INTRODUCTION — Wound complications are important causes of early and late postoperative morbidity following laparotomy. Surgical wounds in normal, healthy individuals heal through an orderly sequence of physiologic events that includes inflammation, epithelialization, fibroplasia, and maturation. Mechanical failure or failure of wound healing at the surgical site can lead to disruption of the closure leading to seroma, hematoma, wound dehiscence, or hernia. Other complications include surgical site infection and nerve injury. This topic will review prevention and treatment of complications of abdominal surgical incisions.
HEMATOMA AND SEROMA — Hematoma and seroma are collections of blood and serum, respectively. Hematomas are more common than seromas and usually result from failure of primary hemostasis or a bleeding diathesis (eg, anticoagulation). Hematomas and seromas can cause the incision to separate and predispose to wound infection since bacteria can gain access to deeper layers and multiply uninhibited in the stagnant fluid.
Clinical manifestations and diagnosis — Clinical manifestations usually appear a few days after surgery but can also be delayed. Collections of blood or serum in the wound may be asymptomatic or manifest as swelling, pain, and/or drainage. If the collection is infected, fever, erythema, wound induration, and leukocytosis are also likely. (See 'Surgical site infection' below and "Overview of the evaluation and management of surgical site infection".)
The diagnosis can usually be made by inspection and palpation of the wound. If the examination is in question, ultrasound or computed tomography (CT) can be used to confirm the diagnosis.
Treatment — Small hematomas and seromas can be managed expectantly, while large collections should be drained. For symptomatic hematomas, the wound is opened partially or completely under sterile conditions. If there is no evidence of infection, the wound can be closed immediately. For suspected seroma, aspiration under sterile conditions may be all that is required.
More commonly after exploration, the wound is packed until granulation tissue is present and then closed in a delayed fashion, or the wound is allowed to heal by secondary intention. Delayed closure significantly reduces healing time compared with healing by secondary intention [1,2]. (See "Basic principles of wound management", section on 'Wound closure' and "Basic principles of wound management", section on 'Wound packing'.)
Prevention — Meticulous hemostasis during surgery is essential. Procedures that are associated with a potential for collections of blood and serum in the subcutaneous tissues may benefit from prophylactic wound drainage, especially when large potential dead spaces are created (ie, repair of large ventral hernia, post-mastectomy). The prevention of fluid collection and subsequent infection is the primary aim. Obesity is a risk factor for local wound complications, and drain placement may reduce complications but is controversial . The use of drains in abdominal wound closure is discussed elsewhere. (See "Principles of abdominal wall closure", section on 'Drains'.)
SURGICAL SITE INFECTION — Surgical site infection (SSI), which can be superficial or deep, occurs in approximately 4 percent of clean wounds and 35 percent of grossly contaminated wounds. The Centers for Disease Control and Prevention definitions of and criteria for surgical site infection are shown in the figures (figure 1 and table 1). Patient-specific risk factors for surgical site infection include diabetes, obesity, immunosuppression, cardiovascular disease, smoking, cancer, previous surgery, malnutrition, and prior irradiation. Technical risk factors are listed in the table (table 2).
Clinical manifestations and diagnosis — The diagnosis of wound infection is clinical. Symptoms include localized erythema, induration, warmth, and pain at the incision site. Purulent wound drainage and separation of the wound may occur. Some patients will have systemic evidence of their infection such as fever and leukocytosis. (See "Fever in the surgical patient".)
Necrotizing fasciitis, perhaps the most serious wound infection, can be lethal and is a surgical emergency. It is characterized by a copious, dishwater-like drainage; dusky and friable subcutaneous tissue; and pale, devitalized fascia. (See "Necrotizing soft tissue infections".)
Treatment — Infected wounds are opened, explored, drained, irrigated, debrided, and dressed open. If fascial disruption is suspected, drainage should be performed in the operating room. Once the infection has cleared and granulation tissue is apparent, the wound can be closed secondarily. The need for antibiotic therapy is determined by the extent of the infection, presence of systemic manifestations, and comorbidities of the patient (eg, immunocompromise, diabetes, chronic steroids). (See 'Antibiotic therapy' below and "Overview of the evaluation and management of surgical site infection", section on 'Wound exploration and debridement'.)
