and risk. Furthermore, obesity is frequently associated  with many cardiopulmonary and other chronic diseases that decrease operational tolerance [1]. Therefore, many scholars believe that caution is required  with respect to the use of laparoscopic surgery for obese patients [2, 3]. However, laparoscopic-assisted  D2 radical gastrectomy (LAG) has become a standard  procedure for the radical treatment of advanced gastric cancer because of its unmatched advantages [4, 5]. In recent years, many scholars have continued to investigate the use of LAG for obese gastric cancer patients and have obtained preliminary results [6, 7]. However, the application of laparoscopic techniques  among obese gastric cancer patients still faces the  following bottlenecks. (1) It is difficult to expose the  operative field, the control of bleeding is challenging,  and operation times are lengthy [8]. (2) Laparoscopic  surgeries are extremely difficult and risky, with a  tortuous learning curve [9, 10]; these issues severely  affect the enthusiasm of surgeons for performing  these operations.

To overcome the aforementioned technical bottlenecks, we have drawn upon the advantages of  radical hand-assisted laparoscopic surgery for colon  cancer [11] to perform hand-assisted laparoscopic D2  radical gastrectomy (HALG) and have developed the  unique “three-step HALG method”. To more thoroughly elucidate the advantages of the “three-step  HALG method”, in this study, systematic retrospective analyses of clinical data from obese gastric cancer  patients who received HALG, LAG, and open D2  radical gastrectomy (OG) at our center during a particular time period were conducted, and the relevant  findings were summarized.

Material and methods

General information D2

radical gastrectomy  was performed in 270 cases involving obese gastric  cancer patients at our center between July 2008 and  December 2013. HALG, LAG, and OG were performed in 54, 51, and 165 of these cases, respectively.  According to the standards established by the World  Health Organization for Asian obese patients in  2003[12] and the surgical treatment guidelines for  Chinese obese patients in 2007[13], obesity is defined  as a body mass index (BMI) ≥25 kg/m2. A study design of a non-randomized controlled trial during the  examined time period was adopted for this investigation, with surgical methods chosen based on the condition and wishes of each patient. The following case  inclusion criteria were utilized: (1) there was a definite  preoperative pathological diagnosis; (2) distal metastasis was excluded by preoperative auxiliary examinations, the tumor had not directly invaded adjacent  organs, and complete resection of the tumor appeared  to be feasible; and (3) R0 resection was confirmed by  postoperative pathological examination. Cases were  excluded if intraoperative findings revealed peritoneal dissemination of the tumor or if D2 radical surgery could not be definitively completed. General information includes patients’ ages, genders, BMI  values, American Society of Anesthesiologists (ASA)  physical status classifications[14], major associated  underlying preoperative diseases (hypertension,  pulmonary insufficiency, or diabetes mellitus), history  of abdominal surgery, tumor sizes, tumor–node–metastasis (TNM) stages, and rates of  conversion to laparotomy. All surgeries were completed by highly qualified specialists who possessed  extensive clinical experience. The same postoperative  treatment principles and discharge criteria were applied for all patients. 

Surgical methods

Tumor stages were determined based on abdominal exploration. The dissection of lymph nodes in the perigastric region and D2  radical gastrectomy were performed in accordance  with the Japanese publication “Gastric cancer treatment protocols”. Conventional OG and LAG were  mature and well-established surgical procedures  (Fig.1 E, F). The “three-step HALG method” was divided into three steps (Fig.1 A~D): hand-assisted incision surgeries under direct vision, hand-assisted  laparoscopic surgeries, and digestive tract reconstruction. The specific surgical procedures and our  preliminary work have been published in Surgical  Endoscopy [15]. 

Observation indicators

Full-time personnel at  our center completed the observation and recording  of all indicators. Intraoperative indicators included  type of surgery (total gastrectomy, proximal gastrectomy, or distal gastrectomy), operation time (total  operation time and laparoscopic operation time),  quantity of blood lost, incision length, number of  lymph nodes recovered, and unexpected intraoperative injury. Postoperative indicators included postoperative pain scores (at days 1 and 2 after surgery),  intestinal function recovery time, duration of postoperative hospital stay, complications (pulmonary infection, arrhythmia, venous thrombosis, gastrointestinal fistula, disorders of gastrointestinal function, bile  reflux, abdominal cavity infections, and wound infections), reoperation rate, readmission rate within 30  days after surgery, and mortality rate. A pathologist  and a surgeon removed lymph nodes from resected  specimens individually, which were classified by  pathological examination. Postoperative pain scores  were assessed using the visual analog scale (VAS)  [16]. Pain scores were evaluated three times per day,  and the highest score for a day was used as the day’s  pain score. Cases involving conversion to laparotomy  were not included in intraoperative and postoperative  statistics.

