Chronic Refractory Angina

STELLATE GANGLION BLOCK FOR THE TREATMENT OF REFRACTORY ANGINA

Treatment aim

To improve the quality of life through the alleviation of symptoms.

Introduction

Stellate ganglion block (SGB) is a technique that has been used widely by pain specialists for treating chronic pain syndromes for many years(1). It also has other reported uses in quinine poisoning(2), the long QT syndrome(3), chest pain associated with primary pulmonary hypertension(4) and climacteric psychosis(5). It was recognised by neurosurgeons who performed destructive sympathectomies in the 1930's, that infiltration around the stellate ganglion with local anaesthetic prior to surgery was effective in alleviating angina for longer then the duration of the procaine(6). Wiener et al performed a small placebo controlled randomised trial of any intervention in angina in 1966 and showed that SGB is effective in reducing symptoms(7). We have confirmed the benefits of stellate ganglion block in over 54 consecutive patients(8) and have embarked on a large scale randomised double blind placebo controlled trial funded by the British Heart Foundation.

Theoretical considerations

The pathogenesis of angina and myocardial infarction pain involves the activation of the afferent sympathetic pathway. A frequent and important consequence of pain (especially when severe) is the flight or fight response through activation of sympathetic efferents. The clinical image of the patient with an acute myocardial infarction: cold, clammy, sweaty, anxious with a tachycardia: is secondary to this adrenergic activation. Therefore, angina might be seen as the sensory component of a positive feedback loop.

The angina relieving effects of sympathetic blockade might be due to interference with this maladaptive feedback loop, much in the same way as adenosine interrupts a re-entrant tachycardia. If such a loop exists, it may partly explain chronic refractory angina and the fact that temporary interruption of this pathway has a prolonged effect on pain(8).

Procedure

Our technique of stellate ganglion block is different to those previously described (1,9,10,11).

Patients are asked to have a light, early breakfast and then to remain fasted until they have been treated.

Written informed consent is obtained and a peripheral cannula is sited to ensure there is intravenous access. Early operators recommended lying patients flat. Many patients with advanced coronary artery disease have impaired left ventricular function and find lying flat uncomfortable, therefore in our practice the patient reclines to 20-30 with a pillow behind their head in the central “sniff the morning air” position. The mouth is open slightly to prevent swallowing and possible pharyngeal or oesophageal trauma. Throughout the procedure the patient is attached to a pulse oximeter and a Holter monitor, a full resuscitation trolley is close at hand and there are always two qualified medical practitioners trained in advanced cardiac life support present.

The needle is connected to a 20ml syringe via manometer tubing to permit easier control of the injection. The neck is prepared with cleaning solution. Then the cricoid cartilage is palpated with the middle finger of the non-dominant hand. This is then moved laterally to feel the bony prominence of the C6 transverse process. With this technique the carotid artery can be palpated and retracted laterally. Whilst maintaining pressure, a 21g needle is inserted into the neck over the middle finger. Once the needle is felt to be in gentle contact with bone, the middle finger is removed to allow the tissues to settle. Following negative aspiration, 15mls of plain 0.5% bupivacaine are injected, with repeated check aspirations every 3-4mls. The needle is then withdrawn and moderate pressure is applied. If blood is aspirated, then the needle should be removed and repositioned.

The patient then sits up so he/she is more comfortable and observed for 10 minutes. During this time, a Horner's syndrome frequently develops and Guttman's sign becomes positive. (see figure three) Frequently the patient also feels some warmth in the side of his/her face.

Patients are allowed home later the same day after they have eaten. Should they wish to drive themselves home, this is only permitted if they have been treated at least four hours previously and their vision is not impaired by a Horner's syndrome.

Treatment of patients who are anticoagulated

There is a group of patients with ischaemic heart disease who are anticoagulated, either because of atrial fibrillation or following valve replacement. We recommend that patients stop their warfarin for the three days prior to the procedure as long as they do not have a metal valve replacement. As long as their INR is lower than 1.5, stellate ganglion block is performed in the same way, except a 23g needle is substituted for the 21g needle.

