Extended End-to-End Anastomosis via Left Thoracotomy #2: End-to-End Anastomosis

1. Operative Objective

Extended end-to-end anastomosis is designed to relieve coarctation of the aorta by completely removing the obstructive and ductal tissue and constructing a broad, tension-free connection between the distal aortic arch and descending thoracic aorta.

The procedure differs conceptually from a limited coarctectomy followed by a short circumferential end-to-end anastomosis. In extended repair, the proximal incision is deliberately carried along the undersurface of the distal aortic arch, while a corresponding longitudinal counterincision is created in the descending aorta. These maneuvers transform two relatively small aortic openings into a long oblique anastomotic surface.

The fundamental objectives are:

1. Complete removal of coarctation and ductal tissue.
2. Adequate mobilization of the distal arch and descending aorta.
3. Extension of the reconstruction beyond the anatomically narrow isthmus.
4. Creation of the largest practical native-tissue anastomotic surface.
5. Avoidance of tension, rotation, kinking, or purse-string narrowing.
6. Restoration of a smooth transition from the transverse arch into the descending thoracic aorta.

These principles are important because recurrent obstruction is not simply a problem of the suture line. Residual ductal tissue, unaddressed arch hypoplasia, inadequate mobilization, and unfavorable reconstructed geometry can all contribute to recoarctation.

2. Proximal and Distal Aortic Control

After complete exposure and mobilization of the distal arch, isthmus, ductus arteriosus, and proximal descending thoracic aorta, vascular clamps are applied to isolate the segment requiring reconstruction.

The distal clamp is placed on the descending aorta beyond the coarctation. The proximal clamp is positioned across the distal arch according to the individual anatomy and the extent of arch hypoplasia. Sufficient proximal aortic length must remain accessible to permit extension of the incision along the undersurface of the arch.

Several principles guide clamp placement:

• The clamp should not distort the intended anastomotic margin.
• Adequate descending aortic length must remain available for tension-free approximation.
• The proximal clamp should permit the reconstruction to extend into healthy, adequately sized arch tissue.
• Unnecessary traction on the distal arch and ductal region should be avoided.
• All mobilization and operative planning should be completed before clamping to minimize ischemic time to the lower body.

For isolated coarctation repair through a left thoracotomy, cardiopulmonary bypass is generally unnecessary. Proximal systemic and cerebral perfusion continue while flow to the descending thoracic aorta is temporarily interrupted during reconstruction.

3. Ductus Arteriosus Ligation and Division

A patent ductus arteriosus is securely controlled and ligated before division. Division of the ductus separates the pulmonary artery from the juxtaductal aorta and improves mobility of the aortic isthmus.

This step is more than an exposure maneuver. Histologic evaluation of resected coarctation specimens has demonstrated that ductal tissue may extend into the wall of the adjacent juxtaductal aorta [1]. Contraction and subsequent fibrosis of retained ductal tissue provide a plausible substrate for secondary narrowing after apparently adequate repair.

Consequently, the operative goal is not simply division of the ductus. The abnormal ductal component incorporated into the aortic wall should be removed together with the coarctation segment.

Careful dissection is required around the ductal region because of the proximity of the left recurrent laryngeal nerve. Excessive traction, thermal injury, and unnecessarily deep dissection around the pulmonary artery should be avoided.

4. Complete Coarctectomy and Removal of Ductal Tissue

Following proximal and distal clamping and ductal division, the coarcted segment is excised.

The resection should encompass:

• the macroscopically narrowed aortic segment,
• the coarctation shelf or ridge,
• the ductal insertion,
• and residual abnormal or thickened ductal tissue at both aortic ends.

After excision, both cut surfaces should be inspected carefully. The remaining margins should consist of supple native aortic tissue suitable for incorporation into the reconstruction.

The concept of removing the entire abnormal juxtaductal segment is supported by surgical series in which extensive resection was combined with anastomosis of the descending aorta to the undersurface of the arch. Rajasinghe and colleagues specifically emphasized removal of potentially abnormal ductal and hypoplastic tissue as a means of reducing recurrent obstruction; no surviving patient in their neonatal and young-infant cohort required reintervention during follow-up [2].

