A 24 year old male patient with weakness in the left upper limb

This article has no abstract. The first 100 words appear below:A 24 year old male attended the outpatient department of a local hospital with the chief complaints of pain in the central chest for two years and easy fatigability of the left upper limb for one and half years. After performing various examinations and investigations, he was sent to Al Helal Specialized Hospital with the preliminary diagnosis of coarctation of the aorta. The pain was dull aching in nature, continuous in duration, mild in intensity mostly, but sometimes intense sharp stabbing, radiating to the back. There was no known aggravating factor but lying down relieved it partially.


Presentation of Case
Dr. Redoy: A 24 year old male attended the outpatient department of a local hospital with the chief complaints of pain in the central chest for two years and easy fatigability of the left upper limb for one and half years.After performing various examinations and investigations, he was sent to Al Helal Specialized Hospital with the preliminary diagnosis of coarctation of the aorta.The pain was dull aching in nature, continuous in duration, mild in intensity mostly, but sometimes intense sharp stabbing, radiating to the back.There was no known aggravating factor but lying down relieved it partially.The pain was not associated with meal, palpitation, cough, fever.The patient also complained of easy fatigability of the left upper limb, which was aggravated by work and relieved by rest.It was not associated with shortness of breaths.The patient also complained of a headache which got aggravated by stress and relieved upon taking rest.He had no history of any chronic illness like diabetes, hypertension, jaundice, bronchial asthma, bleeding dyscrasias and had never undertaken any major surgical procedure.
His general examination revealed otherwise normal finding but for his blood pressure of 140/90 mmHg in the left upper limb, 130/80 mmHg in the right upper limb and radiofemoral, and brachiofemoral delay, and decreased pulse volume in the lower limb.Cardiac examination revealed a systolic murmur in the left infraclavicular area.His other systemic examinations including central nervous system, abdominal and respiratory examinations were normal.
With these complaints, he was further investigated by routine and specific investigations (Table I).All laboratory investigations, ECG, chest X-ray, ECHO and spirometry were performed.His serum creatinine was 1.2 mg/ dL.ECHO revealed coarctation of the aorta.Then a magnetic resonance aortography was performed to evaluate and plan the further management (Figure 1).
The patient was admitted with a plan for surgery.On the basis of history, physical findings and investigations I would like to draw my provisional diagnosis.

Differential Diagnosis
Dr. Redoy: Coarctation of the aorta 1 is a condition characterized by narrowing in a part of aorta. 2 It is most exclusively congenital, 3 but can also be acquired extremely rarely. 4Coarctation of aorta comprises 4-8% of congenital heart disease cases. 57][8][9] It is twice as more common as in males than females. 10The most common site of coarctation is juxtaductal, while the former classification of coarctation of aorta was based on the location of PDA viz.preductal, ductal and post-ductal. 11, 12Coarctation may be rarely present at other sites eg: abdominal aortic coarctation, either congenitally or acquired. 13e underlying pathophysiological mechanism of coarctation of the aorta is probably due to abnormal ductal tissue infiltrating onto the juxtaductal aorta.This contractile ductal tissue upon synchronous contraction during ductal closure results in luminal narrowing. 14ststenotic dilatation and jet lesions of the descending aorta immediately distal to the coarctation segment is usually present. 15,16  sign and symptoms of coarctation of the aorta vary according to the age of presentation and constriction of the PDA. 17Preductal subtype of coarctation is usually becomes symptomatic in the neonatal period and they often have hypoplasia of arch. 11These patients with unsuspected critical coarctation may have systemic hypoperfusion, metabolic acidosis and congestive heart failure (tachypnea and feeding difficulty).After the closure of ductus, the patients may develop features of end-organ failure (renal dysfunction, hepatic failure, intestinal ischemia and severe metabolic acidosis) due to compromised blood flow to abdominal organ and lower limbs. 17, 18On physical examination of the patient with coarctation of the aorta may have a difference in peripheral pulse examination with good volume upper limb pulse and weak lower limb pulse as seen in our case.As the symptomatic patient may have murmur or hypertension, headache, angina, exercise intolerance or hypertension not responding to antihypertensive medications are seen in the young adult.Brachiofemoral pulse delay, diminished or absent femoral pulse and difference in blood pressure in upper and lower limbs are commonly seen in all patients. 19. Heemel: According to ACC/AHA 2008 guidelines (adapted), clinical evaluation and follow-up of coarctation of the aorta in adults should be done (Class I) by checking brachiofemoral pulse difference and ABPI.TEE is recommended for suspected aortic coarctation.Thoracic aorta and intracranial vessels should be evaluated by MRI or CT scan in all patients with coarctation of the aorta.
Class I recommendations for intervention and surgical treatment of coarctation of the aorta in adults depends upon peak to peak coarctation pressure gradient where ≥20 or <20 mmHg with radiological evidence of narrowing and collateral flow suggest intervention.Surgical procedure for previously repaired coarctation is recommended if a long segment is involved and there is concomitant aortic arch hyperplasia.
After surgical correction, it is recommended (Class I) to have long-term follow-up, at least once yearly.Post-operative thoracic aortic imaging is advised for assessing aortic dilatation or aneurysm formation.CT/MRI is suggested 5 yearly or less to evaluate repair site of coarctation. 20