Incision and drainage — A syringe filled with saline solution can be used to apply irrigation under pressure to remove loose dead tissue, exudate, and clots. Saline is favored because it is an isotonic solution and does not interfere with the normal healing process; however, tap water has also been used for wound care in the home or ambulatory setting with good results . (See "Basic principles of wound management", section on 'Irrigation'.)
Mechanical debridement is performed with forceps and scalpel or scissors. All foreign bodies and devitalized tissue are excised because they can delay healing and promote infection. Debridement is discontinued once necrotic tissue has been removed and granulation tissue is present. Enzymatic agents are also available and are useful when manual debridement is not possible . (See "Basic principles of wound management", section on 'Wound debridement'.)
Deep wounds may require packing. Gauze is moistened with normal saline and placed into the wound and covered with dry layers of gauze . When the gauze is removed (preferably before it dries out), necrotic tissue is removed with it, which provides a form of debridement. However, once debridement is no longer necessary, the packing material should be changed from gauze to one that is less traumatic to the developing granulation tissue and new epithelial cells. Dressing changes may be required up to three times daily and are continued until the wound surface is mostly covered by granulation tissue. (See "Basic principles of wound management", section on 'Wound packing'.)
Wound dressings — Dressings that maintain moisture and warmth facilitate healing . Retention of moisture is important because wound fluids contain tissue growth factors that facilitate reepithelialization and promote autolytic debridement. Once necrotic tissue has been removed and the wound is granulating, these dressings can be changed once a day or every other day in order to avoid disturbing the healing process.
The ideal dressing for healing wounds by secondary intention should absorb exudate without leakage, be impermeable to water and bacteria, lack particulate contaminants that could be left in the wound upon removal, and not be traumatic to granulation tissue . Many choices are available without good data to recommend one over another (table 3) . (See "Basic principles of wound management", section on 'Wound dressings'.)
Negative pressure wound therapy (also called vacuum-assisted wound closure) can be used for wounds that have a clean, granulating base. The negative pressure reduces excess fluid accumulation and, with time, the size of large complex wounds. It also helps protect the patient's skin from irritation from frequent dressing changes since it is only changed every three to five days.
When treating a surgical wound that is moderately large or is expected to take more than a week to heal, negative pressure wound therapy is preferred to conventional dressing due to decreased pain and skin trauma to the patient and convenience. In a trial of 539 patients with subcutaneous abdominal wounds, negative pressure wound therapy, when compared with conventional wound treatment, resulted in higher wound healing rate within 42 days (36 versus 22 percent) and shorter healing time (36 versus 39 days) but a greater number of wound-related adverse events in treatment-compliant patients (relative risk 1.51, 95% CI 0.99-2.35) .
The techniques for placement and care of wounds with these devices are discussed elsewhere. (See "Negative pressure wound therapy".)
Antibiotic therapy — Wound infections associated with cellulitis alone (ie, no fluctuance) can be treated with a course of antibiotics without open drainage. Superficial incisional SSIs that have been opened can usually be managed without antibiotics. Topical agents (eg, povidone-iodine, sodium hypochlorite, hydrogen peroxide) do not offer any advantage over drainage and debridement and should be avoided since they may be toxic to fibroblasts and, as a result, impede wound healing.
For more severe infections, as evidenced by extension into adjacent tissue or systemic signs, empiric treatment is started using broad-spectrum antibiotics with coverage of gram-positive cocci from the skin as well as the expected flora at the site of operation. Definitive antimicrobial treatment is guided by the clinical response of the patient and, when available, results of gram stain, wound culture, and sensitivity. However, wound swab cultures often reveal polymicrobial growth, making it difficult to distinguish colonization from true infection. (See "Cellulitis and skin abscess in adults: Treatment".)