Statistical analysis 

The SPSS16.0 software package was used for statistical analyses. Measurement data were expressed as means±standard deviations and were analyzed by one-way analysis of variance (ANOVA),  and pairwise comparisons between groups were performed with LSD method. Count data were assessed  using χ2 tests. P <0.05 was adopted as the threshold  for significance in statistical analyses.

Figure 1. HALG for total gastrectomy (A~D): A shows that the NO. 6 lymph nodes were dissected under direct vision via auxiliary incision, and right gastroepiploic artery was transected; B shows that the  NO. 11 lymph nodes were dissected, and Splenic vessels was revealed; C shows that the NO. 7,8 and 9  lymph nodes were dissected, and Left gastric artery and hepatic artery were revealed; D shows that  NO.10 lymph nodes were dissected, and splenic hilum and splenic artery were revealed. LAG for antral  cancer (E): E shows that the NO. 5,7,8,9 and 12 lymph nodes were dissected, and Left gastric artery, hepatic artery and pancreatic duodenum artery were revealed. OG for antral cancer (F): F shows that  the NO. 5,7,8,9,11 and 12 lymph nodes were dissected, and Left gastric artery, hepatic artery and splenic  artery were revealed.

Results 

General information results

In this study, there were 54, 51, and 165 cases in  the HALG, LAG, and OG groups, respectively. The  results of statistical analyses for patients’ general information are presented in Table 1. In particular, the P values for age, gender, BMI, and ASA were 0.21, 0.16,  0.08, and 0.70, respectively. The major underlying  diseases included hypertension, pulmonary insufficiency, and diabetes mellitus; the P values for these diseases were 0.57, 0.45, and 0.57, respectively. The P values for a history of pulmonary surgery, tumor size, and the TNM  stages were 0.22, 0.13, and 0.27, respectively. Conversion to laparotomy occurred  in 1 case in the HALG group and 8 cases in  the LAG group, and P =0.03. Conversion  to laparotomy occurred for the following  reasons: 1 case in the HALG group of  massive bleeding from an injury in the left  gastric artery near the splenic hilum, 5  cases in the LAG group of intraoperative  bleeding, 2 cases in the LAG group of tumor invasion of the roots of the middle  colic artery, and 1 case in the LAG group  of invasion of the duodenum by a tumor in  the gastric antrum. None of the cases involving conversion to laparotomy were  included in the intraoperative and postoperative statistics; therefore, 53 cases in  the HALG group and 43 cases in the LAG  group were included in the intraoperative  and postoperative statistical analyses.

Results for intraoperative indicators

A total of 6 intraoperative indicators  were examined, and the results of statistical analyses are presented in Table 2. P =0.00 for comparisons of incision length  among the groups. In particular, the incision length for the HALG group was  7.04±0.19 cm, which was 1.25cm longer  than that for the LAG group and 6.82 cm  shorter than that for the OG group. P =0.73  for the comparison of type of surgery  among the experimental groups. Total  operation time for the HALG group was  179.11±16.82 min, which was 25min shorter than that  for the LAG group (P =0.00) and 8 min longer than  that for the OG group (P =0.76). Laparoscopic operation time for the HALG group was 50.92±9.89 min;  which was 119 min shorter than that for the LAG  group (P =0.00). P =0.77 for the comparison of intraoperative blood loss among the experimental  groups. The number of lymph nodes recovered for the  HALG group was 19.36±3.27, which was 3 more than  that for the LAG group (P =0.00) and 1 more than that  for the OG group (P =0.21). P =0.09 for the comparison  of unexpected injuries among the experimental  groups. In particular, there were 2 cases of such injuries in the HALG group (with unexpected injuries  occurring in 3.77% of the cases in this group), including 1 case of mesocolon injury and 1 case of minor  lacerations to the lower pole of the spleen. There were  6 cases of unexpected injuries in the OG group, with unexpected injuries occurring in 3.64% of the cases in  this group, and 5 cases of unexpected injuries in the  LAG group, with unexpected injuries occurring in  11.63% of the cases in this group.

