Incision decisions: which ones for which procedures?
Incision selection plays an important role in gynecologic surgery, especially with regard to adequate pelvic access and preservation of abdominal wall function. Here, a guideline to the advantages and disadvantages of commonly used longitudinal and transverse incisions and the procedures for which they are best suited.
A midline incision allows the quickest entry, which is especially important for an unstable or seriously ill patient. Exposure is excellent, as all areas of the abdomen and retroperitoneum can be accessed with minimal risk of significant vascular or nerve injury. This is because only terminal branches of the abdominal wall blood vessels and nerves are located at the linea alba. In addition, because deep tissue planes are not opened, this incision may be ideal for patients who are anticoagulated, have enlarged epigastric vessels that are more susceptible to injury, or have an intraabdominal infection.
Transverse incisions help reduce the rate of wound dehiscence.
Disadvantages. Two potential problems are the higher rate of hernia formation and wound dehiscence, which may be due to constant lateral tension, compared with transverse incisions. In addition, coughing, retching, and straining may exacerbate the lateral tension. Proper suture selection can reduce the incidence of complications. As previously mentioned, the reality of these disadvantages is subject to debate; further studies are needed to determine the true risk.
From a cosmetic standpoint, the midline scar often is prominent because the incision transects Langer’s lines. Hence, it cannot be concealed by lingerie or swimwear.
FIGURE 1 Midline incision
After incising the linea alba and separating the muscles in the midline, open the peritoneum at the cephalad pole of the incision.
FIGURE 2 Midline incision
Expand this cut slightly off midline to avoid the urachus yet adequately expose the peritoneal cavity.
ParamedianTechnique. Place this incision 2 to 5 cm to the left or right of the midline, depending on the indication for surgery. After dissecting the skin and subcutaneous layers, incise the anterior rectus sheath vertically over the rectus abdominis muscle (Figure 3) and dissect it from the medial muscle edge. Retract the muscle laterally to expose the posterior rectus sheath and then incise the sheath and the peritoneum vertically to expose the peritoneal cavity (Figure 4). Alternatively, a more lateral paramedian incision can be placed over the rectus abdominis muscle. In this case, however, the rectus muscle should be separated vertically, instead of retracted laterally, to expose the posterior rectus sheath.
Rationale. Paramedian incisions provide excellent exposure of the pelvis, excluding the upper abdomen. Therefore, consider this technique when the procedure will be confined to the ipsilateral pelvis, e.g., rightor left-side lymph node biopsies and exposure of the sigmoid colon on the left. Also, a paramedian incision at the level of the umbilicus can be used for a cesarean delivery or a hysterectomy.
This incision is the best choice when performing pelvic surgery on morbidly obese patients. By placing the incision low on the abdomen, the large panniculus can be retracted over the mons pubis and thighs, providing excellent exposure of the pelvis.
Disadvantages. Some researchers have reported that muscle-splitting lateral paramedian incisions have a lower incidence of incisional hernias compared with midline incisions.7,9 However, they take longer to perform and restrict access to the contralateral pelvis. In addition, the risk of vascular injury and hematomas is increased, especially in the lower pole where branches of the epigastric arteries penetrate the muscle.
With regard to nerve injury, terminal nerves are cut, resulting in paralysis of the inner portion of the rectus abdominis muscle. This paralysis can be permanent, as the muscle medial to the vertical separation is involved. However, if only the medial third of the muscle is denervated, the paralysis rarely limits function.
FIGURE 3 Paramedian incision
Place the incision 2 to 5 cm to the left or right of the midline. Incise the anterior rectus sheath vertically over the rectus abdominis muscle.
FIGURE 4 Paramedian incision
Retract the muscle laterally to expose the posterior sheath; then incise the sheath and the peritoneum vertically to expose the pelvic cavity.
Transverse incisions
Transverse incisions such as Pfannenstiel’s (muscle separating), Cherney’s (tendon detaching), and Maylard’s (muscle cutting) were developed to reduce the incidence of incisional hernias and wound dehiscence. Their success lies in the fact that they cause less tension on the opposing wound edges because the incisions follow Langer’s lines, unlike longitudinal incisions. Their placement also allows for a better cosmetic outcome. Because they can be placed in the pubic hairline or in a natural skin crease, they are easily concealed by lingerie or swimwear. However, the incision should not be placed in a deep skin fold of a large panniculus where maceration of the skin can increase the risk of infection.
The main disadvantages of transverse incisions are limited exposure of the upper abdomen and limited extensibility. Further, because more tissue planes are opened and more vessels are encountered, these incisions increase the risk of hematomas and infection.
