What structures are resected in a Sistrunk procedure and what is the significance of their removal?

Sistrunk Procedure: Structures Resected and Clinical Significance

Structures Resected in the Sistrunk Procedure

The Sistrunk procedure involves en bloc resection of three critical structures: the thyroglossal duct cyst, the central portion of the hyoid bone body (typically 10mm), and a core of tissue extending from the cyst superiorly through the suprahyoid region to the foramen cecum at the base of the tongue. 1, 2, 3

The specific anatomical components removed include:

• The thyroglossal duct cyst itself - the primary pathologic lesion 1
• Central body of the hyoid bone - typically the middle 10mm segment, removed at the junction with the lateral horns 1, 2
• The entire thyroglossal duct tract - the epithelium-lined tract running from the cyst to the foramen cecum 4
• Core of suprahyoid tissue - tissue superior to the hyoid extending to the base of tongue 1, 3

Clinical Significance of Complete Resection

Prevention of Recurrence

Removal of the central hyoid bone and complete duct tract is essential because failure to excise these structures is directly associated with significantly increased recurrence rates. 4

The rationale for this extensive resection is based on embryological principles:

• The thyroglossal duct represents the embryological descent path of the thyroid gland from the foramen cecum to its final cervical position 1
• Epithelial remnants can persist anywhere along this tract, particularly around and through the hyoid bone 4
• Simple cyst excision without hyoid resection results in unacceptably high recurrence rates - studies demonstrate that failure to excise the hyoid bone is a primary risk factor for recurrence 4

Evidence Supporting Complete Resection

The original premise established by Sistrunk remains valid: "the cure of thyroglossal cyst are unsuccessful unless the epithelium-lined tract, running from the cyst to the foramen cecum is completely removed," including the hyoid bone 4

Clinical outcomes data support this approach:

• Recurrence rates are significantly lower (8.8%) with complete Sistrunk procedure compared to simple cyst excision 2
• All recurrences typically occur within 4 months of surgery when incomplete resection is performed 4
• Mean follow-up studies extending 3-5 years show no recurrence when proper technique is employed 1, 2

Additional Clinical Considerations

The hyoid bone must be removed because the thyroglossal duct tract frequently passes through or intimately involves the bone, making it impossible to achieve complete epithelial removal without bone resection 4

Risk factors associated with increased recurrence include:

• Failure to excise the midportion of the hyoid bone and suprahyoid tract 4
• Cyst rupture at the time of operation 4
• Presence of infection 4
• Young patient age (less than 10 years) 4

Critical Anatomical Pitfall

Surgeons must maintain precise orientation to midline cervical anatomy, as the hyoid bone can override the thyroid notch in young children, placing the larynx at risk for catastrophic injury if the thyroid cartilage is mistaken for the hyoid bone. 5

This complication, though rare, results in:

• Significant airway injury requiring urgent laryngotracheoplasty 5
• Tracheotomy requirement with average decannulation time of 4.5 months 5
• Poor voice outcomes in 75% of cases 5

The complete resection of all three components—cyst, central hyoid bone, and suprahyoid tract to foramen cecum—is non-negotiable for achieving cure and preventing recurrence. 1, 4