Vascular and Bowel Injuries During Laparoscopy

 

David Anaise MD JD discusses common reasons for vascular and bowel injuries during laparoscopy.

ACKNOWLEDGEMENT

This article is based largely on the following articles. The readers are encouraged to read these excellent articles in their totality.

Paul Lin MD Daniel R. Grow MD COMPLICATIONS OF LAPAROSCOPY Obstetrics and Gynecology Clinics Volume 26 • Number 1 • March 1999

Abdominal access complications in laparoscopic surgery Philips PA, Amaral JF Journal of the American College of Surgeons – April 2001 (Vol. 192, Issue 4)

Trocar injuries in laparoscopic surgery Bhoyrul S, Vierra MA, Nezhat CR, Krummel TM, Way LW

Journal of the American College of Surgeons – June 2001 (Vol. 192, Issue 6)

Major vascular injuries during gynecologic laparoscopy Chapron CM, Pierre F, Lacroix S, Querleu D, Lansac J, Dubuisson JB Journal of the American College of Surgeons – November 1997 (Vol. 185, Issue 5)

Myriam J. Curet MD SPECIAL PROBLEMS IN LAPAROSCOPIC SURGERY Surgical Clinics of North America Volume 80 • Number 4 • August 2000

INTRODUCTION

Abdominal access and the creation of a pneumoperitoneum carry a significant risk of bowel and vascular injuries. Such injuries are unique to laparoscopic surgery and are avoided in an open surgery. Although these catastrophic injuries are uncommon, they represent a major reason for mortality from laparoscopic procedures, and a significant source of the morbidity associated with any laparoscopic procedure. Shea and colleagues examined 78,747 patients in a meta-analysis of 98 laparoscopic cholecystectomy studies. Fourteen percent of 1,400 conversions were from complications such as bleeding and bowel injury.

Despite the rapid evolution of laparoscopic surgery in the past decade, the surgical community has failed to adequately report and study this tragic complication. As a result, most case reports and large series reporting these injuries are derived from older gynecologic literature. It was largely believed that that newer instrumentation and knowledge would reduce the risk of these complications, reports from the general surgical literature, however, suggest this not to be the case. In fact, these injuries occur with greater frequency. Most disturbing, surgeons have been oblivious to the risk of trocar injury by failing to associate post operative complication with the possibility of trocar injury and thus failing to recognize bowel perforation until it is too late. Laparoscopic cases are scheduled in out patient clinics lacking blood, vascular operative instruments and expertise. Rarely does this complication addressed in the informed consent beyond the customary and conclusionary ” bleeding and infection”

 

Vascular injuries

Major vascular injury during the initiation of pneumoperitoneum is a much-feared complication of laparoscopic procedures. Vascular injury is a major cause of death from laparoscopy, with a reported mortality rate of 15%. Major vascular injury can occur when the Veress needle is inserted prior to insufflation, or when a trocar is inserted after insufflation.

The reason for these injuries is the close proximity of the anterior abdominal wall to the retroperitoneal vascular structures. In thin people, this distance can be as little as 2 cm. The distal aorta and right common iliac artery are particularly prone to injury. This is not surprising, given the fact that the take off of the right common iliac artery lies directly below the umbilicus.

Minor vascular injuries are so named because they are injuries to vessels of lesser importance than the aorta, inferior vena cava, and iliac vessels. It is not because these injuries are minor in nature. By far the most common minor vascular injury is to the inferior epigastric vessels. Injury to these vessels is reported to occur in up to 2.5% of laparoscopic hernia repairs. There were 76 cases of minor vascular injuries involving principally the epigastric vessels identified in a review of 10,837 patients undergoing hernia operation. Injuries of the epigastric vessels can be related to carelessness during the operative procedure. These injuries invariably occur during placement of secondary cannulas, which should be placed under direct vision and with prior transillumination of the abdominal wall. Although injury of the epigastric vessels is still possible if these measures are taken, the incidence should be dramatically reduced.

