PATTERNS OF CHRONIC ISCHAEMIA OF THE UPPER LIMBS IN THE CENTRAL PROVINCE OF SRI LANKA

Introduction: A 30-year audit and management experience of chronic upper limb ischaemia in the Central Province of Sri Lanka is detailed. No previous Sri Lankan documentation on this topic exists. Materials and Methods: Data collected prospectively from 1974 to 2004 using a standard protocol was analysed. Results: Patterns of chronic ischaemic disorders seen dominantly among the 290 patients included in the study were, Aortic Arch Syndrome caused by both atherosclerosis (n=11) and Takayasu’s aorto – arteritis (n=7), Thoracic Outlet Syndrome (n=6), occlusion of major arteries of supply to the upper limb due to atherosclerosis (n=29), thromboangitis obliterans (n=188), giant cell arteritis (n=1), chronic arterial trauma (n= 2), chronic embolism (n= 3), haematological causes (n=4), Ergot induced vaso spasm (n=1), and vasculitides (n=38 ).Their management is detailed. Discussion and conclusions: Knowing the Sri Lankan patterns will help local clinicians to expedite it’s differential diagnosis.


Introduction
Chronic upper limb ischaemia (CULI) is less prevalent than chronic lower limb ischaemia. The better collateral circulation, the smaller muscle bulk and the less sustained demand may partly account for this difference. The lower prevalence of atherosclerosis in the arteries of the upper limb is a singular feature that also dominates the difference. The collateral source by a reversal of flow in the vertebral arteries (subclavian steal syndrome) remains an additional but risky resource in very proximal critical stenoses or occlusion of the subclavian artery. The reduction in collateral reserve caused by congenital anomalies of the ulnar, palmer and digital arteries 1 are unmasked by the earlier onset of ischaemia caused by small artery disease, in these patients 2 .
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY)

Figure 1: Common sources and sites of occlusion
The upper limb vasculature seems also to be more sensitive to triggers such as cold and emotion 3 and is followed by a vasospasm induced by sympathetic over activity 3 . Exposure to cold aggravates many aetiological mechanisms. They are changes associated with viscosity, the activity of the vascular endothelium, and local neural reflexes 3 .Smoking too aggravates digital ischaemia 3,4 .
Ischaemia of the finger or hand results in an excruciatingly painful state that invariably entails tissue loss, and often mandates intervention.
No studies of the aetiological patterns of this group of disorders have been documented in Sri Lanka. International patterns have been described 5,6,7 and we are documenting the differences observed in the local scenario of these patterns to help prioritisation in clinical decision making.

Materials and Methods
All patients with CULI, who presented to the Vascular Unit of the Teaching Hospital Peradeniya, during the 30 year period (1974 -2004) were prospectively audited on protocols. The data were computerised on spreadsheets and analysed. Data on the management of these patients were also documented during this period. Where operations were performed, records were kept and their results and follow up documented.
Ethical clearance to peruse these patient records was given by the relevant committee of the Faculty of Medicine, Peradeniya.

Results
Two hundred and ninety patients were included in the analysis.

Causes of Chronic Ischaemia of the Upper Limb
Majority (n=218, 75.2%) of the patients had underlying chronic occlusive arterial diseases (COAD) while 13.1% of the patients presented with CULI due to vasculitis. The aetiological breakdown is shown in Table 1. Figure 1 highlights the clinical distribution of lesions. The commonest presentation among the study population was loss of radial pulse (n=98, %). Table 2 shows the clinical presentation leading to a diagnosis of chronic ischaemia of upper limb (CULI) in this period.
The core blood pressure could not be properly assessed in all patients, but in those when it could be, 4 patients were hypertensive (ie > 160/90 mm of Hg). Two patients were diabetic and 6 of the 8 males were smokers. A non smoking male, was a diabetic. Eight others had other systemic systems involved, 2 patients with congestive cardiac failure and another 2 with chronic renal failure. They were not suitable candidates for major surgical reconstruction. Only patients 1, 5 and 11 (see Table 3) had clinical features of CULI, others were incidentally detected during clinical examination. and no attempt at reconstruction was made.    Only two patients warranted subclavian to subclavian prosthetic bypass and were completely relieved of their symptoms. Another patient managed conservatively, was followed up for 15 years and eventually regained her absent radial pulses and was completely asymptomatic by the age of 30 years.
Forty three (43/193, 22%) of the patients below the age of 49 years had superficial thrombophlebitis. and only 1 patient of the 25 patients over 50 years had thrombophlebitis. Further biopsy findings of specimens of digits (n= 43), and dissected distal forearm arteries of amputated limbs showed a thrombus within a artery which on light microscopy did not show any changes of ASO.
Level of pulse loss and the duration of ischaemia at presentation, is highlighted in Table 6. This does not reveal an overt proximal ascent with time.
Angiographic data on a few patients did not reveal any significant run off. Most patients were subject to short courses of vasodilator drugs namely nefidepine and guanethidine, failing which the patients were mostly relieved of their rest pain by cervical sympathectomies and amputation of their gangrenous digits.

