Expert Panel: Techniques and tools to prevent pelvic adhesions
Microsurgical techniques, laparotomy versus laparoscopy, use of adjunctive therapy—our panelists relate their views on these issues and discuss which options they would choose in 4 different scenarios.
- Alan DeCherney, MD, moderator, is professor, department of obstetrics and gynecology, and chief, division of reproductive endocrinology and infertility, David Geffen School of Medicine, University of California, Los Angeles.
William Hurd, MD, is professor and chair, department of obstetrics and gynecology, Wright State University School of Medicine, Dayton, Ohio.
Kelly Pagidas, MD, is reproductive endocrinologist and assistant professor of obstetrics and gynecology, Brown University, Providence, RI, and Tufts University, Boston, Mass.
Joseph S. Sanfilippo, MD, MBA, is professor, department of obstetrics, gynecology, and reproductive sciences, University of Pittsburgh, and vice chairman of reproductive sciences, Magee-Womens Hospital, Pittsburgh, Pa. He also serves on the OBG Management Board of Editors.
- Approximately 40% of people who undergo primary surgery develop adhesions and reformation occurs in 80% to 90% of cases.
- Microsurgical techniques such as gentle handling of tissues, careful hemostasis, and avoidance of heat may help reduce the incidence.
- Laparoscopy appears to be less likely to produce adhesions than laparotomy.
- Ob/Gyns should be aware of the potential for adhesion-related bowel obstruction and take steps to prevent it.
Are adhesions a pathologic response to injury or a normal aspect of healing? Can they be avoided, or are preventive efforts part of the problem? How useful are the different barriers in gynecologic surgery? What is the ideal adjuvant?
OBG Management convened a panel of experts to explore these and other questions.
Common problem, high recurrence rate
DECHERNEY: Adhesion formation is serious because it is associated with clinical entities such as infertility, pelvic pain, and bowel obstruction. We all agree that approximately 40% of people who undergo primary surgery develop adhesions and that 80% to 90% of patients who undergo lysis develop recurrent adhesions.
SANFILIPPO: One study several years ago explored adhesion formation.1 Unfortunately, no matter how meticulous the surgeon is, adhesions will form, even with microsurgical techniques and carefully ensured hemostasis.
HURD: The number of patients with significant adhesion formation after some gynecologic procedures has been reported to be greater than 90%.2
DECHERNEY: That higher incidence usually occurs after general surgery—and there’s a reason it is so high: General surgeons don’t use adjunctive therapy. They are critical of it. It is to our credit as gynecologic surgeons that we adopted adjunctive therapies about 15 years ago with the introduction of dextran 70 (Hyskon; Medisan Pharmaceuticals, Parsippany, NJ).
PAGIDAS: If anything, the pelvis seems to have even more of a predilection for adhesion formation than the abdomen, probably because of the close proximity of structures.
How and why adhesions form
DECHERNEY: What is the pathophysiology of adhesion formation? Let’s say you have 2 raw surface areas. What happens?
PAGIDAS: The increase in leukotrienes and prostaglandins and the decrease in plasminogen activity (which actually initiates the inflammation) appear to be significant.
HURD: Vessel permeability also increases, and inflammatory cells leak through the vessels and set up a matrix for adhesion formation.
DECHERNEY: So we have 2 raw surface areas with fibrin leaking out and forming bridges between them.
PAGIDAS: The key is that it takes 2 surfaces to form these bridges. As I mentioned, the greater proximity of pelvic structures—particularly around the tube and ovary—probably contributes to adhesion formation.
DECHERNEY: Macrophage activity also is important. The macrophage “migrates” along these fibrin bridges and lays down collagen over a period of time. Then the collagen becomes organized and, eventually, vascular.
Window of opportunity
SANFILIPPO: Adhesion formation probably occurs and is pretty well established within 5 to 7 days of the precipitating event—usually surgery. Once that process is under way, attempts to halt it yield diminishing returns. Unfortunately, we don’t know how to interfere with it in a positive way.
HURD: Under normal conditions, there seems to be a balance between fibrin deposition and fibrinolysis. In some tissues, however, these functions become imbalanced. This disparity may contribute more to adhesions than the actual laying down of fibrin—especially in tissue that is hypoxic.
DECHERNEY: Would you say that adhesion formation represents normal or abnormal healing?
HURD: It is one of the body’s normal protective mechanisms and an important part of healing. Without it, any abdominal injury would likely result in death.
SANFILIPPO: I don’t think it differs that much from processes that occur externally. For example, if you get cut deeply enough, you develop a scar. Is that scar part of the normal healing process? It is.
PAGIDAS: Right. It is a normal process of tissue remodeling. The question is: What allows it to go astray?
What surgical techniques help prevent adhesions?
DECHERNEY: Let’s review the aspects of surgical technique that are important for adhesion prevention.
PAGIDAS: I emphasize the value of microsurgical techniques, which help to minimize severe tissue handling. It also is important to keep surfaces moistened so they don’t desiccate.
SANFILIPPO: I agree with Dr. Pagidas about microsurgical techniques such as gentle tissue handling, careful hemostasis, and keeping tissues moist. If we follow these principles, we create an environment that minimizes the potential for adhesion formation.