 

BOWEL INJURIES

Bowel injury is the third cause of death from a laparoscopic procedure after major vascular injury and anesthesia. Unlike major vascular injuries where the risk and presentation are immediate, many bowel injuries go unrecognized at the time of the procedure. Consequently, patients present postoperatively, often after discharge, with peritonitis. This delay makes it a significant cause of morbidity and mortality.

A large survey of nearly 37,000 gynecologic laparoscopies in the US revealed a 0.16% incidence of bowel injury. 39.8% of vascular and intestinal injuries were caused by the Veress needle, 37.9% by insertion of the primary trocar, and 22% by the secondary trocar. The remaining gastrointestinal injuries resulted during dissection, electrocoagulation, or grasping. Importantly, these investigators noted the experience of the surgeons was an important factor in the overall complication rate and in the incidence of intestinal injury. This is consistent with the work of Mintz, in which complications decreased with experience.

 

PREVENTION OF MAJOR VISCERAL AND VASCULAR INJURIES DURING INITIATION OF PNEUMOPERITONEUM

 

Veress needle technique

Blind Veress needle insertion and insufflation followed by blind trocar insertion is the technique most widely used. One-third to one-half of major intra-abdominal vascular and intestinal injuries occur from the Veress needle itself.

The Veress needle consists of a blunt-tipped, spring loaded inner stylet and a sharp outer needle. The stylet retracts during passage of the needle through the abdominal layers, to allow penetration. Once the peritoneum is entered, the lack of tissue resistance allows the blunt stylet to protrude. Theoretically, this should prevent perforation of intra-abdominal structures. But it is important to note that the stylet does not lock once it protrudes. It can penetrate an intra-abdominal structure because the stylet will again retract on contact with an intra-abdominal structure.

Important procedural steps during insertion of the Veress needle are:

Trendelenburg position, elevation of the abdominal wall, and direction of the needle at 45° to the spine and aimed toward the pelvis in the midline. The following tests should be done to confirm the presence of the needle in the peritoneum and not in a visceral organ.

1.Manometer test–involves connecting the gas tubing to the Veress needle and raising the abdominal wall to create negative pressure.

2.. Hissing sound test–involves turning the valve to the off position after it has been properly positioned. The abdomen is elevated and the valve opened, creating a hissing sound.

3.Aspiration test–involves attaching a syringe filled with saline to the Veress needle and attempting to aspirate any material. If material is aspirated, such as bowel contents or urine, the Veress needle should be removed. If blood is removed, the needle is left in place, and preparation for exploratory laparotomy is made for a presumed vascular injury.

4. If no material is removed, 5 mL of saline is inserted, and a reattempt to aspirate is made. If no fluid is removed, entry into the peritoneal cavity is confirmed. If the saline is removed, an enclosed space was probably entered, that is, preperitoneal space, and the needle should be repositioned.

5. Hanging drop test–involves placing a drop of water on the open end of the Veress needle. The abdominal wall is elevated; if the needle is correctly positioned, the water should disappear down the shaft. Until confirmation of proper position of the needle, insufflation should be low at a rate of 1 L/minute.

 

6.. Finally, the needle is attached to an insufflator that measures the pressure at the tip. The pressure will be low (,5mmHg), if it is appropriately placed. Insufflation to 12 to 15mmHgwith carbon dioxide gas follows.

Once this pressure is achieved, a 10-mm trocar with or without a safety shield is placed blindly into the abdomen. It must be emphasized that a full pneumoperitoneum should be established prior to insertion of the blind umbilical trocar. Once again, care must be taken to elevate and stabilize the abdominal wall, and to ensure that the trocar is inserted in the midline at 45 degrees to the spine aimed towards the pelvis.

 

Open laparoscopy

In general, trocar injuries to abdominal viscera occur 1) when the viscera are unusually close to the point of trocar insertion or 2) where the trocar penetrates too far into the abdominal cavity as it is inserted. The first of these situations can be anticipated when the patient has had a previous operation. The best way to avoid visceral injury in this case is to use the open Hasson technique or, if the closed technique is used, to place the first trocar at a site remote from the previous incision.

