Spigelian Hernia: Symptoms, Types, Causes and Treatment

Spigelian hernia is a rare and often underdiagnosed condition that challenges both patients and physicians due to its subtle symptoms and unique anatomical location. While it accounts for a small fraction of abdominal wall hernias, its potential for serious complications—such as bowel obstruction and strangulation—makes awareness and early intervention essential. This article will guide you through the key symptoms, types, causes, and treatment options for Spigelian hernia, based on up-to-date clinical research and case studies.

Symptoms of Spigelian Hernia

Spigelian hernias are notorious for their elusive and variable presentation. Unlike more common hernias, their symptoms can be vague, intermittent, or even absent, which often leads to delays in diagnosis. Understanding the range of possible symptoms is crucial for patients and healthcare providers alike.

Symptom	Frequency/Presentation	Complications	Sources
Pain	Most common, often localized or intermittent	May signal incarceration or strangulation	1, 3, 5
Abdominal mass	Sometimes palpable, often intermittent or absent	Larger masses may indicate advanced hernia	1, 3, 12
Bowel obstruction	Less common, but serious; acute onset possible	Can indicate emergency situation	1, 3, 11
Asymptomatic	Incidental finding possible	Risk of sudden complication	1, 2, 13

Table 1: Key Symptoms

Pain: The Most Common but Nonspecific Symptom

Pain is the leading symptom of Spigelian hernia, reported in up to 60% of cases. It is typically localized to the site of the hernia, often lateral to the rectus muscle and below the umbilicus. The pain may be intermittent, especially early in the course of the hernia, and can be easily mistaken for other abdominal or musculoskeletal conditions. It often intensifies with movement or muscle contraction and may become constant if the hernia becomes incarcerated or strangulated 1 3 5.

Abdominal Mass: Elusive but Telling

A palpable mass is present in approximately 35% of cases. This mass may fluctuate in size, appearing more prominent when standing or straining and disappearing when lying down. However, due to the hernia’s deep anatomical location, even experienced clinicians may not always detect a mass on physical examination. Smaller hernias, especially, can be missed, underscoring the importance of imaging in diagnosis 1 3 12.

Bowel Obstruction and Acute Symptoms

In some patients, particularly when the hernia becomes incarcerated, symptoms escalate to signs of bowel obstruction—such as nausea, vomiting, abdominal distension, and constipation. These symptoms require urgent evaluation and intervention, as they may progress to bowel strangulation and necrosis, which can be life-threatening 1 3 11.

Asymptomatic Cases and Incidental Findings

Not all Spigelian hernias cause symptoms. A significant number are found incidentally during imaging or surgery for unrelated reasons. Asymptomatic cases still carry a risk of acute complications if undiagnosed and untreated 1 2 13.

Types of Spigelian Hernia

Spigelian hernias are not a single uniform entity. They vary in anatomical location, content, and clinical presentation, which influences both their diagnosis and management. Recognizing the different types helps guide appropriate treatment.

Type	Key Features	Patient Profile	Sources
Interstitial	Hernia sac remains beneath external oblique aponeurosis	Often younger adults	12, 8
Subcutaneous	Hernia sac penetrates through all muscle layers to subcutaneous tissue	May present as visible mass	3, 12
Richter-type	Only part of bowel wall herniates	Higher risk of strangulation	6, 7
Classic (Spigelian belt)	Occurs in 6-cm wide zone below umbilicus	Most common location	3, 8, 12

Table 2: Types of Spigelian Hernia

Interstitial Spigelian Hernia

The most common type, the interstitial Spigelian hernia, occurs when the hernia sac remains trapped beneath the external oblique aponeurosis. These hernias are particularly difficult to detect on physical exam and may not be visible externally. They are more common in relatively younger individuals and often present with only pain or subtle swelling 12 8.

Subcutaneous Spigelian Hernia

In these cases, the hernia sac passes through all layers of the abdominal wall and becomes subcutaneous, forming a visible and sometimes tender mass. This presentation is easier to diagnose clinically, but still requires imaging for confirmation and surgical planning 3 12.

Richter-type Spigelian Hernia

A rare but dangerous variant, the Richter-type involves only a portion of the bowel wall herniating through the defect. This can lead to bowel strangulation without classic signs of obstruction, making it a diagnostic challenge and a surgical emergency 6 7.

Classic Spigelian (Spigelian Belt) Hernia

Most Spigelian hernias are found in the so-called “Spigelian belt,” a 6-cm wide transverse zone just below the umbilicus and above the inferior epigastric vessels. This location is particularly susceptible due to anatomical weaknesses in the abdominal wall 3 8 12.

Causes of Spigelian Hernia

Understanding the causes of Spigelian hernia can help in both prevention and early detection. These hernias can arise due to a combination of congenital factors, acquired weaknesses, and certain risk factors.

