THE INS AND OUTS OF HERNIAS Cassandra Harrison BA/BSc, MMRU, AMS WHERE TO START? The Clinical Question Essential anatomy Inguinal hernia Scanning technique Variations WHAT IS A HERNIA? CLINICAL INDICATIONS Palpable lump Groin pain Scrotal pain Post operative presentation Neonatal/paediatric presentation THE CLINICAL QUESTION THE INGUINAL CANAL 1
MALE Spermatic cord (veins, arteries, nerves, vas deferens) Ileo-inguinal nerve THE DEEP RING FEMALE Round ligament Ileo-inguinal nerve THE SUPERFICIAL RING Deep Ring TRANSVERSE Inferior Epigastric Vessels NORMAL Superficial Ring Pubic Tubercle TRANSVERSE 2
OPTIMIZATION Linear transducer 5-12 IDENTIFY SUPERFICIAL RING Bowel/Abdomen pre-set Depth Landmark: Pubic Symphysis Transverse plane IDENTIFY DEEP RING Landmark: Inferior Epigastric Vessels Transverse plane INGUINAL CANAL Turn probe 90 degrees Longitudinal plane SCANNING TECHNIQUE THE SCAN Scan along length of canal in transverse at rest and with straining (look for ballooning ) Scan along the canal in longitudinal at rest and with straining (look for sliding ) Vary your transducer pressure (?reducible) Dual screen: document at rest and straining states Cineclips Measure the diameter of the neck of the hernia sac Unilateral vs. Bilateral Erect vs. Supine 3
INDIRECT 75% of inguinal hernias Lateral to the inferior epigastric vessels Slide through the deep ring, along the canal May enter the scrotum More common in younger men Sliding LONGITUDINAL DIRECT 25% of hernias Medial to the inferior epigastric vessels Pop up via defect in posterior wall Usually seen superior to the superficial ring More common in older men Neck Ballooning 4
But I m seeing a direct AND an indirect hernia (I think) Ipsilateral PANTALOON HERNIA (AKA SADDLEBAG HERNIA) Concurrent direct AND indirect hernias Divided by epigastric vessels TRIALS AND TRIBULATIONS Moving target What is normal? Poor patient interaction Large patient Large hernia Post operative scarring or mesh WHAT DOES THE RADIOLOGIST WANT TO KNOW? Is there a hernia? Single vs. Multiple Femoral vs. Inguinal Direct vs. Indirect Contents: Fat vs. Bowel Is it focally tender? Is it reducible? Other pathology HERNIA REDUCIBILITY Reducible (fully, partly) Irreducible Obstructed/Incarcerated 5
REDUCIBLE NON-REDUCIBLE STRANGULATED HERNIA Absence of blood flow within hernia Absence of peristalsis within herniated bowel Usually tender and firm Echogenic fat Free fluid (within the hernia sac or the herniated bowel) Thickened bowel wall (>4mm) Dilated bowel loops within abdomen MESH REPAIR May be difficult to scan Scan above and below Note limitations on worksheet DIFFERENTIALS Femoral hernia Lipoma of the spermatic cord or round ligament Athletic Pubalgia Appendix Ovarian pathology Abscess Varicocele/Hydrocele Neurofibroma Haematoma Abscess Varicocele/Hydrocele Metastasis FEMORAL HERNIA VARIATIONS More common in females than males Femoral vessels: posterior and inferior to inguinal ligament Medial to the femoral vein Compresses the femoral vein on deep Valsalva (preventing augmentation) Passes below and lateral to the pelvic tubercle vs an inguinal hernia which will be seen above and medial to the pelvic tubercle. 6
SPIGELIAN HERNIA Uncommon (approx., 0.1% of abdominal wall hernias AT REST VALSALVA Congenital vs. Acquired (perforator, stretching, scarring) Usually passes through transverse abdominis and internal oblique aponeuroses Will spread out beneath the intact aponeurosis of the external oblique, or, lie in the rectus sheath beside the rectus. 7
ABDOMINAL WALL HERNIA UMBILICAL HERNIA INCISIONAL HERNIA Site of previous surgery (usually bowel or gynae) Up to 30% of major abdominal surgery will result in an incisional hernia Obese patients at increased risk Multiple surgeries increase risk Usually presents 3-6 months post surgery DIVARIFICATION (Diastasis Recti Abdominis) Linear Alba intact Visible midline bulge on abdominal tension Not a true hernia (peritoneal cavity does not pass through the Linea Alba) Separation of the left and right rectus muscles Intact but widened Linea Alba Separation >2.0cm 8
TIPS AND TRICKS Learn your landmarks Familiarize yourself with normal There are many ways to strain Hernia is best seen just after straining Heel-toe If normal: scan erect Scan the contralateral side if a hernia is found REFERENCES Biasutto SN et al. 2009, Inguinal canal development: the muscular wall and the role of the gubernaculum, Clin Anat, vol. 22, no. 5, pp. 614-618 Desai PK 2009, Infected Mesh. [ONLINE] Available at: https://radiopaedia.org/cases/infected-mesh-1. [Accessed 25 June 2017]. Jacobson JA, Khoury V & Brandon CJ 2015, Ultrasound of the Groin: Techniques, Pathology, and Pitfalls, AJR vol. 205, pp. 513-523 Jenkins JT & O Dwyer PJ 2008, Inguinal hernias, British Medical Journal, vol. 336, no. 7638, pp. 269 272 Kulacoglu H 2011, Current options in inguinal hernia repair in adult patients, Hippokratia, vol. 15, no. 3, pp. 223-231 Miller PA, Mezwa DG, Feczko PJ et al. 1995, Imaging of abdominal hernias, Radiographics, vol.15, no. 2, pp. 333-47 Smereczyński A et al. 2012, Sonographic imaging of Spigelian hernias, Journal of Ultrasonography, vol. 12, no. 50, pp. 269-275. Ultrasoundpaedia. 2014. Ultrasound of the hip & groin - Normal. [ONLINE] Available at: http://www.ultrasoundpaedia.com/normal-hip-groin/. [Accessed 23 June 2017]. Volkan et al. 2011, Prevalence of diastasis recti abdominis in the population of young multiparous adults in Turkey, Ginekol Pol., vol. 82, pp. 817-821 Yoong P, Duffy S & Marshall TJ 2013, The inguinal and femoral canals: A practical step-by-step approach to accurate sonographic assessment, The Indian Journal of Radiology & Imaging, vol. 23, no. 4, pp. 391 395 9