Reducible
The hernia contents can return into the abdominal cavity, spontaneously or with appropriate clinical manipulation.
TEXTBOOK READER
Incisional Hernia
A structured guide to abdominal wall anatomy, how incisional hernias form, clinical presentation, diagnosis, preoperative planning, operative principles, postoperative recovery, complications, fascial dehiscence, and long term follow up.
Clinical safety note. New severe abdominal pain, a firm or irreducible bulge, vomiting, bowel obstruction symptoms, a rapidly changing postoperative wound, suspected fascial dehiscence, or evisceration can represent an urgent surgical problem and needs prompt professional evaluation.
Chapter 1
Abdominal Wall Anatomy
The abdominal wall is a layered mechanical structure that protects the abdominal cavity, contributes to trunk motion, and transmits forces generated by the abdominal muscles. The exact anatomy changes from region to region, but a simplified superficial to deep sequence is skin, subcutaneous tissue, fascial and aponeurotic layers, muscle, deeper fascia and preperitoneal tissue, and peritoneum.
SkinExternal protective covering
Subcutaneous tissueFat and connective tissue beneath the skin
Fascial and aponeurotic layersDense connective tissue that transmits and distributes force
MuscleIncludes rectus abdominis and the lateral abdominal wall muscles
Deep fascia and preperitoneal tissueDeeper supporting tissue planes
PeritoneumSerous lining of the abdominal cavity
Why fascia matters
The fascial and aponeurotic layer is a major load bearing component of an abdominal incision closure. If the healing process or closure fails, the abdominal wall may lose continuity. Early separation is called fascial dehiscence. A later persistent defect at an old incision is an incisional hernia.
Key distinction: Fascial dehiscence is an acute postoperative failure of a previously closed fascial layer. An incisional hernia is generally a later persistent weakness or defect at a previous operative site. They are related, but they are not synonyms.
Chapter 2
Definition and Classification
An incisional hernia is a hernia occurring at or near a previous surgical incision because the abdominal wall at that site has developed a weakness or defect. It may appear months or years after an operation, although many become noticeable within the first year. A common presentation is a bulge that becomes more apparent with standing, coughing, or straining.
Incarcerated
The hernia contents are trapped and cannot be reduced. Incarceration raises concern for obstruction and other complications but does not by itself prove ischemia.
Strangulated
Blood flow to trapped tissue is compromised. Strangulation is a surgical emergency.
Defect anatomy
Hernia descriptions can include location, width and length of the defect, whether multiple defects exist, the contents of the hernia, and whether the abdominal wall is distorted by a large chronic hernia. Large complex defects can involve loss of domain, in which a substantial amount of abdominal content has chronically resided outside the normal abdominal cavity.
Chapter 3
Risk Factors and Pathophysiology
Incisional hernia formation results from the interaction of tissue healing, surgical technique, wound complications, mechanical loading, and patient factors. After an incision is closed, collagen is produced and remodeled over time. The healing wound initially has limited mechanical strength, then gradually becomes stronger as matrix is reorganized.
| Factor | Relationship to healing or hernia formation |
|---|---|
| Wound infection | Inflammation and tissue injury can weaken or disrupt the repair. |
| Smoking or tobacco exposure | Can impair tissue oxygenation and wound healing. |
| Diabetes or poor glycemic control | Can increase infection risk and interfere with healing biology. |
| Malnutrition | Healing requires adequate energy, protein, oxygen delivery, and micronutrients. |
| Obesity | Changes abdominal wall mechanics and is associated with wound complications. |
| Chronic corticosteroid exposure | Can interfere with inflammatory and collagen related healing processes. |
| Emergency or contaminated surgery | May increase physiologic stress, contamination, and wound complication risk. |
| Increased intraabdominal pressure | Coughing, ileus, obstruction, ascites, and straining can load a healing closure. |
Study principle: A surgical wound is a biologic repair process under mechanical load. Poor healing conditions plus mechanical stress can leave a permanent weakness.
Chapter 4
Clinical Presentation
The classic finding is a bulge at or close to an old surgical scar. Some people have no symptoms other than the bulge. Others experience pressure, aching, pain with activity, movement limitations, or symptoms related to bowel involvement.
History
Relevant history includes the original operation and incision, timing of the bulge, whether it changes with position or straining, reducibility, pain, bowel symptoms, prior repairs or mesh, previous wound infection or dehiscence, and conditions that may affect wound healing.
Examination
Assessment can include inspection and palpation in clinically appropriate positions. The examiner considers the location and estimated size of the defect, tenderness, reducibility, overlying skin, and findings that could indicate obstruction or compromised bowel.
