Simultaneous single-staged surgical management of coarctation of aorta concomitant with intra-cardiac abnormality by extra-anatomic aortic bypass grafting

Introduction

Coarctation of the aorta (CoA), a congenital defect if not corrected surgically primarily in childhood, usually goes undiagnosed until adulthood and is diagnosed usually during evaluation for systemic hypertension, as it is the most common presentation. ¹ Association of coarctation of aorta with other cardiac abnormalities such as bicuspid aortic valve, congenital abnormalities and mitral valve pathologies is common. ² Surgical management of coarctation of aorta with associated cardiac abnormalities is challenging. While some prefer simultaneous repair of both coarctation and associated abnormalities, others prefer a two-staged repair. ³ Also, some prefer separate incisions for repair of both (median sternotomy and left anterior thoracotomy) either simultaneous or staged, whereas some prefer single incision (median sternotomy). Lack of consensus on concomitant repair of both due to lack of data and relatively a small number of patients on one side and a large variety of complications on the other. ⁴ In this retrospective study, we describe our experience in 17 adults who underwent simultaneous repair of coarctation of aorta and associated cardiac abnormalities via extra-anatomic bypass using median sternotomy.

Materials and methods

It was a retrospective study. All the patients who were adults and diagnosed to have coarctation of aorta along with concomitant intracardiac abnormalities were included in the study. Exclusion criteria included patients who were less than 18 years of age or had isolated coarctation of aorta. The study included patients who underwent simultaneous repair of coarctation and intra-cardiac abnormalities.

All the patients in the study were taken up for surgery after routine pre-operative workup, written and informed consent. After systemic heparinisation, dual arterial cannulation was done (right axillary and left femoral artery) to maintain perfusion to both upper and lower half of the body. Median sternotomy and bicaval cannulation were done. Cardiopulmonary bypass (CPB) was established. Aorta was cross clamped, and antegrade root or ostial cardioplegia (in cases of aortic insufficiency and type A aortic dissection) was given. Heart was arrested in diastole. Heart was retracted, and posterior pericardium over the descending thoracic aorta (DTA) was exposed via a longitudinal incision. Descending thoracic aorta was partially clamped. The distal anastomosis of extra-anatomic bypass on DTA was performed using either polytetrafluoroethylene or polyester/Dacron graft (14 mm or 16 mm) (end to side). The graft was then passed behind inferior vena cava (IVC) inferior to the right inferior pulmonary vein and then brought lateral to the right atrium. The associated cardiac abnormalities were addressed. Aortic cross clamp was released after deairing. The proximal anastomosis of extra-anatomic bypass was performed under partial clamping of the ascending aorta. Patient was weaned off CPB. Figure 1 shows the intraoperative image of a patient who underwent a concomitant ascending-to-descending thoracic aortic bypass with Bentall procedure for coarctation of aorta with aortic root aneurysm with aortic insufficiency.

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Figure 1.

Intra operative image showing extra-anatomic bypass repair with Bentall procedure after complete repair.

The endpoints of this study were perioperative death and major cardiovascular events. Statistical analysis was performed using fundamental statistics methods using Microsoft Excel^® (Microsoft Inc., Washington, USA).

Results

A total of 17 adult patients underwent simultaneous repair of coarctation and concomitant cardiac abnormalities between January 2014 and December 2023.

Pre-operative data

Ten were males (58.8%) and seven (41.2%) were females. The mean age of our patients was 35.94 ± 12.70 years. All the patients were diagnosed with systemic hypertension and the mean gradient in the upper and lower limb blood pressure (BP) was 49.71 ± 7.35 mmHg. Two out of 17 patients (11.75%) were in New York Heart Association (NYHA) functional class I, 13 out of 17 (76.5%) in NYHA class II and 2 out of 17 (in %) NYHA class III. Two dimensional-echocardiography was done in all patients to diagnose associated intra-cardiac abnormality. Chest X-ray and contrast-enhanced computed tomography (CT) aortogram were also done to confirm diagnosis of coarctation of aorta. The mean shortest diameter of the coarctation segment was 9.18 ± 2.32 mm on CT aortogram. Figure 2A shows preoperative CT aortogram of one of our patients with coarctation of aorta and associated aortic root aneurysm.

