Dr.Mohammad foudaziResearch center of endoscopic

surgery , Iran medical university

Bariatric surgery is increasing in North America. In a population-based study, Pope et al, reported that the number of bariatric procedures performed in the United States increased from 4,925 operations in 1990 to 12,541 operations in 1997, then increased sharply to 70,256 procedures in 2002. Although the first case series of laparoscopic gastricbypasses (GBPs) was reported in 1994, the dissemination of the laparoscopic approach did not occur until 1999.

The high demand for minimally invasive bariatric surgery combined with increase in surgeons who are skilled in the technique demands a clear understanding of the evidence-based data on which the safety of minimally invasive bariatric surgery is based.

current scientific rationale for the use of minimally invasive technique in bariatric surgery.

laparoscopic bariatric surgery was introduced as an alternative to open bariatric surgery.open bariatric surgery can be performed with a good outcome, but the wound-related complications such as:

1.Infection (15%) 2.late incisional hernia (up to 20%)

can be troublesome.

The laparoscopic approach benefit1.Minimize the access incision2.reduction in postoperative pain3.shorter length of hospital stay4.faster recovery.

Large clinical series have demonstrated the safety and efficacy of laparoscopic GBP; three prospective, randomized trials comparing laparoscopic versus open GBP 1.The first randomized trial reported by Westling et al involved 51 patients (laparoscopic= 30, open = 21).The results of this small trial are difficult to interpret because of the author’s high conversion rate from laparoscopic to open procedures (23%),

2. The second prospective, randomized trial was published by Nguyen et al. in 2001

3. The last trial was published by a group

from Murcia, Spain, in 2004.

The results from these two trials will be considered in detail in the following section

OUTCOMES OF LAPAROSCOPIC VERSUSOPEN GASTRIC BYPASS

By reducing the size of the access incision and therefore operative trauma to the host, minimally invasive bariatric surgery has physiological advantages over open bariatric surgery.

post operative pulmonary function:Nguyen and colleagues demonstrated significantly less impairment of postoperative pulmonary function after the laparoscopic procedure.

The forced expiratory volume at 1 second was 38% higher on the first postoperative day after laparoscopic than after open GBP.There was also a lower rate of segmental atelectasis after laparoscopic GBP.

Postoperative PainThe magnitude of postoperative pain is often a reflection of the extent of the surgical incision and operative trauma associated with the procedure.

Postoperative pain is significantly less after laparoscopic GBP.

Weight lossThe primary difference between the two techniquesis in the method of access and not the gastrointestinal (GI)anatomic construction. Short-term weight loss, however, appears to be better if the patient has had a minimally invasive approach. In Nguyen’s randomized trial of laparoscopic versusopen GBP,at 6 month 54% vs 45%, at 1 year 68% vs 62%.

Courcoulas et al., at 6 months 52% vs 45%at 1 year 69% vs 65%

is probably due to the earlier resumption of physical activities and initiation of an exercise program as these patients experienced a shorter recovery time.

COMPLICATIONS OF LAPAROSCOPICVERSUS OPEN GASTRIC BYPASS

The development of any new laparoscopic

operations can be associated with a “learning curve.” Mastering the technique of laparoscopic GBP often requires between 75 and 100 cases.

Leak

In a review of the literature between 1994 and 2002,Podnos et al,. Reported: 1.7% for open GBP (range, 0.5%–6.1%) 2.1% for laparoscopic GBP (range, 0.9%–4.3%). : may represent the “learning curve” of the laparoscopic procedure.Wittgrove and Clark reported 9 anastomotic leaks (3.0%) in their first 300 laparoscopic GBP procedures and only 2 leaks (1.0%) in their last 200 laparoscopic GBP procedures. In contrast, Higa et al reported a 0.3% incidence of anastomotic leak in 1,500 laparoscopic GBP procedures, demonstrating that anastomotic leak can be low when performed by an experienced surgical team.

Wound ComplicationsThe incidence of wound infection after minimally invasive bariatric surgery is lower than that of open bariatric surgery.GBP (1.3% vs 10.5%).reduced incidence of late incisional hernia, (as high as 20% after open).Podnos et al ; incisional hernia (8.6% vs 0.5%).

wound dehiscence and evisceration have been completely eliminated in minimally invasive bariatric surgery.

Courcoulas et al reported a 7.5% incidence of wound dehiscence after open GBP compared to none after laparoscopic GBP.

Retained foreign bodyThe risk of retained instruments and sponges is essentially eliminated with the laparoscopic approach as it is impossible to insert these items through the trocar.

In Nguyen’s randomized trial of laparoscopic versus open GBP, a retained laparotomy sponge occurred in one patient in the open group.

Bowel Obstruction One of the potential benefits of minimally invasive bariatric surgery is the reduction of adhesions.

Podnos et al reported that the frequency of both early and late postoperative bowel obstruction was higher after laparoscopic GBP. late bowel obstruction is higher after laparoscopic compared to open GBP (3.1% vs 2.1%) internal herniation

Gastrointestinal HemorrhageThe source of postoperative GI bleeding is

1.gastric remnant, 2.Gastrojejunostomy,3. jejunojejunostomy staple-lines. The frequency of postoperative GI hemorrhage is higher after laparoscopic than after GBP (1.9% vs 0.6%),

which may be related to 1.aggressive use of anticoagulants for deep venous

thrombosis prophylaxis, 2. the frequent use of a stapled gastrojejunostomy, 3. less frequent oversewing of staple-lines.

Anastomotic strictureno significant difference in stomal stenosis rate (24% vs 20%) between the two techniques.

1.technical factors such as tension or ischemia 2.techniques for construction of the anastomosis

such as the use of mechanical stapler versus hand-sewn. Gonzalez et al reported:the circular stapler technique has the highest rate of stricture (31%) compared to hand-sewn (3%) or linear stapler (0%) technique

MortalityThe mortality after minimally invasive bariatric surgery appears to be similar or lower than that of open bariatric surgery.

Podnos et al reported a lower rate of mortality after laparoscopic compared to openGBP(0.23% vs 0.87%, respectively).

CONCLUSIONS The fundamental differences between minimally

invasive bariatric surgery and open bariatric surgery are

1.the methods of abdominal wall access2.operative exposure By reducing the size of the surgical incision and

the trauma associated with the operative exposure, the physiologic insult is less in minimally invasive bariatric surgery

• Advantages of minimally invasive bariatric surgery include:

1. less impairment of postoperative pulmonary function and pulmonary atelectasis.

2.lower operative blood loss,3. a shorter hospital stay, 4.Reduction in postoperative pain5.faster recovery.• The main disadvantage of the laparoscopic approach

is the steep learning curve, which may require experience in as much as 100 operations to overcome.