Red flags: severe or rapidly worsening pain, marked tenderness, a firm or irreducible bulge, vomiting, abdominal distension, fever with concerning wound changes, or new discoloration can indicate a complication requiring urgent assessment.
Chapter 5
Diagnosis and Imaging
Many incisional hernias are diagnosed clinically. Imaging can be helpful when the diagnosis is uncertain, when the abdominal wall is difficult to assess, when a complex or recurrent defect is suspected, or when detailed anatomy is needed for operative planning.
Physical examination
Defines the palpable defect, symptoms, reducibility, and wound findings.
Ultrasound
Can evaluate the abdominal wall dynamically and may help characterize smaller defects.
CT
Provides cross sectional anatomy, defect dimensions, hernia contents, and relationships useful in complex planning.
Questions imaging can answer
Where is the defect? How large is it? Are there multiple defects? What structures are within the hernia? Is there loss of domain? Is there evidence of obstruction, inflammation, abscess, or another abdominal process? Imaging should be selected to answer a clinical question.
Chapter 6
Preoperative Evaluation
Elective repair planning considers both the abdominal wall defect and the patient's readiness for surgery. The goal is not simply to close a hole. Surgeons also plan for wound healing, recurrence prevention, functional restoration, anesthesia needs, and postoperative recovery.
Hernia assessment
- Symptoms and functional impact
- Defect location and dimensions
- Single versus multiple defects
- Reducibility and contents
- Previous repairs and mesh
Risk optimization
- Tobacco exposure
- Nutrition
- Glycemic control
- Cardiopulmonary status
- Medication review
Operative planning
- Open, laparoscopic, robotic, or hybrid approach
- Expected fascial closure
- Mesh plane and coverage
- Need for abdominal wall reconstruction
- Adhesion and prior mesh considerations
Recovery planning
- Pain control
- Mobilization
- Wound care
- Activity guidance
- Follow up and warning signs
High yield: Preoperative optimization is part of the surgical process. Nutrition, tobacco exposure, diabetes, pulmonary status, medications, and active wound problems can all affect risk.
Chapter 7
Surgical Repair Principles
Repair is individualized to the defect and patient. Open, laparoscopic, robotic, and hybrid approaches are used in modern abdominal wall surgery. In appropriate incisional hernias, mesh reinforcement is commonly used because it can distribute load across a broader area than a suture only repair.
Core objectives
- Define the defect and relevant abdominal wall anatomy.
- Protect abdominal contents and address adhesions as appropriate.
- Restore fascial continuity when feasible and avoid excessive closure tension.
- Use reinforcement and tissue planes suited to the defect, contamination status, and patient.
- Limit unnecessary tissue trauma, dead space, and wound complications.
Mesh concepts
Mesh can reinforce the abdominal wall and distribute load. Choice of material, plane, size, fixation, and approach depends on anatomy, contamination, prior surgery, defect complexity, and surgeon experience. Complex abdominal wall reconstruction may require advanced techniques such as component separation.
Educational boundary: This section describes surgical principles, not a step by step operative manual. Actual operative technique belongs in supervised surgical education and depends on patient specific findings.
Chapter 8
Postoperative Recovery
After repair, care centers on physiologic stability, pain control, respiratory function, mobilization, hydration and nutrition, bowel recovery, wound surveillance, and recognition of complications. The exact course depends on the operation and the patient's condition.
Early
Stability and monitoring
Vital signs, pain, nausea, respiratory status, abdominal findings, urine output, and the operative wound are monitored.
Hospital
Recovery and mobilization
Gradual activity, appropriate intake, bowel recovery, pulmonary hygiene, and prevention of postoperative complications are considered.
Discharge
Home recovery
Follow wound care instructions, use the prescribed pain plan, gradually resume activity as directed, and attend follow up.
Wound surveillance
Soreness and mild swelling can occur after surgery. Concerning changes include increasing redness, purulent drainage, fever, increasing swelling, unexpected wound separation, severe or escalating pain, or a new bulge accompanied by concerning symptoms.
Activity
Postoperative lifting and activity restrictions vary with the procedure and surgeon's technique. A universal lifting limit should not be assumed. The operative team’s instructions take precedence.
Chapter 9
Complications
| Complication | What it means |
|---|---|
| Seroma | A postoperative collection of serous fluid, often in a space created by dissection. |
| Hematoma | A collection of blood that can increase pain, tissue tension, and infection risk. |
| Surgical site infection | Infection of the incision or deeper operative field that can impair healing and affect a mesh repair. |
| Superficial wound dehiscence | Separation of superficial wound layers without necessarily involving the fascial closure. |
| Fascial dehiscence | Separation of the previously closed abdominal fascia after surgery. |
| Chronic pain | Pain persisting beyond the expected healing period; causes can be multifactorial. |
| Recurrence | Return of a hernia after repair. |
| Obstruction or strangulation | Hernia contents may become trapped, obstruct the bowel, or in strangulation lose adequate blood supply. |
Chapter 10
Fascial Dehiscence
Fascial dehiscence is separation of a previously sutured abdominal fascial closure during postoperative healing. It is a serious complication because loss of abdominal wall integrity can progress to evisceration, bowel obstruction, infection, and a later incisional hernia.
