Prognosis of intraoperative brachial plexus injury: a review of 22... B. B -D S. S
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Prognosis of intraoperative brachial plexus injury: a review of 22... B. B -D S. S
British Journal of Anaesthesia 1997; 79: 440–445 Prognosis of intraoperative brachial plexus injury: a review of 22 cases B. BEN-DAVID AND S. STAHL Summary A retrospective review over 6 yr of patients presenting to the hand clinic was performed to identify cases of postoperative brachial plexopathy (PBP) and to assess both prognosis and early indices of prognosis. Over this period (1989–1995), 22 patients were referred by the hospital’s surgical departments to the hand clinic because of PBP. Eight cases followed open heart surgery (OHS) and 14 followed non-cardiac surgery (NCS). Median full recovery took 10 (range 4–16) weeks and 20 (8–50) weeks, respectively. Long-term follow-up revealed one OHS patient with residual tingling and three NCS patients with residual weakness. Brachial plexopathy after median sternotomy was characterized by a predominance of sensory complaint in the lower roots of the plexus. Injury after non-cardiac surgery was reflected by a predominance of motor deficit in the upper and middle roots. Brachial plexus injury after cardiac surgery carries an excellent prognosis for full functional recovery. Although the limited number of cases precludes statistical substantiation, the data suggest that the prognosis of PBP after noncardiac surgery may be worse in males, diabetics, those with injury to all roots of the plexus and, when in addition to the motor deficit there is sensory loss and pain or dysaesthesia. At a 1 week “prognostic milestone”, 79% of NCS patients with significant symptomatology enjoyed complete recovery although this took as long as 5 months to 1 yr in 50% of patients. At a 6–8 week “prognostic milestone”, 50% of those who had not yet had improvement in the motor deficit suffered residual neurological deficit. All patients recovered to a significant extent even when recovery was not complete and none suffered from late deterioration or chronic pain. (Br. J. Anaesth. 1997; 79: 440–445). Key words Complications, brachial plexus injury. Nerve, damage (postoperative). Postoperative brachial plexopathy (PBP) has been documented in the literature for more than 100 yr. PBP is generally believed to be a result of traction injury of the nerves with compression a contributing factor.1 Both stretching and compression of the nerve ultimately lead to ischaemia of the vasa nervorum and subsequent injury to the nerve.2–4 In addition, there may be rupture of intraneural capillaries and haematoma formation with further compression.1 Several factors have been associated with intraoperative brachial plexus injury, including concomitant patient disease, anatomical variations, positioning of the patient, surgical factors and physiological factors (table 1). The prevalence of PBP has been estimated at 0.02–0.06%.1 5 6 A recent review of 1541 closed anaesthesia malpractice claims included 227 (15%) for nerve injury. Of these, brachial plexus injury represented 23% and was second only to ulnar neuropathy (34%) in frequency.7 Insofar as these cases draw from insurance claim files, they almost certainly represent cases of residual loss and dysfunction. Yet previous authors have suggested that the long-term outcome in cases of intraoperative brachial plexus injury is almost invariably good—an apparent contradiction.1 8–10 Review of the literature regarding prognosis and outcome of PBP reveals a relatively sparse published data base.1 6 10 11 This is particularly true if one considers separately those cases occurring after non-cardiac surgery. It is reasonable to assume that an awareness of the potential for brachial plexus and other nerve injuries together with a knowledge of the pertinent anatomy, pathogenesis and associated risk factors should reduce the incidence of these injuries. However, this information is of little practical value when confronted with such a patient after operation. Foremost among the patient’s anxious questions will be with regard to prognosis. This retrospective review was undertaken in order to specifically address the question of prognosis of PBP. Patients and methods The records of the Rambam Medical Center Hand Clinic were searched for all cases of introperative brachial plexus injury occurring during the period 1989–1995. Both clinic and inpatient hospital charts were reviewed thoroughly and the patients, where possible, were contacted for long-term follow-up. All patients included in this review were those who presented after operation to the hand clinic following surgery at this institution. The data do not include BRUCE BEN-DAVID, MD, Department of Anesthesia, HerzliyaHaifa (Horev) Medical Center, 15 Horev Street, Haifa, Israel. SHALOM STAHL, MD, Hand Unit, Rambam Medical Center, Haifa, Israel. Accepted for publication: May 8, 1997. Correspondence to B. B.