HURD: The findings of many well-controlled animal studies have been surprising. For example, it is difficult to demonstrate that drying of tissue increases adhesions.3 Probably the greatest contributor to adhesions in these models was abrasion.4 One way that laparoscopic surgery decreases adhesions is by avoiding abrasion of the bowel mucosa, which occurs specifically with packing.
CASE 1 Minimizing adhesions following myomectomy
A 38-year-old mother of 2 undergoes myomectomy for menorrhagia.
SANFILIPPO: The initial question is: Can this case be managed laparoscopically? I do myomectomies laparoscopically whenever possible, although I do close the uterus with a minilaparotomy incision. The reason is my strong concern about reapproximating the myometrium, since wound dehiscence sometimes occurs at the site of myoma removal.
In this case, depending on the size of the myomas, I would do as much as possible laparoscopically and then reapproximate the myometrium. I would plan my incisions carefully, to maximize the number of myomas that can be removed. I would end with meticulous hemostasis and, assuming it is successful, use a barrier over the incision—in this case, Interceed.
HURD: Does the patient desire future childbearing? If so, I would avoid the laparoscopic approach because of the possibly increased risk of uterine rupture during pregnancy. If she isn’t planning pregnancy, there are more options.
The next question is: How many myomas are there, and where are they located? If they are intrauterine, a hysteroscopic approach would avoid extrauterine adhesions. If they are multiple and large, I am pretty much limited to laparotomy. If there is 1 or only a few myomas, a laparoscopic approach would be best.
I have not used Interceed. In laparoscopic cases, I worry that it would create more problems because, as you allow the carbon dioxide to decrease at the end of a case, oozing begins. Instead of a barrier, I would use limited hydroflotation.
SANFILIPPO: That’s a good point. At the end of the myomectomy, with the laparoscope in place, I decrease the insufflation, eliminating the tamponade effect. Then, assuming good hemostasis, I apply Interceed.
HURD: With open cases, I use Seprafilm, which takes practice because, as it gets wet, it sticks to anything, including gloves and instruments. But if you can put it down dry on the uterus, it sticks and stays in place. If oozing occurs, it seems to block or stop it.
PAGIDAS: I want to reiterate the importance of determining whether childbearing is an issue. In this case, the biggest concern is the risk of adhesions developing on our incision, so I would use a barrier. My preference would be Seprafilm or GoreTex. If we can limit adhesions at the incision site, then hopefully we can minimize bowel and tuboovarian adhesions, too.
In open cases, one thing we can do to minimize the risk of adhesions is to pack gently when needed. Also, we should avoid using packing to reposition the bowel.
Another factor frequently overlooked is the application of heat, which appears to be a very effective way to create adhesions. This probably isn’t an issue for laparoscopic cases, but when you use irrigation fluid in an open case, watch the temperature. If it feels hot to you, you need to worry about potential injury to the bowel surfaces.
PAGIDAS: That is critical. In abdominal cases you want to make sure irrigation fluid is warm, but not too warm, because heat increases the vascular permeability of vessels and leads to more macrophages, more prostaglandins, and more leukotrienes.
HURD: Another important element is the type of suture material used.
DECHERNEY: Overall, we need to minimize the use of sutures. For example, when I am operating laparoscopically on an ovarian cyst, I try to apply bipolar energy to the edges so that they will coapt without a stitch.
HURD: When it first became clear that suturing ovaries increased adhesion formation, we conducted a controlled trial of different kinds of sutures in animals. Not surprisingly, we found that the less reactive the suture, the fewer adhesions.5 Sutures that are absorbed more slowly, such as polydioxanone, seem to be less reactive.
Obviously, inert sutures like nylon are the least reactive, but they are permanent. It is assumed that animal-protein sutures such as chromic and plain gut are the most reactive, although I am not sure there are sufficient data to support that conclusion.
Multiple clinical studies have shown laparoscopy to be associated with a lower adhesion rate, although it isn’t clear why. It may be related to decreased suturing.
DECHERNEY: Bulk is important, too—that is, the number of throws in the suture. When Vicryl (polyglactin 910) became available, we conducted a study in mice using proportionately small Vicryl plaques to determine whether this would be good a barrier (A. DeCherney, MD, unpublished data). It caused a tremendous amount of adhesion because so much foreign matter was applied.
We also did a study using human-size titanium clips in rats (A. DeCherney, MD, unpublished data). Not surprisingly, there was a lot of adhesion formation.
FIGURE 1 Pelvic adhesions: How they develop, problems they cause
Adhesions occur when 2 or more raw surfaces are exposed to leaking fibrin, which forms a bridge between the surfaces. Macrophages “migrate” along these bridges, depositing collagen.
The pelvis has a greater predilection for adhesions than the abdomen because of the close proximity of structures.
Although adhesions represent one of the body’s protective mechanisms, they may also cause pain or interfere with fertility, bowel function, or other processes.
Laparoscopy versus laparotomy: More adhesions in open cases?
DECHERNEY: Based on all the techniques we have learned from microsurgery—with the exception of magnification—it appears that laparoscopic procedures are less likely to cause adhesions than laparotomy. Do you agree?
PAGIDAS: I think so. As Dr. Hurd noted, a main reason is the diminished tissue handling, because there is no packing.
DECHERNEY: Less bleeding occurs because surgeons are less aggressive laparoscopically than in laparotomy.
CASE 2 Preserving the integrity of the ovary
A 15-year-old undergoes removal of a dermoid cyst, which was shelled out laparoscopically.