Postoperative indicator results

A total of 7 postoperative indicators were examined, and the results of statistical analyses are  presented in Table 3. The VAS score for the HALG  group on day 1 after surgery was 5.46±1.43, which  was significantly higher than that for the LAG group  (P =0.00), but significantly lower than that for the OG  group (P =0.02). The VAS score for the HALG group  on day 2 after surgery was 4.14±1.12, which was not  significantly different from that for the LAG group (P =0.13) but was significantly lower than that for the OG  group (P =0.00). The postoperative hospital stay duration for the HALG group was 9.64±2.34 days, which  was similar to that for the LAG group (P =0.98) but  was 1 day less than that for the OG group (P =0.01).  The intestinal function recovery time for the HALG  group was 62.81±14.61 h, which was not significantly  different from that for the LAG group (P =0.80) but  was 47 h less than that for the OG group (P =0.00).

Table 1. The comparison of general data.

Table 2. The comparison of intraoperative data.

Table 3. The comparison of postoperative data.

For each individual complication, P >0.05 for  comparisons among the experimental groups. The  HALG group included a total of 5 cases of postoperative complications, with postoperative complications  occurring in 9.43% of the cases in this group; this  percentage was significantly lower than the corresponding percentages of 25.58% for the LAG group  and 24.85% for the OG group (P =0.049). In particular,  P =0.07 for the comparison of postoperative complications between the HALG and LAG groups, and P =0.03 for the comparison of postoperative complications between the HALG and OG groups. There were  3 cases of cardiopulmonary complications in the  HALG group, and such complications occurred in  5.66% of the cases in this group. In the LAG group,  cardiopulmonary complications occurred in 16.28% of  cases, and P =0.00 for the comparison of the rates of  cardiopulmonary complications between the HALG  and LAG groups. In the OG group, cardiopulmonary  complications occurred in 6.67% of cases. Postoperative gastrointestinal fistula is a severe complication (P =0.74) that occurred in 1 case (1.89%) in the HALG  group, 2 cases (4.65%) in the LAG group, and 5 cases  (3.03%) in the OG group. There were 1, 1, and 2 cases  of reoperation for peritoneal drainage in the HALG,  LAG, and OG groups, respectively. P =0.85 for the  comparison of reoperation rates among all groups.  B-mode ultrasound was used to guide the placement  of drainage tubes in patients who were not subjected  to second surgeries.

In the HALG, LAG, and OG groups, there were  2, 2, and 8 cases, respectively, of patients who were  readmitted within 30 days of the surgery; such cases accounted for 3.77%, 4.65%, and 4.85% of the cases in  each respective group (P =0.95). In the HALG group, 1  patient was readmitted due to intestinal adhesion,  and 1 patient was readmitted due to abdominal distention after eating. After these 2 patients received 2-5  days of treatment, all of their symptoms had been  relieved, and the patients were discharged. There  were no postoperative deaths in either the HALG or  the LAG groups, whereas there were 2 cases of postoperative death in the OG group (with such cases  accounting for 1.21% of this group). One patient died  due to the failure of cardiopulmonary function, and  the other patient, who was in poor general condition,  died of abdominal infection caused by poor drainage  from a gastrointestinal fistula. P =0.56 for a comparison of postoperative deaths among the experimental  groups.

Discussion

Laparoscopic techniques have produced positive  outcomes for the radical treatment of obese gastric  cancer patients, however, the following shortcomings  continue to limit the use of laparoscopic approach: (1)  laparoscopic approaches involve prolonged operation  times, resulting in fatigue among surgeons and a tortuous learning curve for these techniques[8-10]; (2) the  effects of radical laparoscopic surgery have been  questioned[17]; and (3) prolonged pneumoperitoneum aggravates cardiopulmonary burdens, leading to  increased perioperative cardiopulmonary complications[18,19]. To realize the advantages but avoid the  disadvantages of laparotomies and laparoscopies, we  developed the unique “three-step HALG method”. Through systematic retrospective analyses and summarization of the clinical data from all patients of this  study, we believe that the “three-step HALG method”  has unique advantages for obese gastric cancer patients and is an extremely viable option for the surgical treatment of these patients.

