RAA with Aberrant LSCA from Kommerell’s Diverticulum #2: Surgical Technique
Right aortic arch with an aberrant left subclavian artery arising from Kommerell’s diverticulum is one of the classic anatomic substrates of a complete vascular ring. The airway and esophagus are compressed not only by the circular configuration of the ring, but also by the posterior retroesophageal course of the aberrant left subclavian artery and the bulging diverticular origin at the descending thoracic aorta.
Therefore, the modern surgical concept has shifted from simple division of the ligamentum arteriosum alone toward a more complete anatomic repair in selected patients: division of the ligamentum arteriosum, resection of Kommerell’s diverticulum, closure of the aortic stump, and reimplantation or translocation of the left subclavian artery to the left common carotid artery [1–4].
1. Surgical Objective
The objective of surgery is not merely to open the vascular ring, but to eliminate all clinically relevant sources of tracheoesophageal compression.
1.1 Release of the circular ring
The left ligamentum arteriosum completes the vascular ring between the pulmonary artery and the descending aortic/Kommerell region. Division of this structure releases the circumferential constriction around the trachea and esophagus.
1.2 Elimination of posterior compression
Kommerell’s diverticulum may behave as a posterior pulsatile mass. Even after ligamentum division, the residual diverticulum can remain behind the esophagus and trachea, producing persistent or recurrent respiratory and swallowing symptoms [1, 2].
1.3 Removal of the retroesophageal vascular sling
The aberrant LSCA courses posterior to the esophagus. Reimplantation into the left common carotid artery removes this retroesophageal course while preserving antegrade perfusion to the left upper extremity and vertebral circulation [2, 3].
2. Operative Strategy: “Release, Resect, Reconstruct”
The operation can be summarized in three surgical principles:
- Release
- Resect
- Reconstruct
Divide the ligamentum arteriosum to open the vascular ring.
Remove Kommerell’s diverticulum at its base to eliminate residual posterior compression and avoid leaving a diverticular stump.
Reimplant or translocate the LSCA to the left common carotid artery to preserve arterial flow and eliminate the retroesophageal sling.
This strategy aims to create a durable decompression of the airway and esophagus, rather than a partial release of the ring alone.
3. Technical Sequence
3.1 Exposure
The operation is commonly performed through a left thoracotomy, although the approach may vary depending on patient size, associated intracardiac lesions, and institutional strategy. The operative field should clearly identify:
- Descending thoracic aorta
- Kommerell’s diverticulum
- Aberrant LSCA
- Left common carotid artery
- Ligamentum arteriosum
- Esophagus
- Recurrent laryngeal nerve region
- Thoracic duct region
Preoperative CT angiography is critical for understanding the relationship among the arch, diverticulum, airway, esophagus, and head-and-neck vessels.
3.2 Division of the ligamentum arteriosum
The ligamentum arteriosum is identified and divided completely. This step immediately opens the circular component of the ring. Both ends should be securely controlled because the ligamentum may be short, thickened, or closely associated with the diverticular origin.
3.3 Mobilization of the aberrant LSCA
The aberrant LSCA is mobilized sufficiently to allow tension-free translocation. The surgeon must balance two competing needs:
- Adequate mobilization for a smooth carotid–subclavian anastomosis
- Avoidance of excessive skeletonization that may injure adjacent neural, lymphatic, or vascular structures
The final course of the LSCA should be straight, non-kinked, and free of rotational tension.
3.4 Resection of Kommerell’s diverticulum
Kommerell’s diverticulum is controlled at its aortic base. A partial occlusion clamp may be used depending on anatomy and exposure. The diverticulum is then resected, and the aortic stump is oversewn.
Important technical points include:
- Avoid leaving a residual posterior pouch.
- Avoid narrowing or distortion of the descending thoracic aorta.
- Ensure hemostatic closure of the aortic wall.
- Confirm that the residual aortic contour no longer compresses the esophagus or airway.
Histologic studies have shown medial abnormalities, including cystic medial degeneration, in a substantial proportion of resected diverticula, supporting resection not only for decompression but also for concern regarding future aneurysmal behavior [3].
3.5 LSCA reimplantation into the left common carotid artery
The LSCA is reimplanted into the left common carotid artery in an end-to-side fashion. The anastomosis should be:
- Wide
- Tension-free
- Non-twisted
- Non-kinked
- Oriented to maintain unobstructed flow to the left arm and vertebral circulation
This step converts the LSCA from a posterior retroesophageal vessel into an anterior cervical branch, removing its compressive course while maintaining physiologic perfusion.
4. Why Ligamentum-Only Division May Be Incomplete
Historically, simple division of the ligamentum arteriosum was often considered sufficient. However, several pediatric series have demonstrated that this strategy may leave behind two important residual problems:
- Persistent posterior compression by Kommerell’s diverticulum
- Persistent retroesophageal tethering by the aberrant LSCA
Backer and colleagues described children with recurrent respiratory symptoms or dysphagia after prior vascular ring division in whom the untreated Kommerell diverticulum was identified as an independent cause of residual compression. Reoperation with diverticulum resection and LSCA transfer resulted in symptom improvement [1].