-D. Prognosis of intraoperative brachial plexus injury 441 Table 1 Factors associated with intraoperative brachial plexus injury Each patient’s injury was described by a specific description of the involved nerve roots and by a description of the initial presentation in terms of pain, motor and sensory impairment. For the purposes of this review these disturbances were classified on three-point scales. These scales were: motor: 1paralysis, 2paresis, 3no weakness; sensory: 1anaesthesia, 2hypoaesthesia, 3 normal sensation; and pain: 1 frank pain, 2 dysaesthesia, 3no pain. Electromyography (EMG) was not performed in the early postoperative period as this would only be indicated to validate suspicion of a pre-existing neurological condition.12 Electrophysiological studies were performed 6–8 weeks after operation, but only in those patients who had yet to demonstrate significant clinical improvement. The purpose of the study was to establish nerve continuity and to serve as a baseline for further evaluation and decision making regarding other intervention (e.g. surgical neurolysis). All patients were treated in a similar manner. To prevent contractures, occupational therapy was undertaken for splinting of the wrist and fingers where indicated. Weakness resulting in shoulder subluxation or difficulty in elbow flexion was treated with a supportive sling. Active and passive physical therapy was conducted agressively in all patients. Particular attention was paid to full passive range of motion exercises several times a day to maintain joint motion and prevent contractures. Concomitant disease Diabetes mellitus Hypothyroidsim Pernicious anaemia Alcoholism Pre-existing neuropathy Herpes zoster Polyarteritis nodosa Peripheral vascular disease Coagulopathy Concomitant anatomical predisposition Cervical rib Scalene muscle hypertrophy Deformity (e.g. post-traumatic) of shoulder region Anomalous derivation of plexus Positioning Steep Trendelenburg Steep Trendelenburgshoulder braces Steep Trendelenburgwrist suspension Excessive abduction of arm (990⬚) Dorsal extension at shoulder Posterior shoulder displacement External rotation of arm Excessive rotation of head Surgical Prolonged operative time Median sternotomy Physiological Hypothermia Hypotension those patients who had in-hospital consultations unless the patient went on to receive care through the outpatient hand clinic. No patient presented to the clinic sooner than 1 week after operation. Patients were seen at monthly intervals for 2–3 months after achieving maximum recovery. Longterm follow-up to verify residual injuries and to eliminate the possibility of late deterioration was provided by phone contact during the gathering of data for this review. Evaluation of all patients included a detailed history covering concomitant diseases and predisposing factors, a clinical history regarding upper extremity pain, paraesthesia, numbness and weakness, and physical examination of all motor and sensory functions supplied by the brachial plexus. Results A total of 22 cases of PBP were identified; 14 of these had undergone non-cardiac surgery (NCS) (table 2) and eight had undergone open heart surgery (OHS) with median sternotomy (table 3). In the NCS group there were six women and eight men, with mean ages of 52 and 57 yr, respectively. In the OHS group there were seven males (mean age 62 yr) and one female (aged 45 yr). Both groups had patients with possible contributing factors. Hospital inpatient chart reviews revealed that all patients had undergone general anaesthesia, but none of the charts contained information on the specifics of Table 2 Cases of postoperative bracial plexopathy following open heart surgery. Initial presentation: motor, 1paralysis, 2paresis, 3no weakness; sensory, 1anaesthesia, 2hypoaesthesia, 3normal sensation; pain, 1frank pain 2dysaesthesia, 3no pain. CABGcoronary artery bypass grafts, MVRmitral valve replacement Patient No. Possible Presented contributory Age Onset of to clinic pre-existing Sex (yr) Sx postop. (weeks) Surgery condition 1 4 7 14 M M M M 61 50 60 58 1 day Immediate 2 days 1 day 16 17 F M 45 58 1 day 2 Immediate 1.5 MVR CABG 20 21 M M 72 76 1 day 1 day CABG CABG 5 2 2 2 4 2 CABG CABG