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INGUINAL HERNIAS DIAGNOSIS, INDICATIONS AND TREATMENT |
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JB Flament, MD, Centre Hospitalier Universitaire de Reims, Reims, France |
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1. Introduction 2. Anatomical basics 3. Topological forms 4. Etiology 5. Types/contents 6. Diagnosis 7. Complications 8. References |
1.
Introduction
A hernia is a diverticulum of the parietal peritoneum (hernia sac), usually containing viscera. Hernias develop through an opening or natural weakness in the abdominal wall. The hernia sac communicates with the greater peritoneal cavity via a narrower segment, the hernia neck. The bulge of the hernia progressively increases in size as a result of abdominal pressure. |
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1. Introduction 2. Anatomical basics 3. Topological forms 4. Etiology 5. Types/contents 6. Diagnosis 7. Complications 8. References |
2.
Anatomical basics
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;) Figure 2.2 1. Pectineal (Cooper’s) ligament 2. Internal oblique muscle 3. Transversus abdominus muscle 4. Psoas muscle 5. Lateral border of the rectus muscle 6. Inguinal ligament 7. Transversalis fascia |
2.3. Transversalis fascia
This structure corresponds to the deep layer of the transverse muscle aponeurosis; it inserts inferiorly on the pectineal ligament. The fascia gives rise to 2 sheaths that cover the anatomical elements passing through the myopectineal orifice. In the inguinal pane, the transversalis fascia evaginates around the spermatic cord to form the common fibrous sheath. In the femoral pane, the transversalis fascia gives rise to a funnel-shaped structure surrounding the femoral vessels, and extends to form the vascular sheath. The transversalis fascia has several connective reinforcements: the interfoveolar ligament, condensation of connective tissue surrounding the inferior epigastric vessels in the internal ring, and the iliopubic tract, which runs parallel to the inguinal ligament.
;) Figure 2.3 1. Deep layer of the transverse muscle aponeurosis 2. Common fibrous sheath |
2.4. Inguinal fossae
The superior inguinal pane of the myopectineal orifice is bounded superiorly by the inferior border of the internal oblique muscles and inferiorly by the inguinal ligament. It presents 3 fossae. The lateral inguinal fossa is lateral to the inferior epigastric artery reinforced by the interfoveolar ligament. The internal ring opens at this level, creating a passageway for the spermatic cord in males and the round ligament in females. The middle inguinal fossa is situated between the contours of the inferior epigastric artery laterally, and the umbilical artery medially. The medial inguinal fossa is situated between the umbilical artery laterally and the urachus medially.The inferior femoral pane is filled in its lateral compartment by the iliopsoas muscle, reinforced medially by the pectineal ligament. The medial compartment is the only weak point of the region: it is the femoral ring, delimited laterally by the psoas muscle, inferiorly by the superior pubic ramus (pectineal line) lined by the pectineal ligament, superiorly by the inguinal ligament, and medially by the lacunar ligament made up of the most medial fibers of the external oblique muscle. It is the passageway of the femoral pedicle.
;) Figure 2.4 1. Lateral inguinal fossa 2. Middle inguinal fossa 3. Medial inguinal fossa |
1. Introduction
2. Anatomical basics
3. Topological forms
4. Etiology
5. Types/contents
6. Diagnosis
7. Complications
8. References
3.
Topological forms of groin hernias
3.1. Inguinal hernias
Inguinal hernias appear above the inguinal ligament and develop in the inguinal canal.Indirect hernias pass through the internal ring laterally to the inferior epigastric vessels. In males, they course parallel to the spermatic cord and develop toward the testicles. In females, they course parallel to the round ligament and develop toward the labia majora.
Direct hernias usually pass through the transversalis fascia at the level of the middle inguinal fossa, medial to the inferior epigastric artery. Internal oblique hernias, which are very rare, are considered to be anatomical oddities. They pass through the transversalis fascia in the medial inguinal fossa area between the umbilical artery and the urachus.
;) Figure 3.1 1. Indirect hernias 2. Direct hernias |
3.2. Femoral hernias
Femoral hernias develop through the femoral ring, usually medial to the femoral vessels. Squeezed inside a rigid ring (inguinal ligament superiorly, pectineal ligament inferiorly and lacunar ligament medially), they are often small in volume, and are therefore difficult to diagnose. Strangulation complications are common.In very rare cases, they can appear anterior or lateral to the femoral vessels. These are prevascular hernias.
;) Figure 3.2 |
1. Introduction
2. Anatomical basics
3. Topological forms
4. Etiology
5. Types/contents
6. Diagnosis
7. Complications
8. References
4.
Etiology of groin hernias
4.1. Congenital hernias
These are derived from the persistence of all or part of the processus vaginalis of the peritoneum. Other anatomical elements of the region are normal. The processus vaginalis is closed at birth in 40% of newborns, and can close in other children during their first year. In boys, the processus vaginalis permits communication between the peritoneal cavity and the tunica vaginalis. In girls, patency of the peritoneal process that accompanies the round ligament (the canal of Nuck) is often associated with ectopia of the ovary which may lead to a hernia of the ovary and of the Fallopian tube. Normal closure of the processus vaginalis leaves a remnant called Cloquet’s ligament.Congenital hernias occur through the internal ring and as such are always indirect hernias. They are found in infants, children and teenagers, but can also appear in young adults, usually after physical exertion linked to an athletic activity. In children or young adults, they can be accompanied by vestigial formations such as a spermatocele or vaginal hydrocele.
