Further information on the physics and actions of lasers, ultrasonic shears, and staplers is available.10,11
Obesity may increase the risk of major vessel injury
A recent study by Baggish found obesity to be a high-risk circumstance for major vessel injury.12 In the study, 22 of 31 women who sustained injury were overweight or obese, with a BMI ranging from 26 to 30 kg/m2.
Obesity increases the risk of major vessel injury because of the greater elasticity of the anterior abdominal wall. As force secondary to the downward thrust of the trocar is placed on the abdominal wall, it is pushed inward in the direction of the posterior wall. In contrast, thin women have rigid abdominal walls with minimal elasticity, so the force of the trocar thrust does not create significant displacement.
Baggish also found that disposable trocars accounted for 90% of major vascular injuries and that use of long trocars accounted for 43% of deaths.12
Injury and death are rare but real risks
In a multicenter study in France over 9 years, investigators reviewed 29,966 diagnostic and operative laparoscopic procedures and found a mortality rate of 3.33 deaths for every 100,000 laparoscopies and an overall complication rate of 4.64 complications for every 1,000 procedures.13 They found the complication rate to be significantly correlated with the complexity of the procedure (P = .0001). One in three complications (34.1%; n = 43) occurred during set-up, and one in four (28.6%) were not identified intraoperatively.13
The risk of great vessel injury associated with laparoscopy most frequently quoted is 0.5 injury for every 1,000 procedures.14 A multicenter study reported the prevalence of this complication to be 1.05 injuries per 1,000 procedures.15
The mortality rate associated with major vessel injury has been reported in several studies to range from 8% to 17%.14-17
Two articles measured the distance from various points on the anterior abdominal wall to the great retroperitoneal vessels during laparoscopic operations; they also measured the force required for the trocar to penetrate the abdominal wall.18,19 They found significant differences in the distance from the site of primary trocar insertion to the aorta and iliac vessels, depending on the BMI of the patient. In women with a BMI below 25 kg/m2, the mean distance to the aorta was 11.21 cm. In women with a BMI of 25 to 30, it was 14.14 cm, and in women with a BMI over 30, it was 15.14 cm. They also found variations in the mean thickness of the abdominal wall, which was 3.48 cm, 3.85 cm, and 5.05 cm in women with a BMI of less than 25, 25–30, and more than 30, respectively.
As for the force required for entry, investigators found that disposable cutting trocars can traverse the anterior abdominal wall with less force and less time, compared with reusable trocars and optical viewing devices.18,19
Another study measured the thickness of the abdominal wall and the distance to the great vessels by magnetic resonance imaging or computed tomography.20 However, this study was not performed during laparoscopy with pneumoperitoneum in place.
As previously mentioned, Baggish reported on 31 cases of major-vessel injury associated with laparoscopic operations involving 49 major-vessel injuries. Twenty-eight injuries occurred as a result of entry techniques: 26 occurred during primary trocar insertion, and two were related to secondary trocar thrusts.12 Four injuries and three deaths were associated with use of an 11-inch disposable trocar.
Of the injuries associated with primary trocar insertion, 10 occurred during direct insertion and 26 after creation of pneumoperitoneum. Open laparoscopy was performed in two cases.12 The TABLE details the number of vessels injured and the sites of injury in this study.
Seven women (23%) died as a direct result of venous injury. Collateral injury to other structures was observed in 16 cases. Blood loss ranged from 1,000 mL to 7,000 mL.12
Sites of major vessel injury in one study of gynecologic laparoscopy
| Site | Number of vascular injuries |
|---|---|
| Right iliac artery | 14 |
| Right iliac vein | 12 |
| Left iliac artery | 3 |
| Left iliac vein | 9 |
| Aorta | 4 |
| Vena cava | 2 |
| Mesenteric | 2 |
| Interior epigastric* | 2 |
| Other | 1 |
| Total injuries | 49 |
| Source: Baggish12 | |
Avoid these common errors
The most common errors in gynecologic laparoscopy include:
- delayed diagnosis
- failure to act on a visible retroperitoneal hematoma
- failure to cross-match adequate supplies of blood and blood products
- failure to adequately transfuse blood and blood products
- clamping the large damaged vessel
- opening the abdomen via Pfannenstiel incision
- failure to call for a vascular surgeon in a timely manner.
When a major vascular injury occurs, a well-informed surgeon will take the following measures:
- call for a vascular surgeon immediately. (Baggish found that there was a substantial delay in getting a vascular surgeon to the operating table in four of 31 cases.12)
- open the abdomen via a midline incision
- use a sponge stick to apply direct pressure to the bleeding vessel
- obtain an emergency type and cross-match and order a minimum of 6 U of blood plus fresh frozen plasma
- obtain a baseline complete blood count, platelet count, fibrinogen level, and test for fibrin-split products
- advise the anesthesiologist to seek additional help
- call for additional OR nursing personnel
- assign one circulator to run stats and record critical data.21-33