Dissection of aorta
Dr. Mayank: Aortic dissection is a dreadful condition in which pulsatile blood passes in between and separates the aortic media and the adventitia. 21he length of the lesion may be so variable that it may extend along the proximal or distal and even the whole aorta and its branches. 22This intimal tear usually develops in the ascending aorta but may also develop in upper descending aorta just beyond the left subclavian artery origin. 23    spaces or due to regurgitation if dissection causes aortic valve shear. 24Most patients who die acutely are due to false channel rupture causing hemopericardium, hemomediastinum or hemothorax. 25There is no definite sign or symptom to definitely identify acute aortic dissection.Classic clinical manifestation is a sudden onset of severe tearing or ripping chest pain.The site of pain can indicate the involving area.Neck or jaw pain results when the aortic arch is involved or the lesion is extended into the great vessels.When the anterior arch or aortic root dissection is involved, it results in anterior chest pain and dissection of descending aorta results in intrascapular pain.The chest pain may be mild or no pain in some cases. 26

Patent ductus arteriosus (PDA)
Dr. Dharmendra: Based on the typical finding of systolic murmur in the left infrascapular area, this could be a case of PDA.PDA is a congenital defect in which the proximal part of the descending aorta is connected to the roof of the main pulmonary artery where the left branch of the pulmonary artery is originated.The ductus is essential for the survival of fetus but the patent ductus beyond the neonatal period is abnormal. 27rmally, after birth, the sudden increment of oxygen pressure causes the inhibition of ductal smooth muscle voltage-dependent potassium channels.Calcium enters the cell and the duct is constricted. 28The placenta along with functioning lungs increase the metabolism of PGE2 and PGI2 that eliminates and decreases the level of the prostaglandins.The wall of the ductus is thickened and lumen is obliterated and shortened due to contraction of the medial smooth muscle fibers Functional closure usually occurs in 24 to 48 hours after birth in term neonates and within the next 2 to 4 weeks, the endothelium is unfolded along with subintimal disruption and proliferation, which results in the permanent seal. 29The resulting fibrous band with absent lumen is called as ligamentum arteriosum.

Interrupted aortic arch
Dr. Heemel: Absence of luminal continuity between the proximal aorta and the distal aorta is known as an interrupted aortic arch.Fibrous strands that are connecting two widely separated aortic ends are also included in interruption of the aortic arch and not under coarctation of the aorta.The aortic arch morphologically may be interrupted at three sites. 30ype A is the interruption just distal to the left subclavian, with blood flowing to the descending aorta through the ductus arteriosus.It is seen in 40% of cases.Type B, seen in 55% of cases, is the interruption between the left subclavian and left common carotid arteries.Type C is the interruption located between the left common carotid and left brachiocephalic arteries, which is seen in 5% of cases.In all forms of interruption, the flow is through the proximal ascending aorta through the ductus arteriosus to the distal descending aorta, except in rare cases when the ductus is absent or closes during fetal life. 31