Typical timingMost often recognized within the first 1 to 2 weeks after surgery.
Classic warning featuresNew or markedly increased wound drainage, a new abdominal wall bulge, or a sudden popping or pulling sensation can be clues.
Major concernEvisceration requires emergent surgical evaluation.
Risk factors
Evaluation
Early surgical involvement is important. When the diagnosis is uncertain and the skin remains intact, CT can help define the fascial defect and identify associated pathology. The NCBI Bookshelf review emphasizes avoiding unnecessary bedside opening of an intact skin closure because this may precipitate evisceration.
Urgency: Suspected fascial dehiscence is not a routine follow up issue. New concerning postoperative wound changes need prompt clinical assessment, especially when evisceration, obstruction, ischemia, or systemic illness is possible.
Relationship to incisional hernia
Fascial dehiscence and incisional hernia can lie on the same causal pathway. An early fascial failure can leave the abdominal wall with a persistent defect, but many incisional hernias develop without a documented acute dehiscence.
Management overview
Management depends on the wound, infection status, tissue quality, abdominal pressure, evisceration, bowel involvement, and physiologic stability. Complicated cases may need urgent operative repair and, in selected circumstances, temporary or staged abdominal wall strategies.
Chapter 11
Recurrence and Long Term Follow Up
Repair does not remove every factor that contributed to the original defect, so recurrence remains possible. Long term follow up considers symptoms, abdominal wall contour, function, wound history, and modifiable risk factors.
Why recurrence happens
Recurrence can reflect defect complexity, tissue quality, wound infection, mechanical stress, healing biology, patient factors, or technical factors. It is best understood as a multifactorial outcome rather than a single event with a single cause.
Patient factors+Defect anatomy+Healing biology+Repair strategy+Follow up
Chapter 12
Glossary
- Aponeurosis
- A broad sheet of connective tissue that attaches muscle to other structures.
- Fascia
- Connective tissue that supports, separates, and integrates muscles and other structures.
- Fascial dehiscence
- Separation of a previously sutured fascial surgical layer.
- Evisceration
- Protrusion of abdominal viscera through an open surgical wound; a surgical emergency.
- Incarceration
- A hernia whose contents cannot be reduced into the abdominal cavity.
- Strangulation
- Compromise of the blood supply to entrapped hernia contents.
- Loss of domain
- A condition in which a substantial portion of abdominal contents chronically resides outside the usual abdominal cavity.
- Component separation
- A group of abdominal wall reconstruction techniques that mobilize musculofascial layers to facilitate closure.
- Seroma
- A collection of serous fluid, commonly forming in a postoperative dead space.
- Recurrence
- Return of a hernia after repair.
Chapter 13
High Yield Review
Incisional hernia: a weakness or defect at a previous surgical incision.
Fascial dehiscence: postoperative separation of a previously closed fascial layer.
Timing distinction: dehiscence is an early wound failure; incisional hernia is usually a persistent or later defect.
Preoperative framework: define the anatomy, assess symptoms and complexity, optimize modifiable risk factors, and plan the repair.
Postoperative framework: monitor the wound, support physiologic recovery, mobilize as instructed, and recognize complications early.
Emergency framework: strangulation, obstruction, evisceration, and suspected fascial dehiscence require prompt professional assessment.
References
Selected Sources
This site uses original educational wording and summarizes source material. It does not reproduce NCBI Bookshelf chapters.
- Andronic F, Sequeira Campos MB, Sandhu R. Fascial Dehiscence. StatPearls. NCBI Bookshelf. Updated January 23, 2026.
- Institute for Quality and Efficiency in Health Care. How are incisional hernias treated? InformedHealth.org. NCBI Bookshelf. Updated December 13, 2023.
- Sanders DL, Pawlak MM, de Beaux AC, et al. European Hernia Society guidelines on the treatment of midline incisional hernias. British Journal of Surgery. 2023;110(3):343.
- Bordoni B, Mahabadi N, Jozsa F. Anatomy, Fascia. StatPearls. NCBI Bookshelf. Updated December 9, 2025.
Important: medical knowledge changes. For clinical decisions, use current professional guidelines and the treating team's instructions.