4.2. Acquired hernias or hernias from weakness
These hernias appear in adults or the elderly due to a weakness in the muscular and aponeurotic structures. They are more common in men, and occur as a result of a combination of different factors:-
factors that contribute to the weakening of the musculo-aponeurotic structures: age, sedentary lifestyle, obesity or massive weight loss and multiple pregnancies. Collagen synthesis disorders sometimes contribute to the process. Histological studies of patients with hernias have revealed a lipomatous degeneration, a conjunctive neovascularization and a disorganization of the aponeurotic and tendinous fibers. Hernias due to weakness always occur as the consequence of a weakness of the transversalis fascia,
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factors of excessive intra-abdominal pressure, whether linked to pathological circumstances (chronic cough, constipation, dysuria, ascites) or to repeated physical exertion (related either to work or sports).
4.3. Nyhus classification
The distinction between congenital hernias and hernias due to weakness is not sufficient to describe all types of hernias. The Nyhus classification ( Nyhus, 1989; Nyhus et al., 1991 ) distinguishes between:-
type I corresponding to an indirect hernia with a normal internal ring;
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type II corresponding to an indirect hernia with an enlarged internal ring, but with a normal inguinal floor;
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type III is subdivided into 3 categories: direct hernias (IIIa), the combination of indirect and direct hernias (IIIb) and femoral hernias (IIIc);
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type IV hernias are recurrent hernias. They can be direct (IVa), indirect (IVb), femoral (IVc) or a combination of different anatomical types (IVd).
;) Figure 4.3 1. Deep inguinal ring 2. Superficial inguinal ring 3. Inguinal canal |
1. Introduction
2. Anatomical basics
3. Topological forms
4. Etiology
5. Types/contents
6. Diagnosis
7. Complications
8. References
5.
Types of hernias according to contents
Mobile organs and neighboring organs can join in the hernia sac: the small bowel is frequently involved, the greater omentum results in an omentocele and the colon results in voluminous inguino-scrotal hernias on the left side. The colon can give rise to sliding hernias; in this case, the adhering fascia (ie, the left Toldt’s fascia) descends along with the colon, and there is no sac at this level. If this has not been identified, there is a danger of colic injury during surgery.The bladder is almost always involved in wide-necked direct hernias. The hernia may have to be reduced in order for the patient to micturate. An intravenous urography can reveal an intra-hernial bladder diverticulum.
On the right, the whole appendix or just its tip may be found in the hernia sac. Complete sliding of the cecum may occur when the hernia is voluminous.
The presence of a Meckel’s diverticulum in the hernia sac leads to a classic Littré's hernia.
In cirrhotic patients, the hernia contents may be represented by ascites fluid. When the patient is standing, these hernias are voluminous, but they empty when the patient lies down.
;) Figure 5 |
1. Introduction
2. Anatomical basics
3. Topological forms
4. Etiology
5. Types/contents
6. Diagnosis
7. Complications
8. References
6.
Diagnosis
6.1. Symptoms
Hernia diagnosis is essentially done by physical examination.Generally, the patient consults for a lump in the groin. The physician should find out when the lump appeared, and if it appeared progressively or abruptly and with pain following a physical effort or while coughing, defecating or urinating.
This swelling can cause functional problems ranging from a simple feeling of discomfort to true pain linked to straining, affecting the patient’s activities. Occasionally, there is no visible swelling and the symptomatology is limited to pain in the region of the groin, inguinal canal or testicles in males.
6.2. Physical examination
The physical examination should be methodological. The patient should first be examined standing and then lying down, and should be asked to cough in order to increase intra-abdominal pressure and favor protrusion of the hernia. Although sometimes there may be no visible signs during the examination, the swelling is usually obvious. Its size and reaction to coughing should be assessed.The anatomical landmarks of the region are searched for during palpation: Malgaigne’s line, a cutaneous projection of the inguinal ligament from the anterior superior iliac spine and superior to the pubic tubercle, followed by the femoral vessels whose beating can be perceived slightly lateral to the midline of the inguinal ligament. The character of the swelling can also be evaluated by palpation. A hernia that is not complicated is reducible and is reproducible when the patient coughs.
The contents of the sac are also assessed. In most cases, these are either the omentum with a coarse consistency, or the intestine with a soft consistency, which gurgles as it is being reduced.
At the end of the physical examination, it is usually easy to distinguish between an inguinal hernia and a femoral hernia.
6.3. Inguinal hernias
Inguinal hernias occur most frequently in males over 50. They develop in the inguinal canal above Malgaigne’s line.In males, the skin of the scrotum (equivalent to the size of a finger) is pushed through the external ring during the examination. Whether it penetrates or not into the abdomen through the internal ring reveals the degree of tonicity and the solidity of the transversalis fascia and abdominal muscles.