Post Embolic Ischaemia (n=3)
Six patients presented secondary to embolism. In 3 patients with thoracic outlet syndrome, embolism followed post stenotic aneurysmal dilatation as has been previously described. 16 . Three other patients presented late with what seemed clinical features of embolism.

Case 1:
A 47-years-old female had developed an acute on chronic onset cold left forearm and hand at the beginning of this study. The left hand was cold and blue. The pulses were only felt up to the axillary artery. No lesion was detected in the heart, aortic arch or thoracic outlet though an axillary artery embolism was suspected. The limb was managed conservatively as was the practice then, recovered but developed mild forearm claudication on effort.

Case 2:
A 67-year-old male with angina developed an acute coldness leading to gangrenous ulceration of the right little finger tip one month previously which he then self traumatised. No pulse loss was detected. A primary site as a source could not be detected. Athero-embolism from an aortic source was suspected .A cervical sympathectomy was effective in relief.

Case 3:
A 55-year-old female was admitted with burning pain in both hands and Raynaud phenomenon of 3 month duration. She had a history of a thyroidectomy for thyrotoxicosis at 19, on admission both radial pulses were felt but were irregularly irregular, serum thyroxine was 14.1ug/dl and recurrent thyrotoxicosis with atrial fibrillation was diagnosed. The Raynauds of both hands was either unrelated or post embolic from a cardiac source. She was placed on carbimazole and an oral anti coagulant.

Drug induced Ischaemia n=1 (Ergot induced Vasospasm)
Case report: A-26-year old female professional, presented with a cold right upper limb. The coldness affected the digits, palm and forearm, 2 digits were cyanosed. The radial pulse was not felt and the brachial pulse was weak. The capillary return on the nail bed was slow. There was no wasting of the forearm muscles but tenderness of the forearm tissues and pain on stretching her right fingers was present. She had discomfort whilst using the right upper limb and the entire episode was less than a week's duration. She did not have rest pain. The other limbs were normal. Angiography showed the right arm and forearm vessels were of very narrow but of uniform calibre. She has been on ergot tablets for migraine for approximately three months. On stopping the ergot tablets she made a complete recovery in 5 days without intervention. The dose of ergot had unfortunately not been recorded.

Vasculitis (n= 38)
Many patients presented with Primary Raynaud's Disease, but were not included. They were mostly young women with painless discolouration of fingers .classically showing sequential pallor, cyanosis and crimson colour on reperfusion as time elapsed (Raynauds phenomenon) ( Table 7).
Scleroderma was diagnosed on the basis of patients who had a previous medical diagnosis based on microstomia, dysphagia, high ESR and on cutaneous biopsy. Those with secondary Raynauds had painful finger/s with Raynauds phenomenon, ie similar colour changes. Common presentations often included a spindled (due to pulp atrophy) finger or fingers of one or both hands. Minor ulceration, coldness, rest pain, pre gangrene and occasionally gangrene were features. 3 of these patients had a positive rheumatoid factor on serology.
Two patients with malignancy came with secondary Raynaud's of a single digit and were thought to result from a gammopathy causing elevated viscosity. . The Raynaud's phenomenon responded to the resection of the colonic cancer and the management of myeloma.
Management included a careful study of the protean causes of vasculitis and treatment of the disease. Procedures to improve the vascularity included cervical sympathectomy often done via the neck, if a local anaesthetic to the stellate ganglion was helpful to relieve the pain.
No patients were seen with Hypothenar Hammer Syndrome or cold induced immunoglobulins.