Discussion
Dr Heemel: How will you then proceed with your diagnosis?
Dr. Redoy: Generally the provisional diagnosis of coarctation of aorta can be drawn on the basis of physical examination.Differential blood pressure and delay in pulse are pathognomic.The physical findings may be noted are frequently the patients have normal appearance except in cases when coarctation compromises origin of the left subclavian artery in which case the left upper limb may be smaller than the right upper limb.Also, there may be the presence of other associated physical deformities. 19terial pulses and blood pressure examination of upper and lower limbs may show delayed and diminished pulse and differential blood pressure like delayed brachial to femoral pulses.Typical murmurs and sounds on auscultation may be found like continuous or late systolic murmur may be heard over posterior part of the thoracic spine, aortic ejection sound, bilateral collateral arterial murmurs, early diastolic murmur of aortic regurgitation short mid systolic murmur. 32 Mayank: What is the relevant anatomy of the region to consider planning for surgery?
Dr. Dharmendra: The arch of the aorta and great vessels and the insertion of ductus are the most relevant structures for understanding the coarctation of aorta. 33As coarctation and interrupted aortic arch can occur anywhere along the arch aortography is essential to identify the emergence of the great vessels and especially ductus arteriosus. 34The ductus is a remnant of the sixth left aortic arch which connects the aorta with the pulmonary trunk in the fetus.It is connected to the concave undersurface of the aortic arch directly opposite to either the left common carotid or left subclavian artery.The left recurrent laryngeal nerve hooks around the lower border of the ductus arteriosus.So, it may be easily injured during operation if care is not taken.Also due to the coarctation, there is post-stenotic dilatation, and the thoracic vessels may be dilated. 35. Heemel: What investigative modalities will you choose to confirm your diagnosis?Dr. Mayank: Aortography by CT or MRI can confirm the diagnosis, and other diagnostic modalities like chest X-ray may reveal 'inverted 3 sign'.Thoracic ECHO can and transesophageal ECHO may reveal coarctation site, narrowing dimensions, and pressure gradient determinations. 36. Dharmendra: What are the treatment plan for this case?Dr. Mayank: After adequate optimization of the patient, any of the following plans can be chosen based on the condition of the patient.Subclavian flap aortoplasty, Resection of the coarcted aorta with an end to end anastomosis, resection followed by an end to end anastomosis with subclavian aortoplasty, patch graft aortoplasty, aortosubclavian bypass, aorto bypass, balloon aortoplasty and stenting. 37 Redoy: Why do you propose aortosubclavian bypass in this case?
Dr. Asit: The subclavian girth was larger, so a prosthetic conduit from subclavian to distal aorta was the best option and compared to all procedures this was the best suited for this patient.
Dr. Redoy: Would not there occur any complications, namely steal of blood?Dr. Dharmendra: As the size of the subclavian vessel is large, there will not be any steal of blood by aorta from the subclavian, thus sparing any perfusion related complication from the left upper limb.
Dr. Heemel: How to manage this patient intraoperatively from the anesthetic point of view?Dr. Sanjoy: From the anesthetic point of view, just like other cardiovascular system surgeries, we took optimal precaution and planning.The aspects like monitoring, adequate heparinization, acidosis and the other parameters were considered.As a sidebiting clamp was used, there is the minimum to no risk of acidosis.In regards to heparinization for prosthetic conduit, it was discussed with surgeon previously during planning.To achieve a target ACT of 300, we used 1-1.5 mg/kg of heparin.For monitoring, we placed an arterial catheter in right as well as left hand.Right hand for pressure monitoring and left to see for occlusion.[40]

Final Diagnosis
Coarctation of aorta Dissection of the aorta is classified according to DeBakey or Stanford classification based on the extent of progression of dissection.Aortic dissection can be catastrophic, and patients may die even before reaching the emergency service or diagnosis is confirmed.An alternative presentation is a hypovolemic shock.It may be a result of recent blood loss or extravasation into periaortic BSMMU J 2018; 11: 236-240

8 ¶
Reference values are affected by many variables, including the demographics and the laboratory methods used.The ranges used at the Bangabandhu Sheikh Mujib Medical University Hospital are for adult who do not have medical conditions that could affect the resuls.They may, therefore, not be appropriate for all patients.

Figure 1 :
Figure 1: Magnetic resonance aortography of the patient showing coarctation after left subclavian artery