The balance is important. Inadequate resection leaves an obstructive substrate, whereas excessive shortening of the proximal and distal aorta may increase anastomotic tension. The objective is therefore complete resection of abnormal tissue while preserving sufficient healthy aortic length for reconstruction.

5. Extended Incision Along the Undersurface of the Aortic Arch

After coarctectomy, the proximal opening is enlarged by extending the incision longitudinally along the undersurface of the distal aortic arch.

This maneuver distinguishes extended end-to-end repair from a conventional short end-to-end anastomosis.

A simple transverse division at the isthmus leaves the size of the proximal anastomosis dependent on the diameter of the distal arch. This may be inadequate in neonates and infants with associated distal arch hypoplasia. By extending the proximal incision toward a larger segment of the transverse arch, the surgeon creates a substantially longer anastomotic margin.

The degree of proximal extension should therefore be individualized according to arch anatomy. The incision should extend sufficiently proximal to the narrow segment while avoiding injury to the origins of the arch branches.

The purpose is not merely to enlarge the opening. The descending aorta is ultimately incorporated into the undersurface of the arch, allowing native descending aortic tissue to augment the hypoplastic distal arch and create a smoother transition between the transverse arch and descending thoracic aorta.

6. Longitudinal Counterincision in the Descending Aorta

A corresponding longitudinal counterincision is created in the proximal descending thoracic aorta.

This incision converts the circular distal opening into a longer anastomotic surface that can be matched to the extended arch incision. The length and orientation should be selected so that the descending aorta approaches the arch naturally without rotation.

The combination of the proximal arch extension and distal counterincision creates a long oblique anastomosis. Geometrically, this increases the effective anastomotic area and reduces dependence on the original diameter of the narrowed isthmus.

The counterincision should not be excessively short, which may leave a restricted reconstruction, or unnecessarily long, which can complicate alignment. The surgeon should tailor both incisions to one another rather than relying on a predetermined incision length.

7. Mobilization and Aortic Approximation

Before beginning the anastomosis, the descending aorta is brought toward the distal arch to confirm that the two structures approximate without significant tension.

This is a critical assessment.

The surgeon should evaluate:

• whether the descending aorta reaches the arch easily,
• whether further mobilization is required,
• whether the descending aorta rotates during approximation,
• whether the posterior walls align naturally,
• and whether the reconstructed aorta will follow a smooth curve.

If substantial force is required to bring the aortic ends together, additional mobilization should be performed before suturing. A technically precise anastomosis constructed under excessive longitudinal tension remains an unfavorable reconstruction.

Extensive mobilization was an important component of early extended-resection strategies [1,2]. The principle remains particularly relevant in neonates and young infants, in whom the repaired segment must accommodate subsequent somatic growth.

At the same time, mobilization must remain controlled. Excessive circumferential dissection may injure intercostal branches, lymphatic structures, or adjacent nerves.

8. Posterior Wall Anastomosis

The anastomosis is generally begun at the deepest portion of the field, reconstructing the posterior wall first.

A fine monofilament vascular suture is typically used in a running fashion. Suture size depends on patient size and institutional practice.

Accurate posterior-wall alignment is critical because rotational error may become difficult to recognize after completion of the anterior wall. The initial sutures establish the relationship between the extended arch incision and the descending aortic counterincision.

Important technical principles include:

• consistent spacing between sutures,
• symmetric tissue bites,
• appropriate distance from the cut edge,
• precise intima-to-intima approximation,
• avoidance of tissue inversion,
• and controlled suture tension.

The running suture should approximate rather than constrict the aortic wall. Excessive tension can create a purse-string effect and reduce the functional diameter of an otherwise adequately extended reconstruction.

As the posterior wall is constructed, the descending aorta becomes incorporated progressively into the undersurface of the distal arch.

9. Completion of the Long Oblique Anastomosis

After the posterior wall is completed, the running suture is continued around the remaining circumference of the reconstruction.