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Figure 2.

(A) Pre-operative image showing coarctation of aorta with aortic root aneurysm. (B) Post-operative CT aortogram showing well-flowing ascending to descending aorta graft with aortic valved conduit graft.

Associated cardiac diseases and concomitant procedures:

The associated intra-cardiac abnormalities included aortic insufficiency (7), bicuspid aortic valve (7), aortic aneurysm (6), aortic stenosis (4), type A aortic dissection (3), sub-aortic membrane (1), mitral valve prolapse causing insufficiency (1), mitral valve insufficiency (1), coronary artery disease (1), right ventricular outflow tract (RVOT) obstruction (1), atrial septal defect (ASD) (1) and ventricular septal defect (VSD) (1).

The preoperative diagnosis of coarctation of aorta in our study was based on gradient between upper limb and lower limb BP and CT aortogram. A peak gradient of more than 20 mmHg and also a reduction in the diameter at the level of isthmus of aorta greater than 50% was considered as severe coarctation of aorta. Table 1 describes preoperative diagnosis, surgery performed and immediate complications. Table 2 shows operative data and postoperative outcomes.

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Table 1.

Preoperative diagnosis, surgery performed and immediate complications.

Patient no.	Age	Pre op diagnosis	Concomitant procedure with ascending-to-descending bypass	Immediate complications	BP gradient between upper limb and lower limbBP Pre-op vs. Post-op (mmHg)
1.	18 years	CoA, dilated aortic root with aneurysm, bicuspid aortic valve, severe AR	Bentall procedure	None	44 vs 14
2.	28 years	CoA, mitral valve prolapse, severe MR, bicuspid aortic valve, moderate AR	Double valve replacement (AVR + MVR)	None	54 vs 10
3.	60 years	CoA, severe AS, aneurysmal outpouching of noncoronary sinus	AVR	None	50 vs 8
4.	46 years 4 months	CoA, aortic root aneurysm, severe AR	Bentall procedure	None	58 vs 20
5.	29 years 7 months	CoA, bicupsid aortic valve, severe AS	AVR	None	62 vs 28
6.	21 years 8 months	CoA, SAM, severe AS	AVR, SAM resection	None	70 vs 22
7.	46 years 5 months	CoA, ascending aortic aneurysm	Bentall procedure	Mortality	54 vs 30
8.	43 years 10 months	CoA, aortic root aneurysm, severe AR	Aortic aneurysm repair	None	78 vs 34
9.	26 years 9 months	CoA, RVOT stenosis	RVOT resection	None	52 vs 10
10.	18 years 10 months	CoA, perimembranous VSD	VSD closure	None	60 vs 24
11.	37 years 9 months	CoA, stanford type A dissection, bicuspid aortic valve, severe AR	Bentall procedure	None	52 vs 26
12.	32 years 11 months	CoA, aortic root aneurysm, bicuspid aortic valve, severe AR	Bentall procedure	None	60 vs 28
13.	31 years 11 months	CoA, severe MR	Mitral valve replacement	None	60 vs 12
14.	45 years 6 months	CoA, bicuspid aortic valve, severe AS	Aortic valve replacement	None	44 vs 10
15.	31 years 3 months	CoA, ostium secundum atrial septal defect	Atrial septal defect closure	None	42 vs 8
16.	58 years 9 months	CoA, aortic root aneurysm, bicuspid aortic valve, severe AR,	Bentall procedure	None	62 vs 8
17.	42 years 9 months	CoA, coronary artery disease	CABG	None	42 vs 10

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Table 2.

Operative data and postoperative outcomes.

