This uncommon, severe wound infection is associated with high mortality rates. In obstetrics, necrotizing fasciitis may involve abdominal incisions, or it may complicate episiotomy or other perineal lacerations. As the name implies, tissue necrosis is significant. Of the risk factors for fasciitis summarized by Owen and Andrews (1994), three of these-diabetes, obesity, and hypertension-are relatively common in gravidas. Like pelvic these wound complications usually are polymicrobial and are caused by organisms that make up the normal vaginal lora. In some cases, however, infection is caused by a single virulent bacterial species such as group A O-hemolytic streptococcus (Anderson, 2014; Rimawi, 2012). Occasionally, necrotizing infections are caused by rarely encountered pathogens (Chong, 2016; Swartz, 2004).
Goepfert and coworkers (1997) reviewed their experiences with necrotizing fasciitis. Nine cases complicated more than 5000 cesarean deliveries, a frequency of 1.8 per 1000. In two women, the infection was fatal. In another report, Schorge and colleagues (1998) described ive women with fasciitis following cesarean delivery. None of these women had predisposing risk factors, and none died.
FIGURE 37-2 Necrotizing fasciitis involving the abdominal wall and Pfannenstiel incision. The skin rapidly became dusky and gangrenous, and pus is seen exuding from the left angle of the incision. Extensive debridement and supportive therapy were lifesaving.
Infection may involve skin, supericial and deep subcu taneous tissues, and any of the abdominopelvic fascial layers (Fig. 37-2). In some cases, muscle is also involved-myoosciitis.
Although some virulent infections-for example, those caused tum, most of these necrotizing infections do not cause symp toms until 3 to 5 days after delivery. Clinical findings vary, and it is frequently diicult to diferentiate more innocuous superi cial wound infections from an ominous deep fascial one. A high index of suspicion, with surgical exploration if the diagnosis is uncertain, may be lifesaving (Goh, 2014). We aggressively pursue early exploration. Certainly, if myofasciitis progresses, the woman may become ill from septicemia (Chap. 47, p. 921).
Early diagnosis, surgical debridement, antimicrobials, and intensive care are paramount to successfully treat necrotizing soft-tissue infections (Gallup, 2002; Goh, 2014). Surgery includes extensive debridement of all infected tissue, leaving wide margins of healthy bleeding tissue. This may include extensive abdominal or vulvar debridement with unrooing and excision of abdominal, thigh, or buttock fascia. Death is virtually universal without surgical treatment, and rates approach 25 percent even if extensive debridement is performed. With extensive resection, synthetic mesh may ultimately be required later to close the fascial incision (Gallup, 2002; McNeeley, 1998).
An ovarian abscess rarely develops in the puerperium. These are presumably caused by bacterial invasion through a rent in the ovarian capsule (Wetchler, 1985). The abscess is usually unilateral, and women typically present 1 to 2 weeks after delivery. Rupture is common, and peritonitis may be severe.
Peritonitis is infrequent following cesarean delivery. It almost invariably is preceded by metritis, especially cases with uterine incisional necrosis and dehiscence. However, it may stem from a ruptured adnexal abscess or an inadvertent intraoperative bowel injury.