The concept in the open technique is to create a tiny incision, directly incise the layers of the abdominal wall, directly cut the peritoneum, and enter the abdomen. Since gas can escape around the incision, an olive is placed over the end of the trocar to occlude the incision and sutures are placed on the abdominal fascia and attached to the cannula. Proposed advantages for the open technique are avoidance of blind puncture with a needle and subsequent trocar, certainty of establishing a pneumoperitoneum, and correct anatomical repair of the abdominal wall incision. In general, widespread use of this technique has been limited to patients with previous lower abdominal surgery, pregnant patients, children, and very thin patients where little space exists between the abdominal wall and the spine. Reasons for limiting the use of the open technique include greater time needed for performance, difficulty with the technique ,obesity of the patient, and difficulty maintaining the pneumoperitoneum, ,

There are considerably fewer reports of bowel and major vascular injury in the literature using this technique than the Veress needle technique. Penfield noted a 0.06% incidence of of bowel injury but the injuries were mostly partial and were recognized immediately because of the proximity of the bowel to the wound.

Manufacturers are required to report medical device-related incidents to the Food and Drug Administration. In the largest series for bowel and vascular injuries caused by trocars, Bhoyrul et al analyzed the 629 trocar injuries reported from 1993 through 1996. They reported 408 injuries of major blood vessels and 182 other visceral injuries (mainly bowel injuries). Of the 32 deaths, 26 (81%) resulted from vascular injuries and 6 (19%) resulted from bowel injuries. None of the injuries reported occurred in the open technique.

Hasson presented his review of 5284 patients who had open

laparoscopies developed complications related to primary access. Twenty-one had minor wound infections, four had minor hematomas, one developed an umbilical hernia that required reoperation, and one had an inadvertent injury to the small bowel that was repaired intraoperatively without adverse outcome. Access to the abdominal cavity was generally secured in 3-10 minutes.

In a review of 15,279 laparoscopic cases in Japan, a 1.02% incidence of needle and trocar insertion-related complications was noted, The Japanese researchers concluded in their paper that complications related to needle and trocar insertion are preventable by placement under direct vision.

proponents of the open technique often cite a lack of major vascular injuries reported in the literature. But a recent report notes two cases of aortic injury using open laparoscopy. In this regard, it is important to note that the injuries resulted from a faulty cannula and not from the technique itself. Bowel injuries reported have been minor and were recognized immediately as they were in the immediate proximity to the cannula. Nonetheless, injuries can and do occur. Measures must be taken to prevent or minimize this risk.

 

Optical trocar

The optical trocar is a new and intriguing device. The abdominal wall layers are visualized on the television monitor and cut under vision by advancement of the edge of the cannula, which is surgically sharp or conical. In such a manner, the surgeon watching on the television screen watches the blade cut the layers, allowing the surgeon to go through the peritoneum in a clear area where there is no bowel. Review of the FDA Manufacturer Device Reports reveals a number of vascular and visceral injuries with the Visiport in the presence or absence of a prior pneumoperitoneum In contrast no reports have been made for the Optiview system. Jirecek et al reviewed their experience with 1500 patients. Abdominal access was obtained via a veress needle or the Optiview system. . In the Optiview insertion group, no major

complications such as intestinal or vascular lesions were observed. In contrast, severe complications occurred on five occasions (0.5%) in the patient group undergoing blind insertion with the primary umbilical trocar, (p < 0.05, CI 0.2–1.2%).