Delayed closure — Traditionally, wounds that have been opened due to infection are left to heal by secondary intention. However, delayed closure is safe and effective, with only a 5 percent incidence of reexploration for reinfection. Closure significantly shortens the healing time .
Prevention — Surgeons can reduce rates of surgical site infection using preventive measures that include avoiding surgery in patients with active infection, antibiotic prophylaxis, proper skin preparation, and maintenance of sterile conditions . These are discussed elsewhere; surgical techniques to prevent surgical site infection are briefly reviewed below. (See "Overview of control measures for prevention of surgical site infection in adults" and "Antimicrobial prophylaxis for prevention of surgical site infection in adults".)
Surgical technique — Surgical technique that avoids excessive tissue handling and ischemia while providing adequate hemostasis is the first step toward preventing infection. Other surgical techniques that may impact infection rates include:
●Use of electrocautery – Controversy persists regarding the choice of scalpel or electrocautery for incision of the subcutaneous tissues. Multiple strokes in the incision, whether by scalpel or electrosurgery, result in greater tissue damage. Excessive dissection of the subcutaneous tissues also increases the dead space, which can predispose to fluid collection and subsequent infection. We prefer to use a scalpel for the skin incision and electrosurgery for the subcutaneous tissue and fascia.
Electrosurgery is associated with varying degrees of thermal damage to tissue. A concern is that the resulting necrotic tissue will become a focus of infection and potentially weaken the repair. However, when a nonmodulated (cutting) current is used with a peak voltage of 200 volts, tissue is vaporized with minimal thermal spread beyond the point of incision, thus producing tissue damage no worse than that resulting from a sharp scalpel. The use of electrosurgery rather than a scalpel for both incision of the skin and underlying tissues is also accepted. This practice is supported by a systematic review and meta-analysis comparing electrosurgery versus scalpel for incision of skin and subcutaneous tissue that showed no differences in the incidence of wound infection . Electrosurgery may be associated with less pain. (See "Incisions for open abdominal surgery", section on 'Skin incision'.)
●Closure of subcutaneous tissue – Closure of the subcutaneous tissues following abdominal fascial closure has been studied as it relates to the incidence of wound infection in certain circumstances. In the general surgical literature, there is no evidence to suggest an increased incidence of infectious or noninfectious wound complications when the subcutaneous tissues are not sutured . However, in the obstetric literature, there is evidence that closure of Camper's fascia at the time of cesarean delivery reduces the incidence of superficial wound disruption, particularly in patients with at least 2 cm of subcutaneous fat [13,14]. A trial of abdominal hysterectomy patients showed similar results . Closure of the subcutaneous tissue at the time of hysterectomy in women with greater than 2.5 centimeters of subcutaneous fat resulted in a lower incidence of wound disruption. In these studies, superficial disruption often was associated with seroma, hematoma, or infection. (See "Principles of abdominal wall closure", section on 'Subcutaneous'.)
●Skin closure – Staples are less likely to obscure wound drainage and impending separation than subcuticular sutures. If part of the wound becomes infected, only a few select staples need be removed without opening the entire skin incision as generally occurs once a subcuticular suture is cut. (See "Principles of abdominal wall closure", section on 'Skin'.)
However, obstetricians prefer subcuticular sutures rather than staples for closure of Pfannenstiel incisions because of a lower infection rate .
●Delayed closure – Delayed closure and healing by secondary intention are equally effective alternatives in cases of infection or wound contamination . A trial that compared delayed closure to healing by secondary intention in patients with superficial wound dehiscence showed that delayed closure resulted in faster healing time and fewer postoperative visits .
Delayed closure may be accomplished under local anesthesia using sutures or a nonocclusive adhesive bandage. Optimally, closure should be performed after granulation tissue has started to form, normally in four to five days, and before wound contraction has begun. Closure beyond 10 postoperative days is associated with greater risk of wound infection, making secondary intention preferable in this circumstance .