The resulting suture line is long and oblique rather than short and circumferential. This configuration offers several theoretical and practical advantages:

• increased anastomotic area,
• augmentation of the distal arch using native tissue,
• reduced focal narrowing at the original isthmus,
• distribution of tension over a longer suture line,
• and correction of associated distal arch hypoplasia.

Before the final sutures are secured, the surgeon should inspect the lumen and ensure that the reconstructed aorta is not twisted. The aortic ends may be flushed according to institutional practice before complete closure.

The finished reconstruction should demonstrate a smooth transition from the distal arch into the descending thoracic aorta without an obvious waist or acute angulation.

10. Restoration of Aortic Flow

After completion of the anastomosis, the vascular clamps are released in a controlled fashion.

The repair is inspected immediately for:

• anastomotic bleeding,
• residual narrowing,
• excessive tension,
• distortion of the distal arch,
• kinking of the descending aorta,
• and adequate distal pulsatility.

Lower-extremity perfusion should be reassessed by direct palpation, Doppler examination, and comparison of upper- and lower-extremity arterial pressures when available.

An early pressure gradient should not be interpreted in isolation. Systemic vascular resistance, ventricular function, arterial line location, and postoperative loading conditions can influence measured gradients. Direct operative geometry and postoperative echocardiographic assessment remain important components of evaluating repair adequacy.

11. Evidence for Durability of Extended End-to-End Repair

Clinical series support the durability of extended resection and extended end-to-end reconstruction in neonates and infants.

Backer and colleagues reported recoarctation in only 2 of 55 infants undergoing resection with extended end-to-end anastomosis, corresponding to a 3.6% recoarctation rate [3]. Wright and colleagues subsequently reported a 6% reintervention rate after an extended end-to-end strategy designed to enlarge areas of associated arch hypoplasia [4].

A series of 124 neonates and infants repaired through left thoracotomy reported recurrent arch obstruction in 8%, typically developing during infancy; balloon angioplasty was effective for recurrent obstruction in that cohort [5]. In a larger long-term series using resection and extended end-to-end anastomosis through left thoracotomy, only 2% of 251 patients required reintervention, demonstrating durable relief of obstruction over extended follow-up [6].

Taken together, these series demonstrate recurrent obstruction or reintervention rates of approximately 2–8%, although comparison between studies must account for differences in patient age, arch anatomy, associated lesions, operative technique, definitions of recoarctation, and duration of follow-up [3-6].

These results support the central technical concept that complete removal of abnormal tissue combined with a broad native-tissue reconstruction can provide durable relief of coarctation.

12. Distal and Transverse Arch Hypoplasia

The anatomy proximal to the discrete coarctation remains a major determinant of outcome.

A technically wide anastomosis does not fully correct obstruction if substantial transverse arch hypoplasia remains proximal to the reconstruction. In the long-term left-thoracotomy series, transverse arch hypoplasia was associated with increased risk of reintervention [6].

Operative approach should therefore be selected according to the distribution of arch hypoplasia rather than the appearance of the juxtaductal coarctation alone.

Tulzer and colleagues reported excellent overall outcomes after arch reconstruction, with approximately 90% freedom from reintervention at 10 years, but identified lateral thoracotomy as a risk factor for recurrent obstruction in their cohort [7]. This finding should not be interpreted as evidence that thoracotomy itself produces recoarctation. Rather, it emphasizes that patients with more extensive proximal arch hypoplasia may require reconstruction beyond the territory that can be optimally addressed through a standard lateral approach.

Thus, extended end-to-end repair through thoracotomy is particularly suitable when the hypoplastic segment can be effectively incorporated into the extended native-tissue anastomosis. More extensive proximal transverse arch disease may favor reconstruction through median sternotomy.

13. Technical Pitfalls and Procedure-Related Complications

Incomplete ductal tissue removal

Residual ductal tissue may participate in secondary constriction. Both proximal and distal margins should therefore be inspected after coarctectomy [1,2].

