SYMPATHECTOMY FOR PHERIPHERAL ARTERIAL DISEASE

LUMBAR SYMPATHECTOMY FOR PHERIPHERAL ARTERIAL DISEASEByDr E Aravind

HistorySympathetic denervation to treat occlusive arterial diseaseJaboulay(1889): periarterial sympathectomy on femoral arteryLeriche(1921): results disappointing due to reinnervation and vasospasm within weeks of operationRoyle(1924): observed after lumbar sympathectomy that skin and toes of ipsilateral foot became warm and dry

1930s-1950s: widely used for occlusive arterial disease because it was often the only alternative to amputationShort-lived and palliative

1960s: direct surgical revascularization replaced sympathectomy for treatment of occlusive arterial disease in most patients

AnatomyAfferent fibersOriginate in blood vessels, skin, visceraSynapse with dorsal root ganglion of spinal nerveEfferent fibersLocated in anteromedial column of spinal cordPreganglionic fibers travel to sympathetic chain, paravertebral or intermediate ganglia

Sympathetic outflow to lower extremities originates from spinal cord segments T10 to L3 and are conveyed primarily through L1 to L4 gangliaUsually 3 lumbar ganglia foundL1 and L2 fusedL2 and L3 Ganglionectomyusually sufficientCrossover fibers occur in 15% patients (usually L4)Complete sympathetic denervation of an extremity requires division of preganglionic fibers along their segmental origin and resection of the relay ganglionAnatomic completeness of sympathectomy is essential to minimize regeneration

PhysiologyGeneral principleSympathetic denervation results in increased blood flowVasodilation of arterioles in cutaneous beds

TechniquesUnder flouroscopic guidancePercutaneousAnesthetic leads to blockAlcohol/phenol leads tosympathectomyL1, L2, L3 injected

Operative TechniquesParamedian incisionretroperitoneal exposureSympathetic chain is medial to psoasOverlies transverse process of lumbar spineBeware of ureter, genitofemoral nerve, vascular structuresLaparoscopyBalloon dissection of retroperitoneum

Now the following questionsWhat are the physiological reasons for outcome after LS?What are the controversies for use of LS for PIDs?Is it possible to predict the therapeutic response to LS?What are the indications of LS today?

PHYSIOLOGICAL REASONSFOR OUTCOME AFTER LSThe resting blood flow in human skeletal muscle is 2-5ml/100g/minLS only increases this flow to 6-9ml/100g/minIn contrast with exercising muscle which will have the flow rate of 50-75ml/100g/min.Therefore, there is no physiological basis to use lumbar sympathectomy for patients with intermittent claudication since they already have maximal arteriolar vasodilatation.

Sympathectomy increases the transient blood flow through the collaterals by decrease in peripheral resistanceThus increase the skin blood flow and result in increased skin temperature, rather than true nutritional capillary blood flowTherefore, its usefull in rest pain and healing of ischemic ulcerationDivision of afferent pain fibers traveling in the sympathetic chain may be the alternative basis for rest pain.

But the vasomotor tone is usually normalized in 2 weeks to 6 months after operationThis transient effect of is due to supersensitivty of denervated sympathetic endings to circulating catecholamines and return of vasomotor tone by alternate pathways.

CONTROVERSIES FOR USEOF LS FOR PIDSAGAINSTNo improvement in nutritional blood flow after LSWith intra-arterial injection of radio-isotopes in the feet of patients with TAO found that LS does not improve microcirculationIncreased sympathetic nerve activity which may respond to LS has not been demonstrated which points to a local vascular abnormality in TAOComplications - failure of adequate denervation, brief paralytic ileus, hyperhydrosis, sexual dysfunction, and post-sympathectomy neuralgia.

FORIn selected patients with localized pre-gangrenous lesions, or superficial ischemic ulcerations in whom arterial reconstructive operation is not feasible or who refuse major vascular surgeryProvides only short-term pain relief and ulcer healing without long-term benefit in majority of patientsLS reduces pathogenetically reliable orthostatic and post-orthostatic spasm of the diseased arteriesA goal line last ditch stand and should be considered before a major amputation.

PREDICT THETHERAPEUTIC RESPONSE TO LSGood response is expected if there is no evidence of a somatic neuropathy, and if the tissue damage is not too extensive i.e., only rest pain, night pain, or digital gangrene is present.Deep infection or gangrene is a bad prognostic signTests of vasomotor tone:Increase of 2 degrees or more in skin temperature preoperative assessment of sympathetic nerve function byAcetylcholine sweatspot test Foot vascular resistance indexHillestad's reactive hyperemia test,Segmental impedanceplethysmography (irrigraphy), Skin thermometry,Measurement of arterial blood flow and resistance in the foot and in the leg,Reactive hyperemia underPhotoplethysmographic control, Thermographic testUsing Reserpine injected in the femoral artery

ASSESSMENT OF COLLATERAL CIRCULATIONAngiographyDoppler ultrasoundGood response is expected if ankle systolic pressure is above 60mmHg, preoperative Ankle Brachial Index (ABI) is >0.3, or if the distal thigh/arm index is >0.6.Patency of superficial femoral arteryTranscutaneous oximetry (TCPO2)Transmetatarsal TCPO2 is 0.3 and a patent femoral artery

ALTERNATIVE TO LUMBAR SYMPATHECTOMYEffects of iloprost in the treatment of Buergers disease relieves ischemic symptoms better than LS.2In the era of stable prostacyclin analogues, there is no reliable evidence to support the use of LS in Buergers disease.3This is cost effective than LS.4

1)P Agarwal, D Sharma. Lumbar Sympathectomy Revisited: Current Status in Management of Peripheral Vascular Diseases.The Internet Journal of Surgery. 2008 Volume 18 Number 1.2)Bozkurt Ak, Koksal C, Demirbas My, Erdogan A, Rahman A, Demirkilic U, et al.Turkish BuergersDisease Research Group. A randomized trial of intravenous iloprost (a stable prostacyclin ana-logue) versus lumbar sympathectomy in the management of buergers disease. Int Angiol.2006;25:162-83)Petronella P, Freda F, Nunziata L, Antropoli M, Manganiello A, Cutolo PP, et al.Prostaglandin E1versus lumbar sympathectomy in the treatment of peripheral arterial occlusive disease: ran-domised study of 86patients. Nutr Metab Cardiovasc Dis.2004;14:186-92.4)Cost Analysis of Alprostadil (Prostavasin) As treatment for Patients with PeripherAl Arterial disease stages iii and iv Compared with lumbar sympathectomy in mexico Carlos F.1, Gasca R.1, Aguirre.2, Naranjo M.21R A C Salud Consultores S.A. de C.V., Mexico City, Mexico, 2UCB de Mexico, S.A. de C.V., Mexico, D.F., Mexico