●Hypothermia – Body temperature and tissue oxygenation may significantly impact wound healing and the risk of surgical site infections. Perioperative hypothermia by one degree Celsius triggers thermoregulatory vasoconstriction, which decreases tissue oxygen tension and directly impairs antibody- and cell-mediated immune defenses. Reduced availability of tissue oxygen interferes with collagen deposition, which decreases tensile wound strength. Suppression of mitogen-induced activation of lymphocytes and reduced production of cytokines, IL-1beta and IL-2, may be responsible for the increased risk of SSIs.
Clinically, core hypothermia triples the incidence of SSIs following colon resection and extends the duration of hospitalization by 20 percent . In the absence of a specific indication for therapeutic hypothermia, normothermia should be maintained in the perioperative period.
●Adjunctive therapies – While delivery of adequate oxygen through the microcirculation is vital for optimal healing and resistance to infection, the benefit of supplemental oxygen in the perioperative period has not been substantiated. Surgical patients should continue to receive oxygen supplementation with cardiorespiratory physiology as the principal determinant. (See "Mechanical ventilation during anesthesia in adults", section on 'Oxygen supplementation and surgical site infection'.)
Preoperative and postoperative hyperbaric oxygen therapy may be beneficial in situations where local injury, poor microcirculation, or infection, particularly associated with anaerobic organisms, compromises tissue healing. However, definitive benefit of this therapy is yet to be established, and the indication for hyperbaric oxygen therapy must be individualized [20,21]. (See "Basic principles of wound management", section on 'Hyperbaric oxygen therapy'.)
FASCIAL DEHISCENCE — Fascial disruption is due to abdominal wall tension overcoming tissue or suture strength, or knot security. It can occur early or late in the postoperative period and involve a portion of the incision (ie, partial dehiscence) or the entire incision (ie, complete fascial dehiscence). The incidence of fascial disruption ranges from 0.4 to 3.5 percent depending upon the type of surgery performed [22-25]. Despite improved perioperative care and stronger suture materials, the incidence and morbidity of fascial dehiscence are largely unchanged.
With early fascial dehiscence, the skin closure may be intact depending upon the method of closure (ie, staples, sutures); the patient, nevertheless, is at risk for evisceration. Thus, early postoperative fascial dehiscence is a surgical emergency. The late complication of fascial disruption is incisional hernia. Incisional hernia is discussed in detail elsewhere. (See "Overview of abdominal wall hernias in adults", section on 'Ventral incisional hernia'.)
Patient risk factors — Independent risk factors for fascial disruption in one risk model included age, male sex, chronic pulmonary disease, ascites, anemia, emergency surgery, postoperative coughing, wound infection, and the type of surgery . Other factors include malignancy, obesity, hypoalbuminemia (poor nutrition), sepsis, and chronic glucocorticoid therapy (table 4) . Diabetes mellitus alone was not a risk factor for fascial dehiscence in these observational studies.
Technical factors — Fascial dehiscence may also be related to technique. (See "Incisions for open abdominal surgery".)
Incisional factors — Tension on an incision is proportional to its length . Herniation is more common when the incision length exceeds 18 cm . It was thought that longitudinal incisions were at greater risk of dehiscence than transverse incisions. However, it is difficult to make legitimate comparisons since longitudinal incisions are more likely to be performed in cases of hemorrhage, trauma, sepsis, multiorgan disease, previous surgery, previous radiation therapy, and malignancy. Randomized trials comparing paramedian, transverse, and midline incisions have reported no significant differences in the frequency of dehiscence or herniation [29-31].
Suture — The main causes of wound separation are failure of suture to remain anchored in the fascia, suture breakage, knot failure, and excessive stitch interval, which allows protrusion of viscera . In up to 95 percent of abdominal wound dehiscences, the sutures and knots are intact, but the suture has pulled through the fascia [33-35]. This is usually the result of fascial necrosis from sutures being placed too close to the edge or under too much tension. Sutures should be approximately 1 cm from the wound edge and approximately 1 cm from the adjacent suture to ensure that the tissue is strong enough to hold the suture. For continuous closure, the total length of the suture should be approximately four times the length of the incision . (See "Principles of abdominal wall closure", section on 'Technique'.)
