Definition and etiology of abdominal hernias
Hernia is the protrusion of internal organs covered by the parietal peritoneum from the abdominal cavity through natural or artificial orifices of the anterior abdominal wall. This condition is encountered in the practice of any general surgeon, making the knowledge of hernia diagnosis and treatment principles a core part of training.
Etiologically, two groups of factors are distinguished:
- Predisposing factors include connective tissue dysplasia syndrome, nerve damage innervating the abdominal wall, and the presence of postoperative scars.
- Precipitating factors are conditions that increase intra-abdominal pressure: heavy physical labor, prolonged constipation, difficult urination, and chronic cough.
A hernia forms when both groups of factors combine: a weakened abdominal wall cannot withstand the increased intra-abdominal pressure.
Structure and types of hernias
Anatomically, a hernia consists of three components: hernial ring (defects in the musculo-aponeurotic layer), hernial sac (protrusion of the parietal peritoneum), and hernial contents (intestinal loops, greater omentum, and other organs).
Based on localization, hernias are divided into external and internal:
- External hernias protrude through orifices in the musculo-aponeurotic layer of the anterior or posterior abdominal wall, as well as the pelvic floor. These include inguinal, femoral, umbilical, linea alba, lumbar, obturator, and sciatic hernias.
- Internal hernias form inside the abdominal cavity (in peritoneal recesses) or penetrate into the thoracic cavity through natural or acquired diaphragmatic orifices. These include intra-abdominal and diaphragmatic hernias.
Clinical presentation and classification
Classic symptoms of a hernia include: the presence of a hernial protrusion revealed during straining or coughing in a standing position; palpable hernial ring; pain in the hernia area; and functional impairment of the organs within the hernial sac.
Clinical classification:
- Reducible hernia — the contents of the sac freely return to the abdominal cavity upon manual pressure.
- Irreducible hernia (complete or partial) — organs do not return to the abdominal cavity due to adhesive processes.
- Strangulated hernia — an acute surgical condition. Types include elastic strangulation, fecal strangulation, Richter's hernia (partial enterocele), retrograde strangulation, Meckel's diverticulum strangulation (Littre's hernia), and Broca's hernia.
An irreducible hernia and delayed patient presentation are the main risk factors for strangulation.
Differential diagnosis
A hernia must be differentiated from two conditions:
- Eventration is the protrusion of organs through an acutely developed defect in the abdominal wall without preservation of the integrity of the parietal peritoneum. It most commonly occurs in the postoperative period due to the dehiscence of a laparotomy wound. Eventration lacks a hernial ring and a hernial sac.
- Prolapse is the protrusion of internal organs not covered by peritoneum through natural orifices. Typical examples include uterine prolapse and rectal prolapse.
Treatment: conservative and surgical
Conservative treatment includes limiting physical exertion and wearing a truss. It has limited application — when the patient refuses surgery or has contraindications (severe comorbidities, pregnancy). The only radical method is surgical intervention.
Surgical treatment consists of three main stages:
- Access — open or laparoscopic; the choice depends on hernia localization, surgical convenience, and the surgeon's qualifications.
- Revision of the hernial sac — opening the sac and assessing the condition of its contents (especially intestinal loops). If there are signs of necrosis, the affected area is resected, and viable organs are returned to the abdominal cavity. Then, the sac is sutured and excised.
- Hernioplasty — closure of the abdominal wall defect.
Types of plasty:
- Autoplasty — using the patient's own tissues: muscular, musculo-aponeurotic, fascial-aponeurotic.
- Alloplasty — using synthetic (polypropylene mesh) or biological materials. Modern mesh implants are chemically inert, non-rejectable, and do not cause transplant complications.
- Combined plasty — a combination of native tissues and prosthetic materials.
Key points
- Hernia — the protrusion of organs covered by the parietal peritoneum through an abdominal wall defect.
- Etiology combines predisposing factors (tissue weakness) and precipitating factors (increased intra-abdominal pressure).
- Anatomical components: hernial ring, hernial sac, and its contents.
- Hernias are divided into external and internal; clinically into reducible, irreducible, and strangulated.
- Strangulation is an acute condition requiring emergency surgery.
- Eventration and prolapse differ from hernias by the absence of a hernial sac and peritoneal coverage.
- Conservative therapy is supportive; the primary method is surgery.
- Surgical treatment includes access, sac revision, and defect plasty using auto- or allografts.