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Mononeuritis multiplex
Mononeuritis multiplex A complication of open-heart surgery A prospective examination of all patients undergoing cardiopulmonary bypass in one unit revealed that a number of peripheral nerve lesions occurred during the postoperative period. These were documented over a period of 20 months with follow-up of those patients so affected.
J. R. W. Keates, F.R.C.S.,* D. M. Innocenti, M.S.C.P., and D. N. Ross, F.R.C.S., London, England
JLhysicians generally accept the fact that commonly used techniques of cardiopulmonary bypass damage the blood constituents and have a deleterious effect on all organs in the body. Many patients undergoing open-heart operations show some evidence of temporary central nervous system dysfunction in the immediate postoperative period, and the incidence is generally directly proportional to the length of time of perfusion. Fortunately, in most cases, no residual neurologic deficit persists. However, there have been a number of reports on the incidence and pathology of permanent brain damage after such operations.1 ' In addition to the central nervous system effects, which may be localized or generalized, peripheral neurologic defects have been noticed at this institution. These lesions fitted the clinical description of mononeuritis multiplex. In an attempt to delineate the problem, we instituted a prospective clinical investigation. Materials and methods All patients undergoing open-heart surgery at Guy's Hospital between April 1, From The Thoracic Unit and Department of Physiotherapy, Guy's Hospital, London SE1, England. Received for publication Aug. 28, 1974. •Present address: Cardiothoracic Department, St. Thomas' Hospital, London SE1, England.
8 16
1972, and Dec. 31, 1973, were included in this investigation. Each patient was subjected to a neurologic assessment preoperatively with particular emphasis on peripheral nerve function. A few patients were taken to the operating room too quickly to enable this to be done, but none of these patients developed lesions. Postoperatively, as soon as the patients regained consciousness, their conditions were reassessed. Any neurologic deficit observed was followed until it resolved. Patients excluded from this assessment include all those who died without regaining consciousness and those in whom there was a serious central nervous lesion which did not allow accurate assessment of peripheral nerve function. The diagnosis of mononeuritis was made on the clinical demonstration of partial or complete loss of motor and/or sensory function over the area of distribution of a peripheral nerve. The fifth, seventh, ninth, tenth, and eleventh cranial nerves were considered to be peripheral nerves for the purpose of this investigation. The 529 patients were from 21 months to 74 years of age, with a mean of 41.5 years. Two types of perfusion techniques were used: (1) the Bentley Temptrol Model Q 100 oxygenator, with Hartmann's solution
Volume 69
Mononeuritis multiplex
Number 5
8 17
May, 1975
Table I Perfusion Patient Name Age
Date of operation
Operation
Time fmin.)
Type
Neurologic lesion
101
1 -
74
2-
Left posterior interosseous nerve a. Right anterior tibial nerve
B. M.
50
ApriU, 1972
CABG (2)
D. T.
33
April 28, 1972
AVR
G. A.
68
May 9, 1972
CABG (2)
104
1-
V. B. M. G.
54 39
May 31, 1972 June20, 1972
AVR AVR, PA
68 122
2 1
R. R. L. B.
51 47 48 62
Sept. 19, 1972 Oct. 10, 1972 Dec. 15, 1972 Jan. 20, 1973
CABG(2) MVR(reop.) MVR, TA MVR TVR
49 112 62 103
1 1 2 2
L. A.
30
Feb. 2, 1973
Fallot repair
137
G. H.
60
April 3, 1973
CABG (2)
142
1+
HE. A. G.
56 33
Oct. 9, 1973 Oct. 16, 1973
CABG (3) MVR(reop.)
78 66
2+ 1+
M.S.
51
Dec.21,1973
AVR(reop.)