Cause	Description	Risk Factors/Notes	Sources
Congenital	Defects present from birth	Seen in infants/children	8, 3
Acquired (Aging, Trauma)	Weakening of abdominal wall over time or after injury	More common in older adults	3, 12
Increased intra-abdominal pressure	Obesity, chronic cough, pregnancy, ascites	Repeated strain on abdominal muscles	3, 8
Iatrogenic	Complications from surgery (e.g., trocar sites)	Laparoscopic procedures	4, 8

Table 3: Causes of Spigelian Hernia

Congenital Defects

Some Spigelian hernias are congenital, resulting from developmental weaknesses in the abdominal wall. These are more frequently seen in pediatric populations, especially in neonates and infants 8 3.

Acquired Weaknesses

The majority of cases in adults are acquired. Aging leads to natural weakening of the abdominal wall, while trauma (including surgical incisions) can create new sites of weakness. Over time, even small defects can widen under pressure, allowing herniation to occur 3 12.

Increased Intra-abdominal Pressure

Any condition that chronically increases intra-abdominal pressure can predispose an individual to Spigelian hernia. Major contributors include:

• Obesity
• Chronic cough (e.g., from pulmonary disease)
• Multiple pregnancies
• Ascites
• Straining due to constipation or heavy lifting

These factors can act alone or in combination, progressively stretching the abdominal wall and facilitating hernia formation 3 8.

Iatrogenic Causes

Spigelian hernias can also be the unintended consequence of medical procedures. Laparoscopic surgeries that use trocars (instruments inserted into the abdominal wall) or placement of drains can weaken the Spigelian fascia and create potential hernia sites, especially if not properly closed afterward 4 8.

Treatment of Spigelian Hernia

Prompt and effective treatment of Spigelian hernia is essential to prevent serious complications. Surgery is the mainstay of management, but techniques have evolved with advances in both open and minimally invasive procedures.

Treatment	Indication	Advantages/Considerations	Sources
Open repair	Emergency cases, large hernias, unclear diagnosis	Direct visualization, suitable for all sizes	1, 3, 13
Mesh repair	Most elective repairs	Reduces recurrence risk	1, 15
Laparoscopic repair	Elective, smaller hernias, day surgery	Less pain, quicker recovery	1, 12, 14, 15
Emergency surgery	Incarceration, strangulation, obstruction	Life-saving, may require bowel resection	3, 11, 13

Table 4: Treatment Approaches

Open Surgical Repair

Open repair remains the traditional approach, especially for larger hernias, emergency presentations, or when the diagnosis is unclear. Surgeons can directly visualize the defect and contents, repair the hernia with sutures or mesh, and assess for any bowel compromise or necrosis 1 3 13.

Mesh Repair

The use of mesh (synthetic or biologic) has become standard in most elective repairs, as it provides a tension-free closure and significantly lowers the risk of recurrence. Newer prosthetic devices, such as the preperitoneal and subfascial mesh systems (e.g., PHS mesh), have made repairs easier and more comfortable for patients, often allowing for day surgery under local anesthesia 1 15.

Laparoscopic Repair

Laparoscopic surgery is increasingly favored for elective cases, especially for smaller and uncomplicated hernias. The minimally invasive approach offers several advantages:

• Reduced postoperative pain
• Shorter hospital stay (often same-day discharge)
• Faster return to normal activities

Totally extraperitoneal and intraperitoneal onlay mesh placements are common techniques. However, very large hernias or complicated cases may not be suitable for laparoscopy 1 12 14 15.

Emergency Surgery and Complications

When a Spigelian hernia becomes incarcerated or strangulated, emergency surgery is mandatory. Delay in treatment can lead to bowel obstruction and necrosis, sometimes requiring removal of non-viable bowel segments. Early diagnosis and prompt intervention are crucial to minimize morbidity and mortality 3 11 13.

Conclusion

Spigelian hernia, though rare, poses significant diagnostic and therapeutic challenges due to its subtle symptoms, variable presentation, and potential for serious complications. Awareness among both patients and physicians is key to timely diagnosis and effective management.

Key Points:

• Symptoms are often vague, with pain and occasional mass being the most common; many cases are asymptomatic or discovered incidentally.
• Types include interstitial, subcutaneous, Richter-type, and classic Spigelian belt hernias, each with unique features and risks.
• Causes range from congenital defects to acquired factors like aging, increased intra-abdominal pressure, obesity, and surgical trauma.
• Treatment is primarily surgical, with open, mesh-based, and laparoscopic repairs tailored to the individual case; emergency intervention is vital if incarceration or strangulation occurs.

Greater awareness and prompt intervention can prevent complications and improve outcomes for those affected by this rare but important condition.