To minimize the risk of incisional hernia, elective midline abdominal closure (first operation or reoperation) should be performed with continuous, slowly absorbable sutures . (See "Principles of abdominal wall closure", section on 'Midline'.)
Clinical manifestations and diagnosis — Signs and symptoms of a complete dehiscence include profuse serosanguinous drainage, often preceded by a popping sensation, and an incisional bulge exacerbated by Valsalva maneuvers. Most dehiscences occur 4 to 14 days after surgery, with a mean of 8 days. The diagnosis can be made based upon clinical grounds in the majority of cases.
The absence of a healing ridge in a laparotomy incision by postoperative day 5 can be a sign of impaired healing and impending disruption [22,38]. Imaging studies, such as ultrasonography and computed tomography, are used when the diagnosis is unclear.
Treatment — When fascial disruption is suspected, wound exploration should be performed in the operating room. Complete fascial dehiscence is associated with a mortality rate of 10 percent and is a surgical emergency.
At the bedside, a moist dressing is placed over the wound and a binder can be placed around the patient's abdomen to prevent overt evisceration on the way to the operating room. A binder should not be used in cases of complete dehiscence and evisceration due to the potential for bowel injury.
Once the wound is opened, the edges are thoroughly debrided. A mass closure with continuous, slowly absorbable suture should be performed . Depending upon the circumstance, the skin may or may not be left open. (See "Principles of abdominal wall closure", section on 'Midline'.)
Internal or external retention sutures are occasionally used to reapproximate the fascial edges after a postoperative fascial dehiscence . However, the use of retention sutures has declined over the years because it causes increased pain and local skin complications without significantly reducing the risk of fascial disruption or incisional hernia .
Prevention — The method of fascial closure is a critical aspect of incisional closure as this provides the majority of wound strength during healing. Two meta-analyses related to abdominal fascial closure suggest that an optimal technique for closure of abdominal surgical wounds includes [37,41]:
●Use of a simple running technique
●Use of #1 or #2 delayed absorbable suture
●Use of mass closure to incorporate all layers of the abdominal wall (except skin)
●Taking wide tissue bites (approximately 1 cm)
●Use of a short stitch interval (approximately 1 cm)
●Use of a suture length to wound length ratio of 4 to 1
●Use of nonstrangulating tension on the suture
Continuous mass closure or interrupted Smead-Jones closure (vertical mattress) with permanent or delayed absorbable suture are both safe and effective. Most midline closures should be performed with continuous mass closure supported by several meta-analyses. (See "Principles of abdominal wall closure", section on 'Midline'.)
Lifting — Postoperatively, patients are commonly counseled to avoid heavy lifting following laparotomy to prevent wound dehiscence. This is based upon the concern that an increased intra-abdominal pressure can result in wound disruption, but there are few data regarding how much weight is safe to lift. Intra-abdominal pressure depends upon the amount of weight lifted and the position of the person relative to the object lifted [42,43]. As an example, in one study, intra-abdominal pressure was measured using a rectal pressure transducer for a range of activities . Many activities, such as lifting 8, 13, and 20 lbs from a counter; lifting 8 or 13 lbs from the floor; climbing stairs; walking briskly; or doing abdominal crunches did not increase intra-abdominal pressure more than standing up from a seated position.
Nevertheless, we suggest patients avoid heavy lifting (>13 pounds of weight from the floor) for four to six weeks following abdominal surgery to minimize stress on the healing fascia. If the patient cannot easily lift an object with one hand, help should be sought.
NERVE INJURY — Nerve injury can lead to unexpected and distressing symptoms following an otherwise successful operation. Pain, loss of sensation, and abdominal wall weakness are the most common symptoms. Three mechanisms of nerve injury occur: transection (from incision), entrapment (from fascia closure), and compression/stretching (from retraction of tissues or patient positioning). Local nerve injury leading to chronic incisional discomfort is well recognized, but not all chronic incisional pain is due solely to nerve injury.