87
2+
H. W. L. J.
Recovery and comments Full at 6 months
a. Full motor function at 3 months; partial sensory function after 16 months b. Left recurrent laryngeal b. Full after 5 weeks nerve Full at 6 weeks (previous Left facial nerve history, see text) Right ulnar nerve Full at 6 months Left deep branch of ulnar Full at 2 months nerve Left ulnar nerve Full at 3 months Right suprascapular nerve Full at 3 weeks Right circumflex nerve Full at 2 months a. Right anterior tibial a. Full at 3 months nerve b. Left recurrent laryngeal b. Full at 5 months nerve Left circumflex nerve Complicated by a "frozen shoulder"; recovery 90 percent at 8 months, 100 percent at 18 months Right greater occipital Full at 3 weeks nerve Right ulnar nerve Full at 2 weeks Right ulnar nerve Full at 3 weeks (previous history, see text) Right lateral cutaneous Full at 3 months nerve of forearm
Legend: CABG, Coronary artery bypass graft. AVR, Aortic valve replacement. PA, Pulmonary autograft. MVR, Mitral valve replacement. TA, Tricuspid annuloplasty. TVR, Tricuspid valve replacement. - Indicates filters were not used. + Indicates filters were used. For perfusion techniques 1 and 2, see text.
Table II Age(yr.)
No filter Filters used
Perfusion time (min.)
Whole group
Patients with lesions
Whole group
Patients with lesions
41.4 ±16.4 41.7 ±16.6
48.2 ±11.9 50.0 ±11.9
85.0 ±44.8 89.0 ±44.8
93.2 ±28.4 93.3 ±33.6
and 1 unit of stored blood as the prime; (2) the Travenol Model 6 LF oxygenator, with Hartmann's solution in 5 per cent dextrose as the prime. There were 229 patients in the first group and 300 in the second group. In the last 260 patients, blood filters were used in the cardiotomy
reservoir and (in technique 2 only) in the arterial line. Electromyography was not employed routinely. However, in the case in which it was employed (Patient L. A.), the electrical activity was characteristic of severe denervation with evidence of progressive recovery. Neither conduction studies nor nerve biopsies were performed. The clinical picture of functional loss over the distribution of a peripheral nerve was taken as pathognomic of mononeuritis multiplex. Results Between April 1, 1972, and Dec. 31, 1973, 529 patients underwent operations. Fourteen of them developed peripheral
The Journal of
8 18
Keates, Innocenti,
Ross
Thoracic and Cardiovascular Surgery
neurologic lesions. Details of these patients are shown in Table I. The differences in average ages and average perfusion times between the two groups were not significant (Table II); thus the patients and operative procedures in the two groups were comparable. The incidences of lesions in the patients with varying oxygenators, pump primes, and surgical teams were almost equal. Blood filtration made no significant difference in the incidence of lesions. No affected patient had diabetes. The nerve lesions observed showed no particular pattern except that upper limb lesions were more common than lower limb lesions (10 and 2, respectively). Two patients had two nerves affected and none had more than two. Cranial nerves were affected in 3 patients. Of the sixteen nerves damaged, fifteen recovered fully within 6 months. In the sixteenth case, which was complicated by a "frozen shoulder," full recovery took 18 months. Several of these lesions were not noticed by the patient for some time after the operation and would probably not have been diagnosed except for the systematic postoperative assessment that we were using for this investigation. The degree of loss of function of a given nerve was quite variable. The length of time required for full return of function varied from 2 to 6 months, with an average of 11 weeks, and was related to the extent of loss of function; the most severely affected nerves took the longest time to recover. In assessing progress, we considered motor nerve function to be the prime index of recovery. Full sensory recovery took longer and was incomplete in 1 patient. All patients had supportive physiotherapy during the period of recovery. In 2 cases, lesions of the affected nerve had been sustained previously and had completely resolved, only to recur temporarily after the operation. Patient (G. A.) had had an accident 52 years earlier, after which he was left with peripheral left facial palsy. This resolved over a period of about 2 months. Following the coronary artery graft
