and Dhananjaya Sharma2
(1)
Department of Surgery, NSCB Government Medical College, Nagpur Road, Garha, Jabalpur, 482003, MP, India
(2)
Department of Surgery, Government NSCB Medical College, Nagpur Road, Garha, Jabalpur, 482003, MP, India
Keywords
Lumbar sympathectomyCritical limb ischemiaManagementIntermittent claudicationRest painAmputationDisease is very old and not much about it has changed. It is we who change as we learn to recognize what was formerly imperceptible.—Charcot
Introduction
Lumbar sympathectomy (LS) has been used in the treatment of various vascular and neurological disorders of lower extremities for close to 80 years [1].
The concept of sympathetic denervation as a mode of therapy for arterial occlusive disease was first described by Jaboulay in1889 in the form of periarterial sympathectomy on femoral artery. Leriche [2] states that results are disappointing due to reinnervation and vasospasm within weeks of operation. Lumbar sympathectomy (LS) or section of the lumbar sympathetic chain and excision of one or more ganglia was introduced by Royle in 1923 in the treatment of spastic paralysis of the lower extremity, and he observed after lumbar sympathectomy that the skin and toes of ipsilateral foot became warm and dry due to increased circulation. By the 1940s, lumbar sympathectomy became the primary surgical treatment of atherosclerotic occlusive disease and its sequelae in the lower extremity because it was often the only alternative to amputation. However, the development of direct arterial reconstructive procedures in the 1950 diminished the importance of LS as a primary operation.
LS is acknowledged to have a role in the treatment of patients with reflex symptomatic dystrophy (causalgia), vasospastic disorders like acrocyanosis and Raynaud’s syndrome, hyperhidrosis of the hand and feet, symptomatic vasospasm, and non-reconstructable arterial occlusive disease. A literature survey finds its miscellaneous uses for frostbites, desiccation of chronically moist ulcerations between the toes, chronic renal pain, rectal tenesmus, and sympathetically maintained intractable pain due to malignant reasons. Although it is the most commonly performed operation in the developing countries for critical limb ischemia (CLI), there is considerable controversy about its usefulness.
Anatomy
In the lower extremity, the lumbar sympathetic system exerts anatomic control over the vasoconstriction and sweating. Preganglionic neurons in the lateral gray substances of the spinal cord from the level of T10 to L2 or L3 send axons along the ventral nerve roots to the lumbar sympathetic ganglia via white rami communicantes. Preganglionic fibers then synapse within the ganglion or ascend or descend as the interganglionic part of the sympathetic chain to synapse with postganglionic neurons in the ganglion of the chain. The postganglionic fibers exit through gray rami communicantes to accompany the peripheral nerves.
Postganglionic fibers may arise from the first to the fourth or even fifth lumbar ganglion to travel with the lumbar and sacral nerves to the lower extremities. The foot and leg below the knee are primarily supplied by postganglionic fibers from the L3 level and below [3].
The lumbar sympathetic trunk contains 4–5 ganglia. They lay retroperitoneally in front of the vertebral column along the medial borders of the psoas major muscles. Four ganglia are usually found in the lumbar chain, but the number may vary between two and eight, and rarely one continuous ganglion is found [4].
Although the variations in position of the ganglia are common, the second and the fourth lumbar ganglia are the more constant ones.
The number of rami of any ganglion and their position between the spinal nerves and lumbar sympathetic trunk show considerable variation. Cross communication between the right and left sympathetic trunk are also variable [5]. Knowledge of these variations in the anatomic structure may be helpful in performing correctly a lumbar sympathectomy. It is to be mentioned here that because most vascular problems that may require sympathectomy are confined to the foot, resection of 2nd–4th lumbar ganglia is necessary.