CABG CABG Injury Not Time to to improved max. recovery Degree of recovery Motor Sensory Pain roots at 6–8 wks (weeks) Initial presentation 2 3 2 Ulnar cubital 2 syndrome Cervical rib 3 History of 2 brachial plexus injury 3 Diabetes 3 2 3 2 2 3 2 3 1 C8–T1 C8–T1 C8–T1 C8–T1 13 wks 4 wks 8 wks 10 wks Full Full Full Full 1 1 2 1 C7–T1 C7–T1 16 wks 10 wks Full Full 2 2 3 2 C8–T1 C8–T1 7 wks 40 wks Full Residual tingling Full 10 C5–7 3 3 2 Residual weakness 32 2 2 2 54 2 days 3 F 22 3 1 day 38 M Road trauma pinning femur, tibia fxs, laparotomy Hysterectomy Carpal tunnel Thoracic outlet syndrome C5–8 24 48 26 C5–8 C5–T1 C7–T1 3 3 3 3 3 2 1 2 2 Immediate 1 1 day 4 2 days 1.5 55 48 55 F M M Shoulder replacement Nephrectomy Hemicolectomy 16 50 8 15 29 20 16 56 56 C6–8 C5–T1 C5–6 C5–7 C5–7 C5–8 C5–6 C5–T1 C5–7 3 1 3 3 2 3 3 1 2 2 2 3 3 2 3 3 2 2 2 2 2 2 2 2 2 2 2 Hysterectomy Diabetes Aorto-bifemoral Alcoholism Cholecystectomy Carpal tunnel Abd.-perineal resection Sigmoidectomy Aorto-bifemoral Heavy smoke rperiph. vasc. disease Road trauma laparotomy, splenectomy Hemicolectomy Pancreas transplant Diabetes 1 day 1 day 1 day Immediate Immediate 1 day 3 days 1 day 1 day 3 3 2 2 1 1 1 3 2 55 62 48 64 70 72 32 70 46 F M F M F M F M M Patient No. 2 3 5 6 8 9 10 11 12 loss 13 15 18 weeks) 19 Not improved at 6–8 wks Initial presentation Injury ---------------------------------------- to Motor Sensory Pain roots Possible contributory pre-existing condition Presented to clinic Age Onset of Sex (yr) Sx postop (weeks) Surgery Full Full Full (scalenectomy at 18 Table 3 Cases of postoperative brachial plexopathy following non-cardiac surgery. Initial presentation: motor, 1paralysis, 2paresis, 3no weakness; sensory, 1 anaesthesia, 2hypoaesthesia, 3 normal sensation; pain, 1frank pain 2dysaesthesia, 3no pain intraoperative positioning or arm positioning. None of the patients had undergone regional anaesthesia of the neck or upper extremity. All operations were of more than 2 h duration but there was no correlation between duration and long-term outcome. Because of the retrospective nature of the study and the limited method of case collection, no attempt was made to estimate incidence data from the total number of surgical cases over this period. In the OHS group, seven of eight patients achieved full recovery over a median of 10 (range 4–16) weeks. One patient, a diabetic, suffered from a persistent tingling sensation in the affected hand. All had suffered injury to the roots of the lower trunk (C8, T1) with two also having injury to the middle trunk (C7). In the NCS group, three of 14 patients failed to achieve full recovery although all patients improved substantially. Injuries included roots of upper and middle trunks in all but one patient (No. 18). Three patients (Nos 3, 11 and 15) had injury inclusive of all roots of the plexus. For patients who recovered fully, the median time to recovery was 20 (range 8–50) weeks after operation. Six patients had no evidence of motor improvement by 6–8 weeks after operation and were studied by EMG. This continued evaluation, and a prior history of thoracic outlet syndrome, led to scalenectomy in patient No. 18, the result of which was complete neurological recovery. Age had no apparent influence on the likelihood of residual injury. All four patients with residual injury were male. While suggestive of an influence of gender on outcome (non-significant by Fisher’s exact test) the small number of patients precluded meaningful statistical analysis. The same was true for the influence of “predisposing factors”; nine of 22 patients had some predisposing factor (see table 1) and two had a history of prior carpal tunnel release. It is uncertain if this is any different from the incidence of such factors in the general population of surgical patients. Of the four patients with residual injury, two had no predisposing factors and two were diabetic. That two of three diabetics with PBP had residual injury may suggest a poorer prognosis among diabetics. The clinical presentation differed between OHS and NCS groups. In the former, sensory impairment and pain–dysaesthesia were the prominent and consistent features. No patient had isolated or predominant motor loss and six of eight patients had sensory–pain disturbance without motor loss or of greater degree than the motor loss. In the NCS group the opposite was true. Here, motor deficit was the prominent and consistent feature. There appears to be no indication of prognosis in the particular degree and features of the initial presentation. The one exception to this was for NCS-PBP