operation, the facial palsy recurred and took 6 weeks to resolve. In another case (Patient A. G.), the patient had undergone mitral valve replacement with a mounted fascia lata valve in 1969. This was followed by weakness in the right forearm and partial loss of sensation along the ulnar border of that arm, but the problem resolved over a period of weeks. After the second operation to replace this valve 4 years later, the symptoms and signs recurred and took 3 weeks to resolve fully. Discussion Despite the multiplicity of reports in the literature on central nervous damage following cardiopulmonary bypass, we have been able to find very little data on peripheral nerve lesions. One report5 described a single case of mononeuritis multiplex complicating the postperfusion syndrome which was attributed to an infectious agent. Our series was originally started to demonstrate whether isolated peripheral nerve lesions, which had been noticed sporadically on this and other units, were occurring on a regular basis and, if they were, to determine their natural history. We have shown in the first group that the incidence was approximately 1 in 27 cases. This was a surprisingly high frequency, and it was clear that in the past many of the lesions had been missed or attributed to central nervous pathology. The lesions showed some predilection for the upper half of the body, although the numbers involved are too small for any definite conclusion to be made. Just as resolved central nervous lesions recur after cardiopulmonary bypass, so in 2 cases previous peripheral lesions were reawakened after intervals of 52 and 4 years. The resolution of the lesions follows a slow but progressive course with complete or almost complete recovery as the rule. We have found this fact helpful in reassuring our patients. The time course is very similar to that in Parks' 0 series of postoperative nerve damage following miscellaneous operations. Mononeuritis or mononeuritis multiplex
Volume 69
Mononeuritis multiplex
Number 5
8 19
May, 1975
is the loss of function of a peripheral nerve or nerves due to compression or ischemia. The ischemia may be due to peripheral vascular disease or to a diffuse inflammatory disease of arteries such as polyarteritis nodosa. In the latter case, arteritis of the vasa nervorum produces the nervous lesions, presumably by ischemia.7 The peripheral nerves are well supplied by blood vessels, and interference with any one source of supply is unlikely to cause serious interruption of the circulation of the nerve.s However, emboli were postulated as the cause of mononeuropathy in 5 cases of active endocarditis reported by Royden Jones.11 Peripheral neuropathies occur after many types of operations due to injury under anesthesia, but the incidence is difficult to ascertain. The largest series show an incidence of 72 out of 50,000 operations" and 31 out of 30,000 procedures.1" Most authors stress that the primary cause is prolonged malposition on the operating table. Another contributory cause was found to be pre-existing disease, especially atherosclerosis and diabetes. In this series the possible role of microemboli was not confirmed by a reduction in the incidence in those perfusions with blood nitration. We believe that the etiology is probably multiple, including local pressure and abnormal perfusion. Conclusion Mononeuritis multiplex has been documented as a complication of cardiopulmo-
nary bypass in a prospective clinical examination. The incidence was higher than was previously realized and the etiology is unknown. The prognosis is good. We would like to thank A. K. Yates for permission to study his patients and Miss Anne Long for typing the manuscript. REFERENCES 1 Javid, H., Tufo, H. M., Najafi, H., Dye, W. S., Hunter, J. A., and Julian, O. C : Neurological Abnormalities Following Open-Heart Surgery
2
3
4
5
6 7
8
9
10
J.
THORAC.
CARDIOVASC.
SURG.
58:
502, 1969. Brierly, J. B.: Brain Damage Complicating Open Heart Surgery: A Neuropathological Study of 46 Patients, Proc. R. Soc. Med. 60: 858, 1967. Gilman, S.: Cerebral Disorders After OpenHeart Operations, N. Engl. J. Med. 272: 489, 1965. Branthwaite, M. A.: Detection of Neurological Damage During Open-Heart Surgery, Thorax 28: 464, 1973. Walsh, J. C : Mononeuritis Multiplex Complicating the post-perfusion Syndrome, Aust. Ann. Med. 17: 327, 1968. Parks, B. J.: Postoperative Peripheral Neuropathies, Surgery 74: 348, 1973. Brain, Lord Walton J. N.: Brain's Diseases of the Nervous System, ed. 7, London, 1969, Oxford University Press. Richards, R. L.: Ischaemic Lesions of Peripheral Nerves: A Review, J. Neurol. Neurosurg. Psychiatry 19: 76, 1951. Royden Jones, H., and Siekert, R. G.: Embolic Mononeuropathy and Bacterial Endocarditis, Arch. Neurol. 19: 535, 1968. Dhuner, K. G.: Nerve Injuries Following Operations: A Survey of Cases Occurring During a Six-Year Period, Anesthesiology 11: 289, 1948.
