20. Anchoring Laparoscopic Ports
John I. Lew, M.D.
Richard L. Whelan, M.D.
A. Introduction
The majority of laparoscopic ports are not threaded and are of uniform diam- eter. Unanchored, they are held in place by the abdominal wall, which surrounds or grips the port and provides resistance to outward forces applied to the port.
These ports tend to stay in place for short procedures that are carried out in one abdominal quadrant. However, during lengthy procedures that require working in several quadrants, the abdominal wall’s hold on the port may weaken and the port may be dislodged altogether, usually at the time of instrument removal. How is the abdominal wall’s grip on the port weakened? During any laparoscopic pro- cedure, varying amounts of torque are applied to each port to accomplish the task at hand. Depending on the degree and direction of the torque and the number of times the port is torqued, the port wound at the peritoneal level may enlarge.
The fascial wound may also be stretched and enlarged. Each time an instrument is withdrawn from a port, an outward force is applied to the port. When the abdominal wall’s grip on the port is sufficiently weak, the port is likely to dis- lodge. If the port inadvertently comes out of the abdomen, the procedure is dis- rupted and the pneumoperitoneum is lost. Further, replacing the port back into the abdomen can be difficult and may further enlarge the port wound, which will increase the chances of the port being dislodged again. In the setting of cancer, in theory, the rapid desufflation that occurs when a port is dislodged may serve to transport tumor-laden fluid droplets to the abdominal wound, which may put the patient at risk for a port wound tumor recurrence.
Anchoring ports to the abdominal wall, therefore, is advised for advanced procedures, especially those that require working in multiple quadrants. Well- secured ports will facilitate the timely completion of the case at hand. There are numerous methods of anchoring laparoscopic ports. Some involve modification of the port itself (addition of spiral threads) or of the method of port placement (i.e., bladed trocar versus dilating method) while other methods require the use of a separate device, usually cone shaped, through which the port is placed before insertion. Last, skin sutures can be used to create a tether that will prevent dis- lodgement. What follows is a brief explanation of these methods.
B. Port Anchoring Methods
1. Hassan-type devices: Cone-shaped obturator through which the port is passed before port placement. The original Hassan device was not threaded although threaded versions have since been developed. The original Hassan devices were reusable; there are now several disposable versions. The Hassan is used when the first port is placed via open cutdown. These wounds are usually a bit larger than the port to be placed; the cone-shaped Hassan essentially plugs the wound and prevents loss of gas around the port. The Hassan device is held in place by a fascial suture(s) that is placed at the time of the cutdown and sub- sequently pulled tight and wrapped around two flanges that extend out from the most external surface of the device.
2. Several companies make threaded disposable cone-shaped anchoring devices that are designed for use with ports placed via bladed trocars. The device grips the port tightly once the port has been passed through it. Once the port has been successfully inserted into the abdomen, the trocar is removed and the port is advanced until the innermost edge of the threaded port grip engages the wound edge. Next, the port and the anchor are together screwed into the abdominal wall until at least the first thread of the anchoring device can be seen inside the abdomen via the laparoscope. To loosen the grip of the device on the port, either to push the port further into the abdomen or to withdraw it, the surgeon must pinch together two spring-loaded plastic flanges that extend from the external- most part of the device. When pinched together, it is possible to slide the port within the sheath. Once the desired position has been obtained, the flanges are released, after which they return to their original position and the port is once again firmly held within the anchor.
3. Skin suture tether (alone): A tether can be created with a skin suture that will prevent the port from coming out beyond a certain point. First, the suture is placed through the skin and then tied down loosely just above the skin level. If the port fits snugly in the skin wound then this suture is placed adjacent to the port site. If the port skin incision is too large, the suture can be placed so as to partially close the port wound when tied down; this will serve to limit port slippage and to prevent or minimize the leakage of gas around the port. After the skin suture is placed and tied, several “air knots” are thrown such that a tether of the appropriate length is created. After additional knots are placed at that level, one end of the suture is wrapped around the insufflation arm that extends outward from the port and then is either tied or clamped to the other end of the suture. Ideally, the tether should be long enough so as to permit the port to be withdrawn to within a centimeter or so of the parietal peritoneum.
The tether will not prevent the port from moving further into the abdomen. This type of tether should prevent port dislodgement but it does not secure the port in a single position; the port can freely move back and forth for a certain distance.
4. Skin suture in conjunction with other port-anchoring device: The addition of a skin suture tether when using other anchoring systems ensures that the port will not become dislodged should the primary anchor fail. Some sur- geons believe that this precaution is warranted for cancer cases and in patients with thin abdominal walls and poor tissue integrity. A skin suture is placed close
to the port base and tied loosely at the skin level. One end of the suture is next wrapped several times around the insufflation arm and then pulled down toward the abdominal surface. The other end of the suture is pulled upward, after which the two strands are clamped together. Should the primary anchor fail, this suture will prevent the port from coming out. To reposition the port further in or out of the abdomen, the suture tether must be first released. When the desired posi- tion is attained, the suture tether is again wrapped around the insufflation arm and secured with a clamp as described above.