Shinkawa and colleagues compared ligamentum division alone with primary LSCA translocation and diverticulum removal. Their results supported primary translocation as a safe and effective strategy, with fewer persistent respiratory-medication requirements after complete repair [2].
Luciano and colleagues further emphasized that Kommerell diverticulum should be removed in children with vascular ring and aberrant LSCA, citing both symptom relief and histologic abnormalities of the diverticular wall [3].
5. Contemporary Evidence and Nuanced Interpretation
The current literature generally supports complete anatomic repair in symptomatic children, especially when the diverticulum is prominent or the LSCA has a clear retroesophageal compressive course. Large contemporary pediatric data have shown excellent symptom resolution and high anastomotic patency after early diverticulum resection and revascularization [6].
However, the literature is not entirely uniform. A recent 21-year comparative analysis reported that Kommerell diverticulum resection with arterial translocation was safe and effective, but long-term symptom recurrence was not significantly different from simpler surgical strategies in selected patients [7]. Similarly, plication and pexy of the diverticulum with ligamentum division has been reported as an effective alternative to formal diverticulum resection and LSCA reimplantation in selected pediatric patients [8].
Thus, the surgical decision should be individualized. The key issue is not whether every patient requires the most extensive operation, but whether the chosen operation adequately addresses the patient’s specific anatomy and mechanism of compression.
6. Surgical Pearls
- Do not treat the ligamentum as the only problem.
- Resect or remodel the diverticular component when it is clinically relevant.
- Preserve LSCA perfusion whenever possible.
- A tension-free carotid–subclavian anastomosis is essential.
- The operation is three-dimensional decompression.
The ligamentum completes the ring, but Kommerell’s diverticulum and the retroesophageal LSCA may be the dominant residual compressive structures.
A residual diverticular pouch may continue to compress the esophagus or airway.
Reimplantation avoids left arm ischemia, vertebrobasilar flow concerns, and potential subclavian steal physiology.
Inadequate mobilization may cause kinking, stenosis, or compromised left upper-extremity perfusion.
The surgeon must convert a posterior retroesophageal vascular configuration into a non-compressive anterior cervical branch pattern.
7. Textbook Summary
Surgical repair of right aortic arch with aberrant LSCA arising from Kommerell’s diverticulum should be conceptualized as complete anatomic decompression rather than simple vascular ring division. The ligamentum arteriosum is divided to release the circular ring, Kommerell’s diverticulum is resected or remodeled to eliminate posterior tracheoesophageal compression, and the LSCA is reimplanted into the left common carotid artery to remove the retroesophageal vascular sling while preserving left upper-extremity perfusion. Current evidence supports this comprehensive approach in symptomatic children and in patients with a significant diverticular component, while alternative strategies such as diverticulum plication/pexy may be reasonable in selected anatomies.
References
[1] Backer CL, Hillman N, Mavroudis C, Holinger LD. Resection of Kommerell's diverticulum and left subclavian artery transfer for recurrent symptoms after vascular ring division. Eur J Cardiothorac Surg. 2002;22(1):64-69.
[2] Shinkawa T, Greenberg SB, Jaquiss RDB, Imamura M. Primary translocation of aberrant left subclavian artery for children with symptomatic vascular ring. Ann Thorac Surg. 2012;93(4):1262-1265.
[3] Luciano D, Mitchell J, Fraisse A, Lepidi H, Kreitmann B, Ovaert C. Kommerell diverticulum should be removed in children with vascular ring and aberrant left subclavian artery. Ann Thorac Surg. 2015;100(6):2293-2297.
[4] Backer CL, Russell HM, Wurlitzer KC, Rastatter JC, Rigsby CK. Primary resection of Kommerell diverticulum and left subclavian artery transfer. Ann Thorac Surg. 2012;94(5):1612-1617.
[5] An K, Li S, Yan J, Wang X, Hua Z. Translocation of aberrant left subclavian artery and resection of Kommerell diverticulum during the concomitant repair of intracardiac anomalies. Interact Cardiovasc Thorac Surg. 2021;32(1):118-124.
[6] Du XW, Wang H, Chen LQ, Zhang DW, Xu ZW, Lu ZH, Wang SM, Zhang HB. Early resection of Kommerell diverticulum and revascularization in children with right aortic arch and aberrant left subclavian artery. Ann Thorac Surg. 2025;120(5):1144-1153.
[7] Marsh JC, Muralidaran A, Shen I, Iguidbashian JP, Ootaki Y. The impact of Kommerell diverticulum resection on patient outcomes: A 21-year comparative analysis of surgical techniques for vascular rings. JTCVS Open. 2025;28:428-433.
[8] Perkins AA, Tomescu AL, Knott-Craig CJ, Boston U, Spentzas T, Ramakrishnan KV. Aortopexy with plication of Kommerell diverticulum is an effective alternative to diverticulum resection and reimplantation of the aberrant left subclavian artery for surgical management of vascular rings in children. World J Pediatr Congenit Heart Surg. 2025;16(4):446-449.