J. R. W. Keates, F.R.C.S.,* D. M. Innocenti, M.S.C.P., and D. N. Ross, F.R.C.S., London, England
JLhysicians generally accept the fact that commonly used techniques of cardiopulmonary bypass damage the blood constituents and have a deleterious effect on all organs in the body. Many patients undergoing open-heart operations show some evidence of temporary central nervous system dysfunction in the immediate postoperative period, and the incidence is generally directly proportional to the length of time of perfusion. Fortunately, in most cases, no residual neurologic deficit persists. However, there have been a number of reports on the incidence and pathology of permanent brain damage after such operations.1 ' In addition to the central nervous system effects, which may be localized or generalized, peripheral neurologic defects have been noticed at this institution. These lesions fitted the clinical description of mononeuritis multiplex. In an attempt to delineate the problem, we instituted a prospective clinical investigation. Materials and methods All patients undergoing open-heart surgery at Guy's Hospital between April 1, From The Thoracic Unit and Department of Physiotherapy, Guy's Hospital, London SE1, England. Received for publication Aug. 28, 1974. •Present address: Cardiothoracic Department, St. Thomas' Hospital, London SE1, England.
8 16
1972, and Dec. 31, 1973, were included in this investigation. Each patient was subjected to a neurologic assessment preoperatively with particular emphasis on peripheral nerve function. A few patients were taken to the operating room too quickly to enable this to be done, but none of these patients developed lesions. Postoperatively, as soon as the patients regained consciousness, their conditions were reassessed. Any neurologic deficit observed was followed until it resolved. Patients excluded from this assessment include all those who died without regaining consciousness and those in whom there was a serious central nervous lesion which did not allow accurate assessment of peripheral nerve function. The diagnosis of mononeuritis was made on the clinical demonstration of partial or complete loss of motor and/or sensory function over the area of distribution of a peripheral nerve. The fifth, seventh, ninth, tenth, and eleventh cranial nerves were considered to be peripheral nerves for the purpose of this investigation. The 529 patients were from 21 months to 74 years of age, with a mean of 41.5 years. Two types of perfusion techniques were used: (1) the Bentley Temptrol Model Q 100 oxygenator, with Hartmann's solution
Volume 69
Mononeuritis multiplex
Number 5
8 17
May, 1975
Table I Perfusion Patient Name Age
Date of operation
Operation
Time fmin.)
Type
Neurologic lesion
101
1 -
74
2-
Left posterior interosseous nerve a. Right anterior tibial nerve
B. M.
50
ApriU, 1972
CABG (2)
D. T.
33
April 28, 1972
AVR
G. A.
68
May 9, 1972
CABG (2)
104
1-
V. B. M. G.
54 39
May 31, 1972 June20, 1972
AVR AVR, PA
68 122
2 1
R. R. L. B.
51 47 48 62
Sept. 19, 1972 Oct. 10, 1972 Dec. 15, 1972 Jan. 20, 1973
CABG(2) MVR(reop.) MVR, TA MVR TVR
49 112 62 103
1 1 2 2
L. A.
30
Feb. 2, 1973
Fallot repair
137
G. H.
60
April 3, 1973
CABG (2)
142
1+
HE. A. G.
56 33
Oct. 9, 1973 Oct. 16, 1973
CABG (3) MVR(reop.)
78 66
2+ 1+
M.S.
51
Dec.21,1973
AVR(reop.)