Discussion
The striking prevalence of CULI in Sri Lanka compared to most western international literature, 5,6,7 is due to the disorder Thromboangiitis Obliterans (TAO). . Collagen disorders and those caused by trauma ie vibratory white finger and hypothenar hammer syndrome are significantly uncommon in comparison to the west 5,6,7. . The warm climate could be argued to be a factor. 3 The other causes of transient digital ischaemia such as Primary Raynauds disease, were not included in our study.
Recent studies 8 have shown some claudication handicaps if the traumatised vessel is simply tied off and every encouragement is given to reconstruct the artery. In the first case above with chronic trauma of a mainline artery, technically poor reconstruction and delay should have been avoided. Chronic arterial injury with the development of an arterio-venous fistula ,highlighted in case 2., illustrates the distal ischaemia that can result from shunting caused by fistulation as occurs sometimes, even in iatrogenic constructions for vascular access 9. Likewise upper limb embolism, formerly managed conservatively 10 is now thought to need a more active approach to avoid ischaemic symptoms like claudication, loss of delicacy of hand movements , and the loss of sensitivity of the digits especially if the dominant limb is involved 11 .
The centrifugal force and the sheer effect on the aortic arch are thought to be responsible for the development of a ASO plaque at that site with spill over ASO into the arteries arising from the arch. The stenoses, the occlusions, the emboli arising from unstable plaques lead to cerebral ischaemia or to upper limb arterial compromise. It is seen in the cases we highlighted in this study. The forty year age group involved in our study is about a decade or two younger than western series 12 This leads to a possibility, as we have no histological data, to the possibility of us having included some patents with Takayasu's aorto arteritis into this group though the ESR was normal.. Appearances on aortography (n=11) showed all 11 to have subclavian stenoses or occlusion but only three presented with ischaemic features in their ipsilateral upper limbs, on presentation. They were referred to the vascular clinic with loss of brachial pulse and for their neurological features accompanying the carotid pulse loss or the presence of a carotid bruit. Our study also reflected the systemic nature of the ASO in these cases as has been shown to be common in the West. 12 Further, subclavian steal syndrome 13 was seen in two of our patients.
Those with upper limb ischaemia with aortoarteritis were probably selected for referral to the vascular clinic. A slightly greater prevalence of males in those presenting with CULI were seen compared to other studies. 14,15,16 . The natural recovery of a young patient (1, Table 4), is noteworthy.
A detailed study of cervical rib compression and its complications have been made earlier by the first author. 17 Management by early embolectomy would have been the way to avoid ischaemia in this group. 16 Reconstructions are risky once the distal arterial run off becomes filled with episodic bouts of embolisation. Drug induced ischaemia, a classical case is described. Similar experiences, has been documented 18 .
Vasculitides presenting with digital ischaemia posed a major problem especially in the dominant limb. It was usually painful and tissue loss was either present or was imminent. We probably saw most cases admitted in the Central Province. 38 cases over 20 years does not amount for much and highlights the relatively low prevalence at present .compared to the West 19 . The significant absence of Hypothenar hammer syndrome is a feature.
Among the patients with occlusive arterial diseases, 43.1% of the patients were below the age of 35, dominantly male, heavy smokers with a significant prevalence of thrombophlebitis with a no prevalence of diabetes and a low prevalence of hypertension and systemic occlusive arterial disease of the heart and brain. These patients under 35 years were afflicted almost exclusively by Thrombo angiitis obliterans (TAO).This was true of a significant proportion in those afflicted in the under 49 age group as well.
In conclusion the dominant disorder causing CULI in our study was due to the prevalence of TAO. Encouraging the patients to stop smoking and the use of cervical sympathectomy and digital amputations were the mainstays in our management. This data we hope will provide a scaffolding for clinicians to make a diagnosis.