The unique advantages of auxiliary incision for  the “three-step HALG method”

The laparoscopic procedures of LAG surgery  can be unusually difficult in cases involving obese  patients because the greater omentum occupies a  large volume of space in the upper abdomen [8].  However, HALG begins by creating an incision below  the xiphoid process. This incision not only is used for  hand-assisted laparoscopic operations, tissue removal, and digestive tract reconstruction but also provides  the unique advantage of enabling partial tissue separation and perigastric lymph node dissection to be  completed under direct vision. The incision created  using a hand-assisted device with a blue butterfly  base can fully expose the local operative field. First,  the transverse colon and the greater omentum are  lifted outside the incision; the greater omentum is  then fully freed and removed and this removal allows  for the fuller and clearer exposure of the operative  field under direct vision. The surgery continues by  freeing the anterior lobe of the transverse mesocolon,  part of the pancreatic capsule, and the duodenal bulb.  Dissection is then performed on the lymph nodes in  groups 5, 6, 12a, and 14v and a portion of the lymph  nodes in group 8a.This approach greatly reduce  pneumoperitoneum and laparoscopic operation time.

When completed the first step, the upper abdominal space is largely released and surgeons can  more freely conduct left hand-assisted operations in  the second step of the surgery. Surgeon can use the  sensitive direct touch of the left hand and can achieve  separation with the assistance of ultrasonic scalpels;  as a result, the separation of major blood vessels and  lymph node dissection can be more easily accomplished. During LAG surgery, the dissection of the  lymph nodes in groups 7, 8, 9, 10, and 11p presents  operational difficulties[20-22]. During the HALG  surgery, the assisting hand fully exposes the operative  field, and the thumb and index finger can directly  touch and protect major blood vessels and tissues  wrapped in fat tissue, providing important advantages in the dissection of the region from the lesser  curvature of the stomach and the splenic artery to the  splenic hilum and the gastric cardia. Therefore, there  is significantly less difficulty and risk involved in the  surgical procedure for HALG than for LAG.

The thoroughness of radical treatment for the “three-step HALG method”

The number of dissected perigastric lymph  nodes is an important criterion for measuring the  thoroughness of radical treatment [23, 24]. In this  study, the number of dissected lymph nodes was  smaller than that in previous studies [25], which were  possible associated with that the other authors used  lymphatic tracer during surgery, or our way of harvested lymph nodes from specimen need to be improved. In this study, similar numbers of lymph  nodes were recovered for both the HALG and OG  groups (P =0.21). The number of lymph nodes recovered for the LAG group was 3 nodes fewer than that  for the HALG group (P =0.00). Therefore, we believe  that the HALG approach was more thorough than the  LAG approach. The reasons maybe as follow: the  lymph node groups 6, 7, 8a, 9, 10, and 11 are in close  proximity to major blood vessels which are encapsulated by fat tissues, and severe unexpected injuries  can readily occur during lymph node dissection;  therefore, significant difficulties will accompany with  LAG surgery [20-22]. In HALG surgery, dissection of  lymph nodes in group 6 and a portion of 8a can be  conducted under direct vision. In addition, during the  laparoscopic portion of the HALG surgery, the tactile,  exposure, and protection roles of the hands can be  completely fulfilled; therefore, the separation and  cutting functions of ultrasonic scalpels can be fully  realized, and the complexity of surgical procedures  can be significantly reduced. As a result, relatively  thorough lymph node dissection can be achieved.

The minimal invasiveness for the “three-step  HALG method”

The question of whether hand-assisted laparoscopic surgery is minimally invasive with respect to  damage to the body remains unresolved in the extant  literature [26, 27]. We believe that HALG causes fewer  traumas than OG and exhibits the same minimal invasiveness as LAG. (1) The incision length for the  HALG group significantly shorter than that for the  OG group (P =0.00), and only 1.25cm longer than that  for the LAG group. (2) Pneumoperitoneum time for  the HALG group was much lower than that for the  LAG group (P =0.00). Because of this prolonged  pneumoperitoneum time, there were significant compression effects on the hearts and lungs of obese  patients in the LAG group, and increased postoperative cardiopulmonary complications were a direct  result of this issue [18, 19]. (3) The VAS scores for the  HALG group on day 2 after surgery did not differ  from that for the LAG group (P =0.13), but remained  significantly lower than that for the OG group (P =0.00). These findings indicated that similar levels of pain control were achieved for HALG and LAG. (4)  Intestinal function recovery time and duration of  postoperative hospital stay did not significantly differ  for the HALG and LAG groups (P >0.05) but were  significantly shorter for the HALG group than for the  OG group (P <0.05).These results suggested that with  respect to abdominal organs, HALG and LAG were  significantly less intrusive than OG.