87
2+
H. W. L. J.
Recovery and comments Full at 6 months
a. Full motor function at 3 months; partial sensory function after 16 months b. Left recurrent laryngeal b. Full after 5 weeks nerve Full at 6 weeks (previous Left facial nerve history, see text) Right ulnar nerve Full at 6 months Left deep branch of ulnar Full at 2 months nerve Left ulnar nerve Full at 3 months Right suprascapular nerve Full at 3 weeks Right circumflex nerve Full at 2 months a. Right anterior tibial a. Full at 3 months nerve b. Left recurrent laryngeal b. Full at 5 months nerve Left circumflex nerve Complicated by a "frozen shoulder"; recovery 90 percent at 8 months, 100 percent at 18 months Right greater occipital Full at 3 weeks nerve Right ulnar nerve Full at 2 weeks Right ulnar nerve Full at 3 weeks (previous history, see text) Right lateral cutaneous Full at 3 months nerve of forearm
Legend: CABG, Coronary artery bypass graft. AVR, Aortic valve replacement. PA, Pulmonary autograft. MVR, Mitral valve replacement. TA, Tricuspid annuloplasty. TVR, Tricuspid valve replacement. - Indicates filters were not used. + Indicates filters were used. For perfusion techniques 1 and 2, see text.
Table II Age(yr.)
No filter Filters used
Perfusion time (min.)
Whole group
Patients with lesions
Whole group
Patients with lesions
41.4 ±16.4 41.7 ±16.6
48.2 ±11.9 50.0 ±11.9
85.0 ±44.8 89.0 ±44.8
93.2 ±28.4 93.3 ±33.6
and 1 unit of stored blood as the prime; (2) the Travenol Model 6 LF oxygenator, with Hartmann's solution in 5 per cent dextrose as the prime. There were 229 patients in the first group and 300 in the second group. In the last 260 patients, blood filters were used in the cardiotomy
reservoir and (in technique 2 only) in the arterial line. Electromyography was not employed routinely. However, in the case in which it was employed (Patient L. A.), the electrical activity was characteristic of severe denervation with evidence of progressive recovery. Neither conduction studies nor nerve biopsies were performed. The clinical picture of functional loss over the distribution of a peripheral nerve was taken as pathognomic of mononeuritis multiplex. Results Between April 1, 1972, and Dec. 31, 1973, 529 patients underwent operations. Fourteen of them developed peripheral
The Journal of
8 18
Keates, Innocenti,
Ross
Thoracic and Cardiovascular Surgery
neurologic lesions. Details of these patients are shown in Table I. The differences in average ages and average perfusion times between the two groups were not significant (Table II); thus the patients and operative procedures in the two groups were comparable. The incidences of lesions in the patients with varying oxygenators, pump primes, and surgical teams were almost equal. Blood filtration made no significant difference in the incidence of lesions. No affected patient had diabetes. The nerve lesions observed showed no particular pattern except that upper limb lesions were more common than lower limb lesions (10 and 2, respectively). Two patients had two nerves affected and none had more than two. Cranial nerves were affected in 3 patients. Of the sixteen nerves damaged, fifteen recovered fully within 6 months. In the sixteenth case, which was complicated by a "frozen shoulder," full recovery took 18 months. Several of these lesions were not noticed by the patient for some time after the operation and would probably not have been diagnosed except for the systematic postoperative assessment that we were using for this investigation. The degree of loss of function of a given nerve was quite variable. The length of time required for full return of function varied from 2 to 6 months, with an average of 11 weeks, and was related to the extent of loss of function; the most severely affected nerves took the longest time to recover. In assessing progress, we considered motor nerve function to be the prime index of recovery. Full sensory recovery took longer and was incomplete in 1 patient. All patients had supportive physiotherapy during the period of recovery. In 2 cases, lesions of the affected nerve had been sustained previously and had completely resolved, only to recur temporarily after the operation. Patient (G. A.) had had an accident 52 years earlier, after which he was left with peripheral left facial palsy. This resolved over a period of about 2 months. Following the coronary artery graft