5. Full-thickness abdominal wall tether: This type of suture is utilized when trying to limit the expansion of the abdominal wall in the setting of sub- cutaneous emphysema, usually during a lengthy case. This must be done in con- junction with another anchoring device (for example, a threaded port or a threaded port grip). A large-diameter (#1 or #2) monofilament suture is passed into the abdominal cavity under direct visualization via a retention suture-type needle that has been straightened. Once in the abdomen, the needle is grasped with a laparoscopic instrument and then pulled fully into the abdomen. Next, the needle is carefully turned around and then passed back out of the abdomen close to the port in question. One end of the suture is then wrapped several times around the insufflation arm of the port and then pulled down toward the abdom- inal surface while the other end is pulled toward the ceiling. The two strands are then clamped together. The primary anchor prevents the port from sliding into the abdomen. The transabdominal wall suture compresses the abdominal wall.
This type of suture will also prevent port dislodgement, although it is not pri- marily used for this purpose.
6. The self-anchoring reusable Endoscopic Threaded Imaging Port (Endotip) was developed to prevent the injuries that bladed trocars may incur.
The Endotip port uses the principle of Archimedes to lift the abdominal wall tissues along an inclined spiral on the external surface of the port cannula after engaging the most superficial layer with a blunt notched tip. This trocar-less device is literally “screwed” into the abdomen; the blunt tip and the rounded edges of the spiral threads deflect rather than lacerate the vessels and surround- ing tissues within the abdominal wall. The external threads also serve to hold the port in place under most circumstances, even during lengthy procedures.
Some surgeons use a skin suture anchor, described above, in conjunction with the ENDOTIP port as insurance against the rare port dislodgement event that may otherwise occur. The port position can be altered by screwing the port either inward or outward. The laparoscope can be placed inside the Endotip port before screwing in the initial port after the abdomen has been insufflated via a Veress needle. The scope in the port permits the surgeon to observe the progress of the port as it is advanced into and through the abdominal wall. Secondary ports are inserted under direct laparoscopic vision using the primary port. These reusable cannulas have also been found to be equally safe and effective for use in the bariatric population. At the end of the procedure, the secondary ports are removed under direct laparoscopic vision by rotating them in a counterclock- wise direction. For the remaining camera port, the laparoscope is retracted 2 cm into the port cannula and locked into position. The laparoscope is held perpen- dicular to the patient’s abdomen while the port cannula is rotated counterclock- wise with the surgeon’s dominant hand. This permits visualization of the port wound as the port is removed.
7. VersaStep-type port: This bladeless trocar system makes use of an expandable sheath that is passed through the abdominal wall over a Veress-type needle after the abdomen has been insufflated. The synthetic sheath has diamond-shaped skeletal elements embedded in it that serve to neutralize and convert axial force to a purely radial vector. Once the sheath is in position, the needle is removed, after which a blunt obturator, which carries the port, is inserted into the expandable sheath. As the cone-shaped blunt obturator is pushed into the abdomen, the sheath’s position is secured with the surgeon’s nondomi- nant hand. The wound is dilated by the obturator such that it will accept the port.
The port and obturator must be passed far enough into the abdomen such that the port tip extends beyond the inner edge of the expandable sheath. Once in position, the obturator is removed. This device is self-anchoring, and deflects rather than lacerates abdominal wall vessels and structures. When the port and the sheath are removed at the end of the case, a relatively small wound remains because the stretched but uncut abdominal wall tissues return to their original position.
C. Discussion
It is recommended that some type of port anchor be used for advanced laparoscopic cases. Each of the methods described above should suffice; how- ever, each has its benefits and drawbacks. There has been a general trend away from bladed trocars in recent years to avoid sharp trocar-related injuries and to minimize the abdominal wall trauma. Port systems that make use of threaded trocar-less ports as well as those that utilize blunt dilatation are more attractive.
After removal of such devices, the remaining defects are reported to be one-half the size of wounds left behind by conventional trocars and therefore are not rou- tinely closed. Although there are studies reporting no cases of port site hernia formation after use of such devices, closure of all fascial defects greater than 10 mm is recommended. Although most hernias are associated with 10-mm ports or larger, there have been many reports of port site hernias occurring through 5-mm ports as well. The reported incidence of port site hernias in the general population after minimal access surgery is approximately 0.2%–3%; however, the true incidence may be actually higher.
Regardless of the anchoring method used, given a long enough case or an abdominal wall with poor integrity, the anchor may fail. In such cases, the surgeon should not hesitate to utilize a suture tether in conjunction with another primary anchor.
D. Selected References
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Plaus WJ. Laparoscopic trocar site hernias. J Laparoendosc Surg 1993;3(6):567–570.
Reardon PR, Preciado A, Scarborough T, et al. Hernia at 5-mm laparoscopic port site pre- senting as early postoperative small bowel obstruction. J Laparoendosc Adv Surg Tech A 1999;9(6):523–525.
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Ternamian AM, Deitel M. Endoscopic threaded imaging port (ENDOTIP) for laparosopy:
experience with different body weights. Obes Surg 1999;9(1):44–7.