For patients who are cannot have warfarin stopped, they must be admitted and temporarily switched to intravenous heparin. This is stopped for one hour prior to the stellate block.

Extent of spread

Different blocks in the same patient can produce varying amounts of spread(11) Studies using MRI(12) or CT(13) scanning have failed to demonstrate any evidence of spread to the stellate ganglion itself, although in the CT study the stellate ganglion could not be actually visualised. However an ultrasound imaging study(15) showed spread from C4 to C7 whilst using 5mls of local anaesthetic and what they considered to be an effective clinical stellate ganglion block in 23 out of 24 cases. Again the stellate ganglion could not actually be seen. Guntamukkala16 performed a cadaveric study using methylene blue and observed spread to T4 in most cases.

Repeatability

This procedure can be repeated many times. In one study a patient underwent stellate ganglion block (for none cardiac pain) on 132 consecutive days(17).

In our experience, beneficial amelioration of angina can be achieved with repeated blocks(8). There does not appear to be any predictability in the length of time a patient remains pain-free after successive blocks.

Complications

Stellate ganglion block is a safe procedure with a complication rate of 1.7/1000 reported by Wulf(18) In their series of approximately 45000 procedures, there were no deaths. The majority of complications are minor and short-lived. There are occasional reports of deaths associated with stellate ganglion block, the last being in 1952(1) however, resuscitation techniques have improved greatly since then.

The stellate ganglion is often very close to the vertebral artery and so care must be taken when positioning the needle as injection of local anaesthetic into the vascular system can precipitate convulsions. Spread of injectate into the epidural space can result in hypotension and bradycardia and there is also a risk of subarachnoid injection and total spinal block. Pneumothorax is uncommon but there is an increased chance when performing a C7 block. Associated brachial plexus block is seen in up to 10% of patients. As with all local anaesthetic patients can develop an allergic reaction, which may be serious: however this is very rare particularly when using amide local anaesthetics.

The recurrent laryngeal nerve lies medially to the sympathetic chain and slightly anterior to it. As local anaesthetic spreads, this may also be blocked resulting in a hoarse voice and a unilateral vocal cord paresis. The probability of this occurring has been demonstrated as 10% when using 10mls of local anaesthetic, rising to 80% when 20mls of bupivacaine was used.19 In our experience of more than 600 procedures(8) bilateral recurrent laryngeal nerve palsy has not occurred.

The development of a Horner's syndrome is usually taken as being demonstrative of an accurate stellate ganglion block(20). This is not normally troublesome although there have been case reports of it occurring bilaterally(21) which obviously may cause visual impairment.

Systemic drug toxicity is uncommon when using low dose local anaesthetic, however patients should be carefully observed for at least an hour post procedure. In a study by Hardy, mean peak levels of bupivacaine were achieved at 20 minutes post procedure and in no patient were toxic levels obtained(22).

We agree with Titley and Collins,23 that although the precautions we take will not prevent a serious complication, every opportunity should be taken to minimise potential risks, hence our protocol.

Nursing guidelines

The major central nervous system complications tend to occur during injection or shortly afterwards. Therefore we observe patients in a fully equipped resuscitation area for at least 15 minutes prior to them returning to their bed. Thereafter, the patient is monitored by qualified nursing staff who record the pulse and blood pressure every 15 minutes for the first hour and then every 30 minutes for the next four hours.

Due to the risk of recurrent laryngeal nerve palsy, the patient is allowed sips of water only for 30 minutes after the procedure. If tracheal irritation does not occur, the patient can eat and drink normally after this time. If there is any evidence of irritation, then the patient is allowed sips of water only until their voice returns to normal or it is 4 hours post block. An ECG is performed within the first hour.

Summary

Stellate ganglion block with local anaesthetic is a safe procedure. It has many uses in the treatment of chronic pain states(17) and we believe it has an important role in the management of refractory angina(24). A double blind, randomised placebo controlled study is underway at present to confirm this role funded by the British Heart Foundation.

