Ventral and Incisional Hernias

Ventral Hernias

1. Umbilical Hernias
1. Etiology
1. Children
• congenital in origin
• most close spontaneously by age 2
• 8X more common in African-Americans


2. Adults
• acquired condition
• more common in women
• may result from conditions that increase intra-abdominal pressure: pregnancy, obesity, ascites, constipation, chronic cough


2. Management
• small, asymptomatic hernias do not need to be repaired
• all symptomatic hernias should be repaired
• defects < 3 cm in size can often be close primarily after excising the hernia sac
• larger defects are closed with a mesh patch placed in an inlay, onlay, or sublay position
• repairs may be done open or laparoscopically
• no universal consensus on the best method of repair


1. Umbilical Hernia Repair in Cirrhotics
• umbilical hernias in patients with ascites will continue to enlarge
• skin breakdown with spontaneous rupture of the hernia can result in peritonitis and death
• cirrhotics are often hypoalbuminemic and coagulopathic, making them high-risk surgical candidates
• historically, elective repair was contraindicated because of the high morbidity and mortality rates
• with modern preoperative and intraoperative management, serious complication rates are < 10%, making elective repair feasible for many patients



1. Preoperative Preparation
• includes free water restriction, diuretics, and large volume paracenteses (with infusion of albumin)
• some series report good results with perioperative placement of a temporary peritoneal dialysis catheter or transjugular intrahepatic portosystemic shunt
• there is no current indication for placement of a perioperative peritoneovenous shunt


2. Surgical Management
• use of synthetic mesh is not contraindicated, and is associated with lower recurrence rates (3%) than primary repairs (15%)
• both onlay and retrorectus sublay repairs give equivalent results
• venous abdominal wall collaterals should not be ligated because this can cause hepatic decompensation


2. Epigastric Hernias
1. Presentation
• more common in men
• located between the xiphoid process and the umbilicus
• usually are painful because they often contain incarcerated preperitoneal fat


2. Management
• repair is indicated, since most are symptomatic
• small hernias can be closed primarily, but larger lesions will require mesh


3. Diastasis Recti
• may be confused with an epigastric hernia
• is an area of weakness that results from the stretching of the linea alba
• presents as a diffuse midline bulge, but no true hernia defect is present
• abdominal US or CT scan can confirm the diagnosis
• does not require repair



3. Incisional Hernias
1. Etiology
• result from excessive tension and inadequate healing of an incision
• wound infections and hematomas greatly increase the risk of incisional hernias
• corticosteroids and chemotherapy drugs contribute to poor wound healing
• other risk factors include obesity, older age, malnutrition, ascites, diabetes, chronic pulmonary disease


2. Pathophysiology
• pain, bowel obstruction, incarceration, and strangulation may result
• large hernias may result in loss of abdominal domain


3. Nonoperative Management
• preferred option for asymptomatic or mildly symptomatic patients
• symptomatic patients with modifiable risk factors should also initially be managed nonoperatively
• patients with a BMI > 35 should be put on a weight loss program or may need to consider bariatric surgery before proceeding with hernia surgery
• patients will also need to quit smoking and get their diabetes under good control before considering elective surgery


4. Operative Repair
• almost all will require a mesh repair
• choice of mesh will depend on whether the mesh will be in direct contact with the bowel, and the presence or risk of infection
• the ideal mesh has yet to be developed


1. Types of Mesh
1. Polypropylene Mesh (Marlex)
• macroporous mesh that allows ingrowth of fibroblasts and incorporation into the surrounding fascia
• should not be placed in an intraperitoneal position, since bowel will adhere to it, resulting in a high rate of enterocutaneous fistulas


2. PTFE Mesh (Gortex)
• impermeable to fluid
• not incorporated into native tissue
• resists adhesion formation


3. Composite Mesh
• consists of a PTFE surface and a polypropylene surface
• PTFE side is placed against the bowel, and the polypropylene side is placed superficially and is incorporated into the native tissue
• since these materials have different rates of contraction, buckling of the mesh can occur, with resulting exposure of the polypropylene surface to the bowel


4. Biologic Mesh
• nonsynthetic, natural tissue mesh
• comes from human, bovine, or porcine sources
• composed of acellular collagen
• provides a framework for neovascularization and native collagen deposition
• typically used in infected or contaminated cases in which synthetic mesh is contraindicated
• functions best as a fascial reinforcement rather than as a bridge or interposition repair
• long-term durability of these products is unresolved


2. Mesh Placement
• basic concept is to place a piece of mesh larger than the defect with a wide overlap



1. Overlay Technique
• involves primary closure of the fascial defect (if possible), and placement of the mesh over the anterior fascia
• major advantage is that the mesh is not in contact with the bowel
• major disadvantages include large subcutaneous flaps, increased seroma formation, superficial location of the mesh with increased infection risk, and the increased tension from the primary closure
• reported recurrence rate is ~28%


2. Inlay Technique
• involves suturing the mesh to the fascial edges without overlap
• has the highest recurrence rate


3. Sublay Technique
• mesh is widely placed below the fascia
• mesh can be placed preperitoneally or retromuscularly
• intra-abdominal pressure will help to hold the mesh in place
• lower recurrence rate and complication rate than the overlay or inlay techniques