Mean narrowest coarctation diameter	9.18 ± 2.32 mm
CPB time	198.82 ± 52 min
Aortic cross-clamp time	149 ± 51.47 min
Ventilation time	18 ± 15.60 h
ICU stay	3.94 ± 0.83 days
Hospital stay	6.76 ± 1.68 days
Mean gradient in BP pre-operatively	49.71 ±7.35 mmHg
Mean gradient in BP post-operatively (immediate)	11.18 ± 3.94 mmHg
Left ventricular ejection fraction on last follow-up echocardiography	52.86 ± 5.46%

The concomitant intracardiac procedures involved aortic valve replacement (5), Bentall procedure (5), ascending aortic replacement (1), mitral valve replacement in (2), sub-aortic membrane excision (1), RVOT widening (1), coronary artery bypass grafting (1), ASD closure (1) and VSD closure (1) (Table 3).

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Table 3.

Concomitant procedures.

Aortic valve replacement	5
Bentall procedure	5
Ascending aortic replacement	1
Mitral valve replacement	2
Repair of congenital defect (ASD/VSD/SAM excision/ RVOT resection)	4
Coronary artery bypass grafting	1

Chest was kept open in 13 of our patients electively in view of bleeding, which was closed next day (where there was bleeding from the needle holes or bleeding was due to medical cause/due to coagulopathy).

Discussion

Coarctation of the aorta is one of the commonest congenital cardiovascular anomalies with an incidence rate of 6.45%. ⁵ However, its association with other intracardiac anomalies is rare and is reported to be seen in <1% patients. ⁶ Additionally, abnormalities of aortic media can also be seen with CoA which become more significant as the patient's age increases and later developing into aortic aneurysms. In adults, complex CoA are also seen to be associated with acquired malformations such as coronary artery disease, aortic valve disease, mitral valve disease and subvalvular aortic stenosis. ⁵

Currently, there is no universally accepted approach for the optimal management of complex CoA when it is associated with concomitant intracardiac abnormalities. The primary treatment strategies for CoA include either the classical anatomic repair or the extra-anatomic repair along with repair of associated intracardiac anomalies which may be conducted as either a single-stage or two-stage procedure. Also, in two-staged repair, the debate is which repair is to be done first, the timing of both of them and the type of procedure. ⁷ However, the other alternative approach involves percutaneous balloon dilatation for coarctation and a staged correction of the cardiac abnormality via sternotomy. ⁸ Another technique for coarctation correction is extra-anatomic cardiac bypass (ascending-to-descending thoracic aortic bypass) where via single incision (median sternotomy) associated cardiac abnormalities can also be addressed.^9,10

Edie et al. ¹¹ first introduced the extra-anatomic repair which is preferred by most of the surgeons. He performed a single-stage repair by successfully bypassing the coarctation segment using a Dacron graft which was anastomosed from ascending aorta to the descending aorta via thoracotomy and sternotomy with the graft assed anterior to the left hilum and anastomosed to the ascending aorta on the lateral aspect. ¹¹ In 1980, Vijayanagar reported the first post-pericardial ascending aorta to descending aorta bypass graft for CoA via sternotomy, with the graft being placed along the left margin of the heart. ¹² Powell later modified this technique by routing the graft around the right side of the heart, positioning it posterior to the IVC and passing anterior to the right inferior pulmonary vein, before anastomosing it proximally to the ascending thoracic aorta over the right lateral aspect. ¹³ The extra-anatomic bypass completely avoids manipulation of the coarctation segment and nearby collaterals thereby reducing risk of injury to nearby structures and reduces chances of bleeding. ²

The various advantages of extra-anatomic bypass from ascending aorta to DTA over ascending aorta to descending abdominal aorta are: (a) the full repair can be done using median sternotomy (b) eliminates need of laparotomy/thoracotomy (c) need of relatively small size graft, which reduces graft-related complications like infection. ¹⁴ However, the disadvantages of this approach are: (a) accessing the descending aorta can be challenging, often necessitating the elevation of the heart with the help of the heart-lung machine to maintain haemodynamic stability which becomes particularly difficult in obese patients or those with barrel-shaped chests, but it is crucial for performing a successful anastomosis, (b) it is essential to achieve a graft connection to the descending aorta without excessive bleeding, as managing such bleeding can be problematic and (c) additionally, there is a risk of esophageal injury during the procedure. ¹⁵