Nerve injuries associated with pelvic surgery and hernia surgery are discussed in detail elsewhere. (See "Nerve injury associated with pelvic surgery", section on 'Prevention of nerve injury' and "Open surgical repair of inguinal and femoral hernia in adults", section on 'Minimizing post-herniorrhaphy neuralgia'.)
Obesity — Obesity complicates incision selection because exposure is compromised, operating may be difficult, and wound healing may be compromised. Obesity is associated with an increased incidence of wound infection, hematoma formation, incisional hernia, and medical complications.
Morbid obesity, defined as body mass index >40 kg/m2, often results in a large protruding panniculus, which presents an especially difficult technical problem. Topography of the abdominal wall is distorted, displacing the umbilicus caudally in a position that does not accurately estimate the sacral promontory.
Whether a transverse or longitudinal incision is superior in the obese patient remains a controversial issue. However, placing the incision in a deep transverse skin crease, which often contains macerated skin and a high concentration of microorganisms, may increase the risk of infection and should be avoided. Self-retaining retractors (figure 2A-B) aid exposure .
In obese patients without a significant panniculus, traditional midline or transverse incisions can be used and extended, as needed, around the umbilicus [45,46].
Alternatively, to facilitate lower abdominal incisions in patients with a large panniculus, a low midline (figure 3) or transverse (figure 4) incision can be made after pulling the panniculus cephalad .
Supraumbilical incisions can be made retracting the panniculus downward (figure 5).
Panniculectomy — Panniculectomy may alleviate problems of surgical exposure, reduce operating time, and reduce postoperative problems with wound healing. Panniculectomy facilitates surgery when adipose tissue is so thick that even the longest instruments cannot reach the site of dissection and when the abdomen hangs down over the symphysis and onto the thighs, thus increasing the risk of poor wound healing. Panniculectomy is typically performed in association with the planned abdominal operation typically by a plastic surgeon, and on occasion by a general surgeon well versed with the procedure. The details of the technique are beyond the scope of this topic.
Radiation — Radiation effects can be divided into acute and chronic reactions. The acute reaction consists of rapid cessation of mitotic activity, followed by cellular swelling. Edema develops in the walls of small vessels, and connective tissue becomes edematous and congested because of dilated and engorged lymphatic channels and small vessels. Radiation inhibits differentiation of fibroblast from mesenchymal cells and proliferation of endothelial cells into vascular buds. If the injury is lethal, cellular dissolution and focal necrosis may be seen.
Chronic radiation injury is caused by progressive vascular injury, a small vessel endarteritis. Endothelial swelling and proliferation narrows the vessel lumen, which restricts blood flow and may cause thrombosis. Similar effects occur in lymphatic channels. The supply of oxygen and nutrients is reduced to critical concentrations. The humoral and cellular immune defense systems function inefficiently. Proliferation of fibrous tissue causes the skin of the abdominal wall to lose suppleness, harden, and become atrophic, manifested as a shiny appearance with loss of the skin appendages. The skin becomes pigmented, and telangiectasias develop . These changes, more common with orthovoltage radiation techniques than newer linear accelerators, are progressive over several years and never heal or resolve.
Patients undergoing radiation therapy have a window of vulnerability to toxic effects. If 2.5 Gy is administered 24 hours before surgery, there is little impact on wound repair. However, the same dose administered 36 hours after surgery will maximally retard neovascularization and normal tissue contraction.
Radiation effects are more harmful to an open wound than a closed wound; this effect diminishes five to seven days after the incision is made. A wound that has completely epithelialized and has no fluid or blood collection can be irradiated one week postoperatively without negative effects. Radiation has minimal effects on a mature wound; however, radiotherapy of an infected wound will result in formation of a chronic radiation ulcer. If bowel adhesions limit peristalsis, significant bowel injury may occur.
Cancer has little direct effect on wound healing or fascial disruption, but associated poor nutrition resulting from limited intake or cancer-related compromised bowel function may slow the healing process. In addition, incisions placed in a previous irradiation field may heal poorly due to radiation-induced endarteritis. Cancer patients are more likely to have wound contamination from an opened viscus or intra-abdominal abscess, and postoperative ileus or collection of ascites may stress the fresh wound.