operation, the facial palsy recurred and took 6 weeks to resolve. In another case (Patient A. G.), the patient had undergone mitral valve replacement with a mounted fascia lata valve in 1969. This was followed by weakness in the right forearm and partial loss of sensation along the ulnar border of that arm, but the problem resolved over a period of weeks. After the second operation to replace this valve 4 years later, the symptoms and signs recurred and took 3 weeks to resolve fully. Discussion Despite the multiplicity of reports in the literature on central nervous damage following cardiopulmonary bypass, we have been able to find very little data on peripheral nerve lesions. One report5 described a single case of mononeuritis multiplex complicating the postperfusion syndrome which was attributed to an infectious agent. Our series was originally started to demonstrate whether isolated peripheral nerve lesions, which had been noticed sporadically on this and other units, were occurring on a regular basis and, if they were, to determine their natural history. We have shown in the first group that the incidence was approximately 1 in 27 cases. This was a surprisingly high frequency, and it was clear that in the past many of the lesions had been missed or attributed to central nervous pathology. The lesions showed some predilection for the upper half of the body, although the numbers involved are too small for any definite conclusion to be made. Just as resolved central nervous lesions recur after cardiopulmonary bypass, so in 2 cases previous peripheral lesions were reawakened after intervals of 52 and 4 years. The resolution of the lesions follows a slow but progressive course with complete or almost complete recovery as the rule. We have found this fact helpful in reassuring our patients. The time course is very similar to that in Parks' 0 series of postoperative nerve damage following miscellaneous operations. Mononeuritis or mononeuritis multiplex
Volume 69
Mononeuritis multiplex
Number 5
8 19
May, 1975
is the loss of function of a peripheral nerve or nerves due to compression or ischemia. The ischemia may be due to peripheral vascular disease or to a diffuse inflammatory disease of arteries such as polyarteritis nodosa. In the latter case, arteritis of the vasa nervorum produces the nervous lesions, presumably by ischemia.7 The peripheral nerves are well supplied by blood vessels, and interference with any one source of supply is unlikely to cause serious interruption of the circulation of the nerve.s However, emboli were postulated as the cause of mononeuropathy in 5 cases of active endocarditis reported by Royden Jones.11 Peripheral neuropathies occur after many types of operations due to injury under anesthesia, but the incidence is difficult to ascertain. The largest series show an incidence of 72 out of 50,000 operations" and 31 out of 30,000 procedures.1" Most authors stress that the primary cause is prolonged malposition on the operating table. Another contributory cause was found to be pre-existing disease, especially atherosclerosis and diabetes. In this series the possible role of microemboli was not confirmed by a reduction in the incidence in those perfusions with blood nitration. We believe that the etiology is probably multiple, including local pressure and abnormal perfusion. Conclusion Mononeuritis multiplex has been documented as a complication of cardiopulmo-
nary bypass in a prospective clinical examination. The incidence was higher than was previously realized and the etiology is unknown. The prognosis is good. We would like to thank A. K. Yates for permission to study his patients and Miss Anne Long for typing the manuscript. REFERENCES 1 Javid, H., Tufo, H. M., Najafi, H., Dye, W. S., Hunter, J. A., and Julian, O. C : Neurological Abnormalities Following Open-Heart Surgery
2
3
4
5
6 7
8
9
10
J.
THORAC.
CARDIOVASC.
SURG.
58:
502, 1969. Brierly, J. B.: Brain Damage Complicating Open Heart Surgery: A Neuropathological Study of 46 Patients, Proc. R. Soc. Med. 60: 858, 1967. Gilman, S.: Cerebral Disorders After OpenHeart Operations, N. Engl. J. Med. 272: 489, 1965. Branthwaite, M. A.: Detection of Neurological Damage During Open-Heart Surgery, Thorax 28: 464, 1973. Walsh, J. C : Mononeuritis Multiplex Complicating the post-perfusion Syndrome, Aust. Ann. Med. 17: 327, 1968. Parks, B. J.: Postoperative Peripheral Neuropathies, Surgery 74: 348, 1973. Brain, Lord Walton J. N.: Brain's Diseases of the Nervous System, ed. 7, London, 1969, Oxford University Press. Richards, R. L.: Ischaemic Lesions of Peripheral Nerves: A Review, J. Neurol. Neurosurg. Psychiatry 19: 76, 1951. Royden Jones, H., and Siekert, R. G.: Embolic Mononeuropathy and Bacterial Endocarditis, Arch. Neurol. 19: 535, 1968. Dhuner, K. G.: Nerve Injuries Following Operations: A Survey of Cases Occurring During a Six-Year Period, Anesthesiology 11: 289, 1948.