where patients with pain–dysaesthesia tended to have a prolonged recovery. Further, all three patients with residual injury had pain–dysaesthesia. Also, patients with injury to all roots tended to have incomplete or prolonged recovery. Six NCS-PBP patients had no motor recovery by 6–8 weeks. This group included all three patients with residual injury; that is 50% of patients with no motor recovery by 6–8 weeks ultimately had a Full Full Full Full Full Full Full Residual weakness Residual motor and sensory British Journal of Anaesthesia Time to. max recovery Degree of (weeks) recovery 442 Prognosis of intraoperative brachial plexus injury residual deficit. There were several other observations related to recovery; motor recovery proceeded in a caudad–cepahalad direction with the lower roots recovering sooner. Sensory recovery appears to precede motor recovery and failure to observe any sensory recovery by 3–4 weeks may also be an ominous prognostic milestone. All patients exhibited significant recovery even if recovery was not complete; temporal progression was always in the direction of recovery with no patient exhibiting deterioration. No patient in this series suffered chronic pain. Discussion The most striking finding of this study was the disparate outcomes for the OHS compared with the NCS group. Although there was no significant difference in the quantitative incidences of residual injury (one of eight patients compared with three of 14 patients) there was a qualitative difference. In the OHS group, one of eight patients suffered a mild residual tingling sensation whereas in the NCS group, three of 14 suffered residual weakness. These values are in contrast with existing opinion that nearly all intraoperative brachial plexus injuries recover, and perhaps explains the prevalence of this complication in the insurance industry data. It must be acknowledged that our methodology of case collection skewed the prognostic significance of these data to the pessimistic. A retrospective review of only those cases presenting to the hand clinic more than 1 week after operation eliminates those cases of mild and transient injury and may preferentially select those cases of motor complaint over those with sensory complaint. It has been reported that most cases of PBP after sternotomy are already asymptomatic at the time of hospital discharge.13 Parks6 reported 25 cases of PBP of whom eight suffered mild injury and recovered in an average time of 9 days. Of the remaining 17 patients, 14 recovered within 6 months and three had residual injury. Presumably our method of data collection would have missed 94% (if not all) of the cases of Tomlinson and colleagues13 and 32% of Parks’ cases.6 It is therefore impossible to judge what fraction of all cases of PBP actually went on to referral to the hand clinic. The prognostic significance of our data therefore does not relate to all patients presenting immediately after operation with PBP, but rather to some subset of “worst cases”. As a prognostic indicator these data are more representative of those patients with significant symptomatology 1 week after operation or at hospital discharge. In the OHS cases of PBP the fact that all patients achieved full functional recovery in spite of this “worst case” selection suggests an extraordinarily good prognosis for this subset of cases. While most authors concur with this optimistic outlook for OHS-PBP, a prospective study of 1000 cardiac surgery patients found 55 cases of postoperative upper extremity disturbance of whom 28 recovered within several days, 19 recovered within 3 months and eight were still symptomatic 3 months after 443 operation.14 However, as follow-up did not extend beyond 3 months it is impossible to know the final disposition of these eight patients, and it is incorrect to assume that they suffered permanent injury. In our own series, three of eight OHS-PBP patients required 3 months or more to achieve full recovery. Plexus injury after median sternotomy differs from PBP after NCS in several critical ways. First, PBP after OHS is far more common. As opposed to an incidence of 0.02–0.06% for NCS-PBP, the incidence of OHS-PBP in various prospective studies has ranged from a low of 1.9%15 to 18.3%.16 Electrophysiological evidence suggests the existence of subclinical injury in the majority of cardiac surgery patients.17 Roy, Stafford and Charlton18 summarized six prospective studies totalling 1772 patients undergoing OHS. The overall incidence of nerve injuries in these studies was 7.6% of which 80% (6.1%) were PBP. In their own prospective