The Procedure
There are three approaches for lumbar sympathectomy anterior, anterolateral, and posterior. The anterolateral approach is most popular because the incision is well tolerated, dissection remains retroperitoneal, exposure is adequate, and both sides can be done in one sitting. Anterior approach is selected when any associated intra-abdominal or intraperitoneal procedures like repair of aortic aneurysm are undertaken or other intraperitoneal procedure. Posterior approach is not favored because it is associated with severe postoperative paraspinal muscle spasm.
In anterolateral approach patient lies supine with 30° tilt to opposite side. A transverse incision is placed in the loin extending from anterior axillary line to lateral border of rectus (Fig. 40.1). Muscles are split, and peritoneum is displaced medially and forward off the posterior abdominal wall (Figs. 40.2 and 40.3), the genital vessels and ureter being raised along with it. After proper dissection the lumbar sympathetic chain is located medial to the psoas muscle and lies over the transverse process of lumbar spine. The left lumbar ganglia lie adjacent and lateral to the abdominal aorta and on the right, just beneath the edge of the inferior vena cava.
Fig. 40.1
Transverse incision is placed in the loin extending from anterior axillary line to lateral border of rectus
Fig. 40.2
Muscles are split in full length of skin incision
Fig. 40.3
Peritoneum is displaced medially and forward off the posterior abdominal wall
Tactile identification of the lumbar chain by plucking discloses a characteristic “snap” as a result of tethering of the nodular chain by rami communicantes. Other vertical band-like structures in this region like genitofemoral nerve, paravertebral lymph nodes, or ureter do not recoil as briskly. Once identified the midportion of the sympathetic chain is dissected free of surrounding tissues and retracted with a right-angled clamp or a nerve hook to draw it up (Fig. 40.4). The first lumbar ganglion is sought high up in under the crus of the diaphragm, and fourth ganglion is obscured by common iliac vessels. The surgeon facilitates orientation and ganglion numbering by identifying the sacral promontory and an adjacent lumbar vein that usually crosses the sympathetic chain in front of or behind the third lumbar ganglion. The chain and at least two lumbar ganglia are removed and hemostasis done [6].
Fig. 40.4
Sympathetic chain is dissected free of surrounding tissues and retracted with a right-angled clamp or a nerve hook
The technique of laparoscopic LS has gained popularity in recent times. The time-tested instruments, dissection maneuvers along with videoscopic magnification, that have proved so effective in thoracoscopic dorsal sympathectomy are employed in LS [7].
Complications of Lumbar Sympathectomy
Major complications result from failure to appreciate normal anatomic relationships with resultant injury to the genitofemoral nerve, ureter, lumbar veins, aorta, and inferior vena cava. The most common complications following LS are post-sympathectomy neuralgia, sexual dysfunction, and failure to achieve the desired objectives of pain relief or tissue healing.
Post-sympathectomy Neuralgia
It usually begins 1–2 weeks after LS and appears in up to 50 % of patients. It is localized to the thigh (anterolateral), worse at night, and rarely responds to medications. It usually remits spontaneously within 8–12 weeks.
Sexual Dysfunction
It consists of retrograde ejaculation, and occurs in 25–50 % patients undergoing bilateral LS including the L1 sympathetic ganglia.
Failed Lumbar Sympathectomy
Failure to achieve the desired objective of pain relief or tissue healing is blamed on several factors. These include an incomplete sympathectomy as a result of a technically incomplete operation or as a result of cross innervation that makes a complete sympathectomy impossible. The latter recurrence may be caused by regenerating nerves or increased function of previously inconsequential crossed fibers.
Surgical vs. Chemical Sympathectomy
Surgical sympathectomy is defined as the surgical ablation of the cervicothoracic or lumbar sympathetic chain by means of open or laparoscopic procedure. Chemical sympathectomy is the percutaneous ablation of the cervicothoracic or lumbar sympathetic chain by the injection of phenol or alcohol solution. This procedure promotes a prolonged but not permanent sympathetic denervation.