If SGB fails

References

1. Moore DC. Stellate ganglion block. CC Thomas, Springfield Illinois. 1954.

2. Thomas D. Forced acid diuresis and stellate ganglion block in the treatment of quinine poisoning. Anaesthesia 1984;39:257-60.

3. Moss AJ and MacDonald J. Unilateral cervico-thoracic sympathetic ganglionectomy for the treatment of long QT interval syndrome. New Eng J Med 1971;285:903-4.

4. Parris WCV, Lin S, Frist W. Use of stellate ganglion blocks for chronic chest pain associated with primary pulmonary hypertension. Anesth Analg 1988;67:993-5

5. Ikeda K, Isshiki A, Yoshimatsu N, Oumi A, Ito S, Ikeda T. Three case reports of the use of stellate ganglion block for the climacteric psychosis. Masui 1993;42:1696-8.

6. Gask GE. The surgery of the sympathetic nervous system. British Journal of Surgery 1933;21:113-30.

7. Wiener L and Cox JW. Influence of stellate ganglion blockade on angina pectoris and the post exercise electrocardiogram. The American Journal of the Medical Sciences 1966;252:289-95.

8. Hammond C, Leach AA, Chester MR. Temporary sympathectomy in refractory angina. Heart 1999; 81(suppl):56.

9. Bryce-Smith R. Stellate ganglion block. Anaesthesia 1952;7:154-6.

10. Carron H and Litwiller R. Stellate Ganglion Block. Anaesthesia and analgesia 1975;54:567-70.

11. Davies RM. Stellate ganglion block – a new approach. Anaesthesia 1952;7:151-3.

12. Hogan QH et al. Success rates in producing sympathetic blockade by paratracheal injection. Clinical Journal of Pain 1994;10;139-45.

13. Hogan QH, Erickson SJ, Haddox JD, Abram SE. The spread of solutions during stellate ganglion block. Regional anaesthesia 1992;17:78-83.

14. Christie JM, Martinez CR. Computerized axial tomography to define the distribution of solution after stellate ganglion nerve block. Journal of Clinical Anaesthesia 1995;7:306-11.

15. Kapral S, Krafft P, Gosch M, Fleischmann D, Weinstabl C. Ultrasound imaging for stellate ganglion block: direct visualisation of puncture site and local anaesthetic spread. Regional anaesthesia 1995;20:323-8.

16. Guntamukkala M, Hardy PAJ. Spread of injectate after stellate ganglion block in man: an anatomical study. British Journal of Anaesthesia 1991;66:643-4.

17. Higa K, Dan K, Monabe H, Noda B. Factors influencing the duration of treatment of acute herpetic pain with sympathetic nerve block: importance of severity of herpes zoster assessed by the maximum antibody titers to varicella-zoster virus in otherwise healthy patients. Pain 1988;32:147-57.

18. Wulf H, Maier CH. Complications of stellate ganglion blockade: results of a survey. Anaesthetist 1992;41:146-51.

19. Hardy PAJ, Wells JCD. Extent of sympathetic blockade after stellate ganglion block with bupivacaine. Pain 1989;36:193-6.

20. Malmqvist EL, Bengtsson M, SorensenJ. Efficacy of stellate ganglion block: a clinical study with bupivacaine. Regional Anesthesia 1992;17:340-7.

21. Wallace MS, Milholland AV. Contralateral spread of local anaesthetic with stellate ganglion block. Regional Anesthesia 1993;18:55-9.

22. Hardy PAJ, Williams NE. Plasma concentrations of bupivacaine after stellate ganglion block using two volumes of 0.25% bupivacaine plain solution. British Journal of Anaesthesia 1990;65:243-4.

23. Titley G, Collins PD. Stellate ganglion blockade: clinics take precautions, but follow few guidelines. BMJ 1998;317:753. (letter)

24. Chester MR, Hammond C,  Leach A. Long term benefits of stellate ganglion block on severe chronic refractory angina. Pain 2000 (in press)

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