A single-staged approach was preferred in all our patients. We preferred the right-sided extra-anatomic approach in all our patients, similar to the approach used by Ma et al. and Duvan et al.^16,17 as this would keep the graft away from the sternum as far as possible. A right-sided extra-anatomic bypass is preferred because it not only avoids the graft passing near the left side of the heart but also strategically positions the graft away from the sternum, thereby significantly reducing the risk of injury or complications during any potential future re-sternotomies. Duvan et al. in their study had an aortic cross-clamp time of 72.83 ± 20.21 min, mean CPB time of 123.16 ± 29.74 min, ventilation time of 12.8 ± 5.9 h, ICU stay of 2.1 ± 0.9 days and hospital stay of 6.3 ± 1.5 days ¹⁷ which was comparable to the results of our study (mean aortic cross-clamp time of 149 ± 51.47 min, mean CPB time of 198.82 ± 52 min, ventilation time of 18 ± 15.6 h, ICU stay of 3.94 ± 0.83 days and hospital stay of 6.76± 1.68 days).

The choice between single-stage and two-stage repair for operating complex CoA associated with intracardiac abnormalities depends on various patient and procedural factors. The single-stage repair offers the advantage of addressing both CoA and the associated intracardiac defect in a single surgery, thereby reducing the overall number of procedures, shortening the total treatment timeline and minimizing cumulative surgical risks, ¹⁸ allows for an earlier complete anatomical correction specially in younger patients, fewer surgical incisions reduce post-operative pain, risks of infection and better cosmetic outcomes. ¹⁴ However, this approach comes with increased surgical complexity, prolonged CPB time and a higher immediate operative risk, particularly in patients with significant co-morbidities or critical conditions and few cases like in our study might require delayed sternal closure. ¹⁵ On the other hand, the two-stage approach allows for better stabilization of the patient between procedures, reducing the immediate surgical risk and enabling optimization for subsequent operations. ¹⁸ This strategy, however, requires multiple surgeries, which increases cumulative exposure to anaesthesia and surgical risks, while prolonging the overall treatment period during which the patient remains at risk for complications related to the uncorrected defect. ¹⁸ Both approaches have their respective merits and challenges, and the decision should be tailored to the individual patient's anatomy, physiology and clinical condition, as well as the expertise of the surgical team.

Our study highlights the advantages of the single-stage approach, with 94.1% of patients surviving without early or late mortality comparable with the study by Said et al. who also had 94% survival rate, whereas Duvan et al. and Ma Luyao et al. in their study had no mortality.^15–17 Okita et al. in their study of four patients who underwent simultaneous cusp sparing aortic root replacement and coarctectomy with total arch replacement from midline had 100% survival rate with no significant difference in BP between upper and lower extremities. ¹⁹ The mean age of our patients was 35.94 ± 12.70 years which is comparable to the study by Ma et al. (mean 43.8 years) and Duvan et al. (25.86 ± 8.4 years).^16,17 Significant haemodynamic improvements were observed, with ankle-brachial pressure gradients decreasing from 49.71 ± 7.35 mmHg to 11.18 ± 3.94 mmHg (p < 0.05) in our study which is similar to what was observed by Ma Luyao et al. (pre-operative 63.3±17.2 mmHg vs. post-operative 29.1±4.3 mmHg, p < 0.05) in their study. ¹⁶ Follow-up CT aortograms confirmed graft patency without complications, and patients were symptom-free after a mean follow-up of 4.81 ± 2.93 years. No patient in our study had any complication of oesophageal injury, graft kinking graft thrombosis, etc. on follow-up CT.

Conclusion

Single-stage extra-anatomic bypass from the ascending to the DTA, along with simultaneous correction of intracardiac abnormalities, can be a safe and effective option for managing complex CoA in adults as it provides significant improvements in haemodynamics, reduces the need for multiple surgeries and avoids many complications linked to extensive dissection of the coarctation segment.