LOGO
pl en

High-resolution ultrasound of spigelian and groin hernias: a closer look at fascial architecture and aponeurotic passageways

Riccardo Picasso1,2, Federico Pistoia1,2, Federico Zaottini1,2, Sonia Airaldi3, Maribel Miguel Perez4, Michelle Pansecchi1,2, Luca Tovt1,2, Sara Sanguinetti1,2, Ingrid Möller5, Alessandra Bruns6, Carlo Martinoli1,2

Affiliation and address for correspondence
J Ultrason 2021; 21: e53–e62
DOI: 10.15557/JoU.2021.0008
Abstract

From the clinical point of view, a proper diagnosis of spigelian, inguinal and femoral hernias may be relevant for orienting the patient’s management, as these conditions carry a different risk of complications and require specific approaches and treatments. Imaging may play a significant role in the diagnostic work-up of patients with suspected abdominal hernias, as the identification and categorization of these conditions is often unfeasible on clinical ground. Ultrasound imaging is particularly suited for this purpose, owing to its dynamic capabilities, high accuracy, low cost and wide availability. The main limitation of this technique consists of its intrinsic operator dependency, which tends to be higher in difficultto- scan areas such as the groin because of its intrinsic anatomic complexity. An in-depth knowledge of the anatomy of the lower abdominal wall is, therefore, an essential prerequisite to perform a targeted ultrasound examination and discriminate among different types of regional hernias. The aim of this review is to provide a detailed analysis of the fascial architecture and aponeurotic passageways of the abdominal wall through which spigelian, inguinal and femoral hernias extrude, by means of schematic drawings, ultrasound images and video clips. A reasoned landmark-based ultrasound scanning technique is described to allow a prompt and reliable identification of these pathologic conditions.

Keywords
hernia, ultrasound, abdominal wall, groin
Spigelian hernia. Transverse 18–5 MHz ultrasound sweep over the left anterior abdominal wall reveals extrusion of peritoneal fat through a small defect in the Spigelian fascia. After crossing the aponeurotic layers of the transversus abdominis, obliquus internus and obliquus externus, the hernia sac is seen expanding into the subcutaneous tissue. Even if small, the sac is not reducible either spontaneously or applying pressure with the probe due to the small size of the fascial opening. Note the rectus abdominis on the left side of the neck and the fascial planes as they invest the muscle proximal and distal to the fascial defect
Indirect inguinal hernia. Transverse 18–5 MHz ultrasound scan over the internal inguinal ring obtained during Valsalva maneuver. A small occult hernia of peritoneal fat is seen entering the deep inguinal ring. The position of the hernia neck is external to the inferior epigastric vessels. Note that the hernia portal is located external to the rectus abdominis and the inferior epigastric vessels
Direct inguinal hernia. Transverse 18–5 MHz ultrasound scan over Hesselbach’s triangle. During Valsalva, a large-sized hernia is seen expanding between the rectus abdominis muscle and the inferior epigastric vessels through a large defect of the fascia transversalis. Note the displaced vessels on the right side of the field-of-view. The hernia sac contains hyperechoic peritoneal fat and a bowel loop characterized by normal-appearing wall. The hernia appears to be promptly reducible with termination of the Valsalva maneuver
Femoral hernia. Transverse 18–5 MHz ultrasound scan of the femoral canal during Valsalva maneuver. Superficial to the pectineus muscle, a small hernia of peritoneal fat is found protruding through the femoral ring and squeezing the common femoral vein. Note that the femoral artery is completely unaffected by the hernia. The hernia appears fully reducible as soon as the Valsalva maneuver ceases