Inadequate proximal extension

An anastomosis may be technically wide yet remain functionally obstructive if it terminates in a significantly hypoplastic distal arch.

Inadequate mobilization

Failure to mobilize the descending aorta sufficiently creates excessive longitudinal tension and may contribute to narrowing or distortion.

Rotational malalignment

The descending aorta may rotate as it is brought toward the arch. Failure to recognize this can produce a spiral configuration or postoperative kink.

Excessive running-suture tension

A running suture under excessive tension can generate circumferential narrowing despite an adequately sized incision.

Recurrent laryngeal nerve injury

The left recurrent laryngeal nerve is vulnerable during dissection around the ductal region. Postoperative vocal cord dysfunction may manifest as weak cry, hoarseness, aspiration, or feeding difficulty.

Chylothorax and adjacent-structure injury

Lymphatic structures can be injured during extensive descending aortic mobilization. Chylothorax and recurrent laryngeal nerve dysfunction have been reported but remain uncommon after thoracotomy repair; major neurologic complications such as paraplegia are exceptionally rare in contemporary series [4].

14. Final Surgical Concept

Extended end-to-end repair should be understood as geometric reconstruction of the distal aortic arch, not simply removal of a discrete coarctation.

The operative sequence can be summarized as:

Clamp → divide the ductus → completely remove the coarctation and ductal tissue → extend the incision along the undersurface of the arch → create a longitudinal descending aortic counterincision → mobilize and approximate without tension → construct the posterior wall → complete the long oblique anastomosis → restore flow and assess the reconstruction.

Durable repair depends on the interaction of four principles:

complete resection + adequate mobilization + sufficient arch extension + tension-free anastomotic geometry.

When these principles are achieved, the descending aorta becomes incorporated into the undersurface of the distal arch, replacing the narrowed juxtaductal segment with a broad native-tissue pathway. Contemporary series demonstrate low recurrent obstruction and reintervention rates, while also emphasizing that the extent of transverse arch hypoplasia must remain central to operative planning [3-7].

References

[1] Son JA, Falk V, Schneider P, Smedts F, Mohr FW. Repair of coarctation of the aorta in neonates and young infants. J Card Surg. 1997. doi:10.1111/j.1540-8191.1997.tb00114.x.

[2] Rajasinghe HA, Reddy VM, van Son JAM, Black MD, McElhinney DB, Brook MM, Hanley FL. Coarctation repair using end-to-side anastomosis of descending aorta to proximal aortic arch. Ann Thorac Surg. 1996. doi:10.1016/0003-4975(95)01153-6.

[3] Backer CL, Mavroudis C, Zias EA, Amin Z, Weigel TJ. Repair of coarctation with resection and extended end-to-end anastomosis. Ann Thorac Surg. 1998. doi:10.1016/S0003-4975(98)00671-7.

[4] Wright GE, Nowak CA, Goldberg CS, Ohye RG, Bove EL, Rocchini AP. Extended resection and end-to-end anastomosis for aortic coarctation in infants: results of a tailored surgical approach. Ann Thorac Surg. 2005. doi:10.1016/j.athoracsur.2005.04.002.

[5] Belyaeva MM, Ilyin VN, Kornouhov OY, Kornouhov YY, Kalinina OI. Coarctation repair through left thoracotomy in neonates and infants. Patologiya krovoobrashcheniya i kardiokhirurgiya. 2018;4:12-20. doi:10.21688/1681-3472-2018-4-12-20.

[6] Gropler MR, Marino BS, Carr MR, Russell WW, Gu H, Eltayeb OM, Monge MC, Backer CL. Long-term outcomes of coarctation repair through left thoracotomy. Ann Thorac Surg. 2019. doi:10.1016/j.athoracsur.2018.07.027.

[7] Tulzer A, Mair R, Kreuzer M, Tulzer G. Outcome of aortic arch reconstruction in infants with coarctation: importance of operative approach. J Thorac Cardiovasc Surg. 2016. doi:10.1016/j.jtcvs.2016.08.029.