The safety for the “three-step HALG method”

The disturbance, traction and the compression of  the thoracic cavity by pneumoperitoneum during  surgery are the important elements of trauma [28].  Studies have demonstrated that trauma is closely associated with the stability of the internal environment  [29, 30]. Obese patients suffer from many underlying  diseases and exhibit reduced cardiopulmonary function and operational tolerance; thus, their internal  environment is relatively sensitive to trauma [31]. In  this study, HALG significantly shorten pneumoperitoneum time. Therefore, HALG is a relatively safe  surgical approach. (1) The rates of unexpected intraoperative injuries in the HALG and OG groups  were markedly lower than that in the LAG group. (2)  The rate of complications in the HALG group was  significantly lower than that in the LAG and OG  groups (P =0.049). In-depth analyses revealed that the  percentage of cases involving postoperative cardiopulmonary complications was significantly lower for  the HALG group than that for the LAG group (P =0.00). (3) There was one case of conversion to laparotomy in the HALG group; which was markedly  lower than the corresponding percentage for the LAG  group (P =0.03). These results indicated that the assisting hand in the HALG surgery played important  roles in protecting, dissecting, and separating critical  fat-encapsulated structures, resulting in better control  of surgery-related injury. (4) There were no significant  differences among the experimental groups with respect to quantity of blood lost, reoperation rate, or  readmission rate within 30 days after surgery (P >0.05).

Abbreviations

HALG: hand-assisted laparoscopic D2 radical  gastrectomy

LAG: laparoscopic-assisted D2 radical gastrectomy

OG: open D2 radical gastrectomy 

BMI: obesity is defined as a body mass index  

ASA: American Society of Anesthesiologists  

TNM: tumor–node–metastasis

Competing Interests 

The authors have declared that no competing  interest exists.

References

1. Harris AT, Morell D, Bajaj Y, et al. A discussion of airway and respiratory  complications along with general considerations in obese patients. Int J Clin  Pract. 2010;64:802-6. 

2. Kunisaki C, Makino H, Takagawa R, et al. Predictive factors for surgical  complications of laparoscopy-assisted distal gastrectomy for gastric cancer.  Surg Endosc. 2009;23:2085-93. 

3. Kim MG, Kim KC, Kim BS, et al. A totally laparoscopic distal gastrectomy can  be an effective way of performing laparoscopic gastrectomy in obese patients  (body mass index≥30). World J Surg. 2011;35:1327-32. 

4. Lee MS, Lee JH, Park do J, et al. Comparison of short- and long-term outcomes  of laparoscopic-assisted total gastrectomy and open total gastrectomy in gastric cancer patients. Surg Endosc. 2013;27:2598-605. 

5. Meng H, Zhou D, Jiang X, et al. Incidence and risk factors for postsurgical  gastroparesis syndrome after laparoscopic and open radical gastrectomy.  World J Surg Oncol. 2013 ;11:144.

6. Sugimoto M, Kinoshita T, Shibasaki H, et al. Short-term outcome of total  laparoscopic distal gastrectomy for overweight and obese patients with gastric  cancer. Surg Endosc. 2013;27:4291-6.

7. Kim MG, Kawada H, Kim BS, et al. A totally laparoscopic distal gastrectomy  with gastroduodenostomy (TLDG) for improvement of the early surgical  outcomes in high BMI patients. Surg Endosc. 2011;25:1076-82. 

8. Miyaki A, Imamura K, Kobayashi R, et al. Impact of visceral fat on laparoscopy-assisted distal gastrectomy. Surgeon. 2013;11:76-81. 

9. Yoshikawa K, Shimada M, Kurita N, et al. Visceral fat area is superior to body  mass index as a predictive factor for risk with laparoscopy-assisted gastrectomy for gastric cancer. Surg Endosc. 2011;25:3825-30. 

10. Zhou D, Quan Z, Wang J, et al.Laparoscopic-assisted versus open distal  gastrectomy with D2 lymph node resection for advanced gastric cancer: effect  of learning curve on short-term outcomes. a meta-analysis. J Laparoendosc  Adv Surg Tech A. 2014;24:139-50.