Prevention — Incision placement and timing may be modified to reduce the risk of wound complications. If possible, incisions should be placed outside the intended radiation field. Alternatively, surgery performed four to six weeks after radiotherapy will display relatively normal healing because postoperative inflammation is subsiding and blood supply is still adequate. Over time, the impact of diminished microcirculation from radiation presents an obstacle to wound healing, and the risk of surgery rises logarithmically as the dose of irradiation increases.
Irradiated tissue may not have sufficient blood supply to withstand multiple incisions without necrosis. Therefore, skin incisions must never be crossed or made parallel in a field of irradiated tissue because of significantly increased risk of skin necrosis, poor healing, and infection. Pain in irradiated wounds may be from ischemia. Because of susceptibility to any type of injury, any insult may trigger a cycle of necrosis and infection.
Patients who have undergone preoperative radiation also have delayed healing, reduced tensile strength, and increased risk of infection. The increased risk of dehiscence warrants a closure technique utilizing permanent suture materials, which have been shown to reduce wound complications . Delayed absorbable synthetic suture also may be appropriate for some patients . (See "Principles of abdominal wall closure".)
SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Abdominal incisions and closure".)
SUMMARY AND RECOMMENDATIONS
●Surgical wounds in normal individuals heal through an orderly sequence of physiologic events. Mechanical failure or failure of wound healing at the surgical site can lead to disruption of the closure leading to wound complications. (See 'Introduction' above.)
●Hematoma and seroma are collections of blood and serum, respectively, and can cause the incision to separate, increasing the risk of wound infection. (See 'Hematoma and seroma' above.)
●Risk factors for surgical site infection include smoking, diabetes, malnutrition, cancer, obesity, immunosuppression, cardiovascular disease, prior incision, and irradiation at the surgical site. Meticulous surgical technique that avoids excessive tissue injury and ischemia while providing adequate hemostasis is important for preventing infection. (See 'Surgical site infection' above and "Overview of the evaluation and management of surgical site infection".)
●Infected wounds are opened, explored, drained, irrigated, debrided, and dressed open. If fascial disruption is suspected, drainage should be performed in the operating room. The severity of the infection determines the need for antibiotic therapy. Once the infection has cleared and granulation tissue is apparent, the wound can be closed secondarily or allowed to heal by secondary intention. (See 'Treatment' above and "Overview of the evaluation and management of surgical site infection", section on 'Wound exploration and debridement'.)
●Surgeons can modify rates of wound infection with preventive measures that include avoiding surgery in patients with active infection, antibiotic prophylaxis, proper skin preparation, and maintenance of sterile conditions intraoperatively. Proper surgical technique with gentle tissue handling and a secure closure that does not cause tissue ischemia are equally important. (See 'Surgical technique' above and "Overview of the evaluation and management of surgical site infection".)
●Fascial disruption is due to abdominal wall tension overcoming tissue or suture strength, or knot security. It can occur early or late in the postoperative period. With early fascial dehiscence, the skin closure may be intact depending upon the method of closure (ie, staples, sutures). The patient is at risk for evisceration, and early postoperative fascial dehiscence is a surgical emergency. The late complication of fascial disruption is incisional hernia, which can lead to bowel obstruction, ischemia, and even death. (See 'Fascial dehiscence' above.)
●Obesity complicates abdominal surgery and is associated with an increased incidence of wound infection, hematoma formation, and incisional hernia. Transverse incision, supraumbilical incision, or, occasionally, panniculectomy are techniques to manage the obese patient with a large pannus. (See 'Obesity' above.)
●Irradiated skin is also associated with an increased incidence of wound breakdown. Where possible, incisions should be placed outside the field of future or past radiation. Skin incisions should not be crossed or made parallel in a field of previously irradiated tissue due to a significantly increased risk of poor healing, infection, and, potentially, skin necrosis. (See 'Radiation' above.)