4. Intraperitoneal Mesh Placement
• laparoscopic repairs use intraperitoneal composite mesh placement secured with tacks or mattress sutures
• one advantage is the ability to widely place the mesh around the hernia defect (at least 4 cm)
• associated with fewer wound complications


3. Components Separation
• used to create an advancement flap of the rectus muscles towards the midline
• usually is augmented with mesh placed in an onlay or sublay position
• restores the linea alba, resulting in a more functional abdominal wall


1. Anterior Component Separation
• large subcutaneous flaps are raised above the external oblique fascia
• bilateral longitudinal relaxing incisions are made in the external oblique fascia 2 cm lateral to the semilunar line
• extent of the relaxing incision is from the costal margin to the pubis
• the external oblique is bluntly dissected away from the internal oblique, facilitating its advancement
• if necessary, additional release may be obtained by making a relaxing incision in the posterior rectus sheath
• up to 20 cm of mobilization can be obtained with these techniques
• common complication is wound breakdown from devascularized skin flaps caused by the extensive undermining required



2. Transversus Abdominis Release (TAR)
• TAR starts by entering the posterior rectus sheath and developing a retrorectus plane
• the lateral dissection is extended to 1 cm medial to the linea semilunaris preserving the neurovascular bundles innervating the medial abdominal wall
• the transversus abdominis muscle fibers are identified and divided to enter a retromuscular and preperitoneal plane
• the dissection is then continued laterally to the psoas muscle
• after bilateral TAR is completed, the posterior rectus sheath is closed in the midline to fully isolate the visceral contents from prosthetic mesh placement
• closure of the posterior rectus sheath also creates a space for the placement of a large piece of mesh in a sublay retromuscular position
• after mesh implantation, the rectus muscle and anterior rectus sheath are closed above the mesh to restore the midline abdominal wall



4. Complications
1. Mesh Infections
• PTFE mesh will need to be removed
• Marlex mesh can sometimes be salvaged with wound debridement and conservative excision of unincorporated mesh
• laparoscopic repairs are associated with a much lower incidence of wound complications


2. Seromas
• in open repairs, drains are usually placed to obliterate the dead space caused by dissecting out the hernia sac
• seromas commonly reform after the drains are removed
• drains are also a conduit for bacterial contamination of the mesh
• in laparoscopic repairs, since the hernia sac is not removed, seromas are inevitable
• wearing an abdominal binder 24 hours/day can minimize and prevent seroma formation


3. Bowel Injury
• may occur during adhesiolysis
• management depends on the type of bowel injured (small bowel vs colon), and the amount of spillage
• options include aborting the repair, primary tissue repair, using a biologic mesh, or delayed repair with synthetic mesh in 3 to 4 days
• the use of synthetic mesh in a grossly contaminated wound is contraindicated


5. Risk Factors for Recurrence After Repair
• recurrence rates after incisional hernia repair may be as high as 30%
• hernia width and contamination are the 2 most significant risk factors for recurrence
• hernia length, hernia location (midline versus lateral), and significant comorbidities (e.g., obesity, chronic obstructive pulmonary disease, diabetes, or smoking within 3 months of the operation) are not as important for predicting recurrence


6. Prevention of Incisional Hernias
1. Laparotomy Closure Technique
• the technique and choice of suture material influences incisional hernia rates
• slowly (6–9 months) absorbable suture (polydioxanone, PDS) is preferred over rapidly (2–3 months) absorbable suture (polyglactin, Vicryl)
• the rate of incisional hernias is lowest when small, closely spaced fascial bites are used
• 2 randomized trials using 2-0 polydioxanone and small, closely spaced fascial bites (5 mm deep and 5 mm apart) demonstrated the lowest incisional hernia rate
• prophylactic onlay mesh reinforcement of elective midline laparotomy incisions reduces incisional hernias but increases the rate of seromas and wound infections


4. Parastomal Hernias
1. Clinical Manifestations
• occurs in 50% of colostomies
• most are asymptomatic
• incarceration, bowel obstruction, or strangulation are rare
• routine repair is not recommended
• indications for repair include obstructive signs, difficulty applying an appliance, cosmesis


2. Repair Techniques
1. Primary Fascial Repair
• simplest option, but associated with the highest recurrence rate
• may be reinforced with mesh
• should only be used in patients who will not tolerate a laparotomy


2. Stoma Relocation
• predisposes patient to another parastomal hernia in the future
• new stoma site may be reinforced with synthetic or biologic mesh


3. Intraperitoneal Mesh Repair
1. Keyhole Technique
• hernia is reduced and the defect closed primarily
• the site is then reinforced with a large piece of mesh which surrounds the ostomy



2. Sugarbaker Procedure
• lateralizing the stoma redistributes the forces, minimizing hernia recurrence



5. Spigelian Hernias
1. Anatomy
• defect in the semilunar line, usually below the arcuate line (where the posterior rectus fascia ends)
• may also result from surgical drains or laparoscopic ports
• hernia sac is usually below the external oblique fascia (interparietal)



2. Clinical Presentation
• presents with localized pain but no bulge, because the hernia is below the intact external oblique fascia
• CT scan is usually required for the diagnosis
• should be repaired because of the high risk of incarceration



3. Repair
• may be repaired open or laparoscopically
• in an open repair, the transversus abdominis and internal obliques muscles are repaired, often without mesh