11. Meshikhes AW. Controversy of hand-assisted laparoscopic colorectal surgery.  World J Gastroenterol. 2010;16:5662-8.

12. Choo V. WHO reassesses appropriate body-mass index for Asian populations.  Lancet. 2003;361:85. 

13. Zheng CZ. The surgical treatment guidelines for Chinese obese patients. Chin  J Pract Surg. 2007;27:759-62. 

14. Tan WP, Talbott VA, Leong QQ, et al. American Society of Anesthesiologists  class and Charlson's Comorbidity index as predictors of postoperative colorectal anastomotic leak: a single-institution experience. J Surg Res.  2013;184:115-9. 

15. Gong JQ, Cao YK, Li YM, et al. Hand-assisted laparoscopic vs. laparoscopy-assisted D2 radical gastrectomy: a prospective study. Surg Endosc. 2014;  28:2998-3006. 

16. Aicher B, Peil H, Peil B, et al. Pain measurement: Visual Analogue Scale (VAS)  and Verbal Rating Scale (VRS) in clinical trials with OTC analgesics in headache. Cephalalgia. 2012;32:185-97. 

17. Lee HJ, Kim HH, Kim MC, et al. The impact of a high body mass index on  laparoscopy assisted gastrectomy for gastric cancer. Surg Endosc.  2009;23:2473-9.

18. Gaszynski T, Szewczyk T. The influence of laparoscopic vs. open gastric  bypass on hemodynamic function in morbidly obese patients during general  anesthesia. Wideochir Inne Tech Malo Inwazyjne. 2014;9:83-8. 

19. Almarakbi WA, Fawzi HM, Alhashemi JA. Effects of four intraoperative  ventilatory strategies on respiratory compliance and gas exchange during  laparoscopic gastric banding in obese patients. Br J Anaesth. 2009;102:862-8. 

20. Huang CM, Lu J. Strategy and prospect of laparoscopic lymph node dissection  for locally advanced upper-third gastric cancer. Zhonghua Wei Chang Wai Ke  Za Zhi. 2013;16:930-2. 

21. Kong J, Wu SD, Su Y. Translumenal single-incision laparoscopy radical gastrectomy with D2 lymph node dissection for early gastric cancer--primary  experience with less invasive surgery in China. J Laparoendosc Adv Surg Tech  A. 2013;23:141-5.  

22. Li Y, Wang J. Station 10 lymph node dissections in laparoscopic-assisted  spleen-preserving radical gastrectomy for advanced proximal gastric cancer.  Chin J Cancer Res. 2013;25:465-7. 

23. Medina-Franco H, Cabrera-Mendoza F, Almaguer-Rosales S, et al. Lymph  node ratio as a predictor of survival in gastric carcinoma. Am Surg.  2013;79:284-9.

24. Chen S, Zhao BW, Li YF, et al. The prognostic value of harvested lymph nodes  and the metastatic lymph node ratio for gastric cancer patients: results of a  study of 1,101 patients. PLoS One. 2012;7:e49424. 

25. Lee HJ, Kim HH, Kim MC, et al. The impact of a high body mass index on  laparoscopy assisted gastrectomy for gastric cancer. Surg Endosc.  2009;23(11):2473-9. 

26. Kim H. Should hand-assisted laparoscopic surgery be placed in the realm of  minimally invasive surgery? Ann Coloproctol. 2013;29:42-3.

27. Patel CB, Ragupathi M, Ramos-Valadez DI, et al. A three-arm (laparoscopic,  hand-assisted, and robotic) matched-case analysis of intraoperative and  postoperative outcomes in minimally invasive colorectal surgery. Dis Colon  Rectum. 2011;54:144-50. 

28. Schietroma M, Carlei F, Cecilia EM, et al. A prospective randomized study of  systemic inflammation and immune response after laparoscopic nissen fundoplication performed with standard and low-pressure pneumoperitoneum.  Surg Laparosc Endosc Percutan Tech. 2013;23:189-96.

29. Pierce A, Pittet JF. Inflammatory response to trauma: implications for coagulation and resuscitation. Curr Opin Anaesthesiol. 2014;27:246-52. 

 30. Ross C, Byard RW, Langlois NE. Does the intensity of the inflammatory  reaction in a bruise depend on its proximity to the site of trauma? Forensic Sci  Med Pathol. 2013;9:358-62. 

31. Winfield RD, Delano MJ, Dixon DJ, et al. Differences in outcome between  obese and nonobese patients following severe blunt trauma are not consistent  with an early inflammatory genomic response. Crit Care Med. 2010;38:51-55.