PREVIOUS ABDOMINAL SURGERY

Originally, patients with previous abdominal surgery were recommended not to undergo laparoscopy because of the increased risk for penetrating bowel injury caused by needle or trocar insertion through bowel adhered to the abdominal wall. Formation and extent of adhesions are unpredictable. Previous surgery is clearly a risk factor for adhesion formation. Autopsy studies have found adhesions in 75% to 90% of patients with previous abdominal surgery, typically localized to the previous surgical site but often involving other areas. Interestingly 10% of patients with no previous abdominal surgery had adhesions in areas at risk for injury. Brill et al studied Three hundred sixty women undergoing operative laparoscopy after a previous laparotomy. Patients with prior midline incisions had significantly more adhesions (58 of 102) than those with Pfannenstiel incisions (70 of 258). However,the presence of adhesions in patients with previous obstetric surgery was not affected by the type of incision. . Twenty-one women, 28% of the group suffered direct injury to adherent omentum and bowel during the laparoscopic procedure.

Adhesions may be right under a scar or may be further away. Some investigators have recommended preoperative sonographic mapping of adhesions to help to determine a safe site for trocar insertion. Clearly, a midline incision presents a high risk for bowel adhesions under a planned umbilical trocar site; however, even scars away from the umbilicus can lead to adhesions at the umbilical site.

A blind-access technique (i.e., Veress needle insertion followed by trocar insertion) has resulted in a high rate of complications, even in patients without abdominal surgical scars. Most vascular injuries are associated with a blind-insertion technique of the first port, whereas more than half of all bowel injuries are associated with this technique. The risks for bowel injury or vascular injury are even higher if the needle or trocar is blindly placed through a previous incision.

Safer alternatives include placement of the needle at a site far from previous scars, such as the right upper quadrant in patients with pelvic surgery. An attempt should be made to place the needle and initial trocar in a site to be used for surgery, but occasionally access must be in a remote quadrant, such as the left subcostal region for laparoscopic cholecystectomy. The chosen site should be away from

scars and should avoid the inferior epigastric vessels. Placement in the midclavicular line is safest in the upper quadrants. In the lower abdomen, the trocars are best placed lateral to the epigastric vessels but sufficiently medial to prevent colonic injury.

Another alternative is the use of an open technique (Hasson), which allows for the identification of adherent bowel with dissection of the bowel away from the abdominal wall. Many surgeons use an open technique routinely, even in patients without previous abdominal surgery, because of the decreased risk for visceral or vascular injury. These injuries are not completely eliminated by this technique, but their prevalence is decreased with its use. In addition to decreasing the rate of bowel injury, the open

technique allows surgeons to promptly identify and repair any injury that may occur, thus decreasing morbidity and mortality rates.   Alternative sites may be used for access with the open or blind-access techniques. One advantage of placing the first port in a site away from previous scars is the improved ability to see the abdominal cavity because vision is not obscured by adhesions. This allows for better assessment of location of remaining ports. Also, surgeons then have the appropriate working distance necessary to manipulate instruments. The laparoscope can be placed through the umbilical trocar after all trocars are placed under direct visualization.

 

OBESITY

One of the major technical problems encountered in obese patients is access to the abdominal cavity, which is especially difficult with the needle-insertion technique. Because of the thickness of the abdominal wall and the preperitoneal fat, accurate assessment of the location of the tip of the needle is difficult, making preperitoneal insufflation common. The umbilicus is the thinnest area of the abdominal wall, and needle insertion at this point is probably easiest. Once the needle is inserted, the saline drop test and confirmation of an initial low intra-abdominal pressure are

crucial in confirming proper intra-abdominal placement. If any concerns exist about proper positioning, the needle should be removed. Surgeons may need to attempt insertion numerous times before success is achieved. Occasionally an extra long Veress needle may be reqired.

Another alternative is the use of the open insertion technique with a Hasson trocar. Controversy exists over the advantages and disadvantages of this access technique compared with a closed technique in obese patients. Some investigators believe that a large skin incision is necessary for Hasson trocar insertion in obese patients, leading to perioperative leakage of gas and to increased rates of wound infection postoperatively. Other investigators believe that the open insertion technique is successful and, as surgeons gain experience, can be performed in a timely fashion with minimal morbidity.

Encouraging reports from the Cleveland clinic suggest that the use of optical trocars may reduce the unacceptable risk of vascular and bowel injury in this group of patients