Balloon Angioplasty in Coarctation of Abdominal Aorta

Introduction

Coarctation of the aorta is an obstruction in the descending aorta located at any place but almost invariably at the
insertion of the ductus arteriosus. Coarctation varies considerably in its anatomy, physiology, clinical presentation, treatment options, and outcomes. Though it is usually a discrete lesion, Coarctation may consist of a long segment stenosis, may be associated with tubular hypoplasia of the transverse aortic arch or abdominal in location. Long segment Coarctation of the abdominal aorta is rarely reported in our country. The diagnosis was suspected in this case from the history and clinical examination and it was confirmed with echocardiography and aortogram. Later balloon angioplasty was performed with good result. So far our knowledge goes, this is the first case of balloon angioplasty of abdominal Coarctation in Bangladesh Armed Forces.

Case Report

A 13 years old girl, reported to the pediatric cardiology unit of combined military Hospital (CMH) Dhaka as a referred case from Dinajpur on 29th October 2000. Her problems were severe, headache and paroxysmal attack of brief unconsciousness over a period of one year. She was diagnosed as a case of essential hypertension by the local physicians and was on antihypertensive medicine since then. On subsequent examination her femoral pulses were found very weak, her upper limb blood pressure was 170/100 mmHg and lower limb blood pressure was 100/70 mmHg. She developed the transient fit and passed urine in front of a doctor during the examination. Routine investigations were found normal. CT scan of the brain was normal. Echocardiography showed left ventricular hypertrophy with severe Coarctation of abdominal aorta. Peak Pressure gradient across Coarctation segment was 60 mmHg. ECG showed left ventricular dominance. She was diagnosed as a case of severe coarctation of abdominal aorta with the generalized seizure. Balloon angioplasty of Coarctation was performed on 31st October 2000.

Equipment Used

Equipment: Standard pediatric cardiac catheter pack, Regular pediatric drapes, Pressure tubing red and blue line x 1, 20 leader catheter x l, NIH marker catheter x 1, GL catheter x 1, MPA catheter x 1, 0.38 Teflon wire x 1 x 260 cm, 10mm x 4cm balloon x I. Medications: Inj Lignocaine 2%, Injection heparin, Injection ketamine, Injection midazolam, Injection atropine.

Procedure Followed

The patient was placed on the table and arms secured above the head and the legs strapped. The patient was connected to ECG monitoring and pulse oximetry, both groins were anesthetized with 1 % lidocaine. 20 leader catheter was introduced to the right femoral artery (RFA) and a sample for blood gas analysis was taken. A 6F sheath was introduced to a right femoral vein (RFV) and 6F NIH marker catheter was advanced. Saturation and pressure run was done in all chamber of the right heart i.e. Superior vena cava (SVC), Inferior vena cava (IV C), Innominate, RA, RV, MPA etc. Cine angiogram was obtained in the right ventricle. 20 leader catheter in RFA was changed with 6F sheath and 6F MPA cook catheter was used for saturation and pressure run in the left heart. Aortogram was performed. A long segment coarctation of abdominal aorta was detected with a pressure gradient of 60 mmHg across it. Balloon size was determined by using the following formula.
x/y X10mm = Stenotic area.
Y=Width of the aorta above the level of coarctation.
X=Distance between the marker of NIH marker catheter. (Distance took from a cine angio in superior vena cava).

10 mm = Known distance between the marker. The stenotic area was 8 mm from above calculation. A 10
mm X 4cm balloon was selected for angioplasty. The balloon was prepared by aspiration. Indeflator device
was prepared with a dye solution. The balloon was kept on negative pressure and injection heparin 50 units/kg was given to a patient.

The MPA catheter was exchanged with a balloon catheter with the help oh 0.35 exchange 0.35 mn wire. The balloon was advanced to the desired position and inflated 4 times up to 6-atmosphere pressure. The balloon was then replaced with MPA cook catheter with the help of exchange wire and pressure run was done. Aortogram was performed again to see the result.

Then the catheter was withdrawn and the withdrawal gradient recorded. The pressure gradient across coarctation dropped down to 20 mmHg. All access lines were removed. Patients blood pressure came down to 120/75 mmHg. She was discharged from the hospital after 24 hours.

Discussion

Nine percent (9%) of all children with congenital cardiac defects have some degree of coarctation of the aorta. The majority of patients with coarctation of the aorta are usually male (56%), are asymptomatic older children, adolescent or adult12.

Coarctation of the abdominal aorta is a rare lesion that is often associated with renal artery stenosis as well3,4. In this case, renal artery stenosis was absent. It is very difficult to explain the cause of abdominal coarctation but the hemodynamic theory of’ coarctation suggests that it develops as a result of hemodynamic disturbances that reduce the blood flow through the fetal aorta, arch, and isthmus. Coarctation commonly presents later in childhood as systolic hypertension or as a heart murmur. The most common cause for referral is hypertension in upper limbs or the presence of heart murmur6. This patient presented with hypertension and fit. The fit was may be related to hypertension as CT scan of the brain was normal.

Balloon angioplasty for coarctation was first reported in 1982. Surgical correction of coarctation is accomplished by resection and end to end anastomosis. Subclavian flap aortoplasty can also be done. An unresolved issue is the role of balloon angioplasty for treating coarctation because of the risk of aneurysm formation and restenosis. A native aortic coarctation can be dilated with good initial relief of the gradient. Immediate gradient reduction is similar after balloon coarctation angioplasty and surgical treatment of unoperated coarctation of the aorta.

The risk of aneurysm formation and restenosis after angioplasty are higher than surgery, although the other risk is similar9. Recurrent coarctation after repair of aortic coarctation is not uncommon, with an incidence varies from 16% to 60%. The role of’ angioplasty in re-coarctation is excellent. Formerly, this re-coarctation were managed with reoperation, but in recent years balloon angioplasty has become the preferred treatment10. Any residual gradient of more than 25 measured at rest should suggest this therapy. Surgical repair of recurrent coarctation of the aorta
can be performed safely. Sakopoulos et al11 in their study showed more than 96% (n=56) success rate with prosthetic patch technique.

If we consider the hospital charges for treatment it is much less in the balloon angioplasty group, though the failure rate was found higher than surgery in Shrin et al12 studies.

For female patients outcome of pregnancy following intervention is an important factor to think about. Sadi AS et al carried out a study in Texas children Hospital showed excellent outcome. The occurrence of congenital heart disease in of spring was only 3%.

Biswas – PK et al14 carried out two years follow up of 29 cases in an institute of postgraduate medical education and research Calcutta showed < 10 mmHg pressure ‘gradient across the coarctation in 27 cases (n=29). Restenosis appeared in two patients, the aneurysm was found in one patient and mild dissection in three patients.

Conclusion

The immediate result of balloon coarctation angioplasty is very good. As a surgical facility for children is very limited in our country We Should go for balloon angioplasty for native coarctation or recurrent coarctation of our patients. Follow up at 3 months interval should be required for these cases to look for restenosis or aneurysm formation.