In females, the hernia ring is found cephalad and lateral to the pubic tubercle. When it is voluminous, the hernia develops toward the labium majus along the course of the round ligament of the uterus.
Depending on how developed the hernia is, the following terms are used:
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hernia tip when the sac appears at the internal ring and is only visible when the patient coughs;
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interstitial hernia when the sac extends into the inguinal canal;
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bubonocele when the hernia appears at the external ring;
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funicular hernia when it descends along the spermatic cord;
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inguino-scrotal hernia when the hernia extends into the scrotum. This can become extremely large, resulting in the disappearance of the foreskin of the penis, which becomes part of the cutaneous covering of the hernia.
Diagnosing an inguinal hernia is usually straightforward if the clinical examination is performed properly.
Nevertheless, the surgeon may sometimes be led to question certain differential diagnoses. A vaginal hydrocele may mimic a voluminous inguino-scrotal hernia; its non-responsiveness to coughing and a transillumination test can generally differentiate it. A small inguinal hernia may be mistaken for a varicocele or a tumor in the soft parts of the region. Finally, an eventration at the edge of a scar following a suprapubic Pfannenstiel incision (commonly used in gynecological procedures) may be clinically difficult to distinguish from a groin hernia. The operation, which is required in any case, will rectify the diagnosis.
;) Figure 6.3 |
6.4. Femoral/crural hernias
Femoral hernias are much rarer than inguinal hernias. They are found more frequently in female patients (75% of cases), but can be very conspicuous in male patients.These direct hernias pass through the femoral canal, generally medial to the femoral vessels. As they are confined in a narrow channel with rigid walls, they are relatively small in most cases, accounting for the fact that they often go unnoticed until they become strangulated.
Femoral hernias typically cause a lump at the root of the thigh within the sheath of the femoral artery, inferior to Malgaigne’s line. The lump is often difficult to detect, especially in obese female patients. To check for a femoral hernia, the patient’s thigh should be abducted and placed in external rotation. The hernia may be reducible and cough-responsive, but in a great many cases it is non-reducible due to the fixation of its contents in the sac.
A femoral hernia must be differentiated from a branch of a dilated or thrombotic internal saphenous vein, a lipoma, a femoral artery aneurysm, and especially from adenopathy.
;) Figure 6.4 |
1. Introduction
2. Anatomical basics
3. Topological forms
4. Etiology
5. Types/contents
6. Diagnosis
7. Complications
8. References
7.
Complications
7.1. Strangulated hernia
All types of hernias may become strangulated.The incidence of strangulation is highest in f emoral hernias and inguinal hernias with a large sac and narrow neck. It corresponds to the constriction of the hernial contents at the level of the neck: constriction of an intestinal loop and of its mesentery, occasional constriction of the antimesenteric border of the bowel creating lateral pinching (Richter hernia) or strangulation of an omental tongue (omentocele).
Clinically, the hernia becomes full and taut, painful, non-reducible and loses its cough-responsiveness. These clinical signs mandate emergency surgical intervention before the onset of obstruction and sepsis.
If the bowel is involved, the hernial strangulation leads to mechanical obstruction by strangulation, responsible for bowel ischemia that develops within hours into irreversible necrosis and visceral perforation. The perforation can occur in the hernial sac, resulting in a classical purulent stercoral, or in the peritoneal cavity with the resulting clinical picture of acute generalized peritonitis.
The prognosis of a strangulated femoral hernia is poor. This complication is often seen. The hernia becomes painful, fixed and non-reducible, but occasionally the patient does not complain about the hernial region. In 50% of cases, the obstructive syndrome is predominant. The surgeon must then look for a small hernia concealed in the inguino-femoral fold. The severity of this complication should prompt the surgeon to consider any painful lump in the region as a strangulated hernia requiring surgical exploration.
;) Figure 7.1 |
7.2. Obstructed hernia
This is a minor form of strangulation, generally reducible or partially reducible either spontaneously or using gentle reinsertion maneuvers. Local hernial manipulations are generally not accompanied by abdominal signs. Hernial obstruction should not be confused with the non-reducible character of a hernia related to possible intrasaccular adhesions or to the large bulk of herniated viscera.
;) Figure 7.2 |
7.3. "Symptomatic" hernia
The sudden onset of discomfort or an episode of obstruction should point to the possibility of an associated intra-abdominal lesion, particularly colorectal cancer, an abdominal aortic aneurysm or a bout of ascites. The surgeon must be very attentive when faced with an old groin hernia that until then was well-tolerated, especially in an elderly patient.
;) Figure 7.3 |
1. Introduction
2. Anatomical basics
3. Topological forms
4. Etiology
5. Types/contents
6. Diagnosis
7. Complications
8. References
8.
References
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Nyhus LM. The recurrent groin hernia: therapeutic solutions. World J Surg 1989;13:541-4.
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Nyhus LM, Klein MS, Rogers FB. Inguinal hernia. Curr Probl Surg 1991;28:401-50.