Review
On the one hand, the advent of laparoscopic lumbar sympathectomy and reports of LS in conjunction with omental transposition have maintained interest in this procedure. On the other hand, rapid development of various arterial reconstructive procedures, description of distraction osteosynthesis, and availability of gene transfer technology has added to the confusion concerning the proper place of this procedure in the management of thromboangiitis obliterans (Buerger’s disease) and other CLIs. Being aware of these inconsistent opinions, we decided to try and define the place of LS for the management of thromboangiitis obliterans by evaluating the currently available evidence and to answer the following questions:
What are the physiological reasons for outcome after LS? What are the controversies for the use of LS for CLI? Is it possible to predict the therapeutic response to LS? What are the indications of LS today?
What Are the Physiological Reasons for Outcome After LS?
Clinical response after lumbar sympathectomy is variable and transitory. This can be partially explained by physiological changes in the skin and muscle blood flow after sympathectomy. The resting blood flow in human skeletal muscle is 2–5 ml/100 g/min; elimination of all sympathetic vasoconstrictive activity only increases this flow to 6–9 ml/100 g/min in contrast with exercising muscle which will have the flow rate of 50–75 ml/100 g/min. [8]. Ischemia and exercise both produce metabolic substances locally, which cause maximal vasodilatation, despite sympathetic discharge; therefore, there is no physiological basis to use lumbar sympathectomy for patients with intermittent claudication since they already have maximal arteriolar vasodilatation [9, 10]. While sympathectomy cannot increase exercise hyperemia, it increases the collateral blood flow provided there are enough collateral vessels and vascular pliability. Sympathectomy increases the transient blood flow through the collaterals in an ischemic extremity as a result of the decrease in peripheral resistance due to opening of arteriovenous anastomoses with marked reduction in peripheral resistance, thereby increasing blood flow. These arteriovenous anastomoses have little or no intrinsic myogenic tone but are dependent upon sympathetic vasoactivity to control their diameter [11–13]. All these mechanisms increase the skin blood flow and result in increased skin temperature, rather than true nutritional capillary blood flow [14]. Therefore, its use in rest pain and ischemic ulceration is well accepted. The vasomotor tone is usually normalized in 2 weeks to 6 months after operation; this transient effect of LS can be explained by Cannon’s law of supersensitivity of denervated sympathetic endings to circulating catecholamines and return of vasomotor tone by alternate pathways [15, 16]. The division of afferent pain fibers traveling in the sympathetic chain may be an alternative basis for the success of lumbar sympathectomy, especially in rest pain [17].
What Are the Controversies for the Use of LS for CLI?
The place of LS in the treatment of CLI of the lower limbs remains controversial ; inconsistent opinions on its value can be divided into those who are against and those who are not.
Against
Assessment of cutaneous blood flow in the foot in patients with critical limb ischemia failed to detect improvement in nutritional blood flow after LS [18]. Investigators assessing microcirculation (with intra-arterial injection of radioisotopes) in the feet of patients with TAO found that LS does not improve microcirculation and concluded that there is breakdown of the microvascular defense system from the beginning of the disease [19]. In fact, even the presumed increased sympathetic nerve activity which may respond to LS has not been demonstrated which points to a local vascular abnormality in TAO [20]. LS, like any other surgical procedure, is not without its share of complications which include failure of adequate denervation, brief paralytic ileus, hyperhidrosis in parts of the body which remain normally innervated, sexual dysfunction, and post-sympathectomy neuralgia. The detractors and skeptics conclude that a weak case can be made for sympathectomy for ischemic rest pain when arterial surgery is impractical, but there is no reliable evidence to support its use in intermittent claudication [21]. An additional limitation is that assessment of response to lumbar sympathectomy is difficult because selection of cases is usually empirical as ischemia is difficult to quantitate objectively. Different expectations in different patient groups and continuation of precipitating factors like smoking further compound the issue, thereby illustrating the pitfalls of applying physiological data to such a variability of pathological processes. This makes comparison between different reported series very difficult.
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