analysis of 162 cardiac surgery patients there were 12 (7.4%) cases of PBP. OHS-PBP also differed from NCS-PBP in the distribution of the injury. Nearly all of the former involved lower roots of the plexus whereas the latter were typically lesions of the upper and middle roots. This generalization holds true throughout the literature and our data are consistent. The mechanism of injury in OHS-PBP is different (anatomically and mechanically) from that of NCS-PBP. The positioning of sternal retractors (cephalad placement promotes injury), extent of sternal retraction (excessive retraction promotes injury) and the wide, asymmetric sternal traction necessary for harvesting of an internal mammary artery graft pedicle have been associated with PBP.14 Sternal retraction forces the clavicle into the retroclavicular space rotating the first rib superiorly and stretching the lower plexus.19 Persistent changes in somatosensory evoked potentials associated with sternal retraction predict postoperative deficits.20 On occasion, rib fracture may occur with the possibility of nerve penetration.16 21 These fractures are common when evaluated by radionuclide bone scan although they are usually not detected by x-ray.22 This mechanism may explain the more severe cases of OHS-PBP. Another difference between OHS-PBP and NCSPBP is in the clinical expression of the injury. Apart from the different anatomical distributions of the injuries, the presentation in NCS-PBP has been described as that of a relatively painless motor deficit which is greater in degree than sensory loss.8 Our data supported the relative emphasis on the motor deficit in NCS-PBP. Where sensory deficit or pain–dysaesthesia presented in the NCS group it appeared to herald prolonged or incomplete recovery and an association with injury to the roots of the lower trunk in addition to those of the upper and middle trunks. For OHS-PBP the relative emphasis is on sensory disturbance as opposed to motor loss.13 14 Our OHS-PBP patients also had primarily sensory complaints and 50% had no motor deficit. An important difference between these two categories of PBP is that of prognosis. Although there are reported cases of persistent deficit after 444 OHS, the literature indicates a high likelihood of full recovery.14 23–25 Our finding of seven patients with full recovery and one with only mild residual tingling (in spite of the “worst case” selection) is consistent with this. This compares with a less encouraging prognosis in the case of NCS-PBP. Regarding the prognosis of OHS-PBP, most patients are already asymptomatic within several days.13 14 In the study of Tomlinson and colleagues,13 94% were asymptomatic by the time of hospital discharge. Hudson, Boome and Sanpera26 reported an incidence of 0.2% of OHS patients in their centre being referred to the hand clinic for PBP. Using the incidence data from prospective studies this implies that in their institution 96–98% of patients with OHS-PBP enjoyed rapid recovery. We estimate therefore that 90–95% of patients will be wholly or substantially improved within 1 month of surgery (with full recovery forthwith). Of those patients who have not substantially recovered by the 1 week “prognostic milestone” (our presumed criteria for referral to the hand clinic) our data suggest complete or nearcomplete recovery is highly likely. Most patients recover within several months, although on occasion recovery may be protracted (up to 1 yr) and, only rarely, incomplete. In the case of NCS-PBP there are no prospective studies to allow a valid estimate of what percentage of patients have transient injury. Using the “1 week milestone” criteria, our data suggest that of those NCS-PBP patients with significant symptoms at 1 week, 79% (11 of 14) recover fully. This compares closely with Parks’ finding of 82% (14 of 17 patients) full recovery. In assessing the individual patient there are no absolute markers of prognosis. However, this study suggests several possible portents to a slower recovery and worse outcome, including male gender, diabetes, injury to all roots of the plexus, and the presence of sensory deficit and pain or dysaesthesia. Absence of sensory recovery by 3–4 weeks and motor recovery by 6–8 weeks are further negative “prognostic milestones”. Half of those patients with no motor recovery at 6–8 weeks ultimately suffered residual deficit. We stress that the data of this study are only suggestive and that the small number of patients involved precludes statistically significant conclusions. On the positive side, all patients achieved substantial, if not full, recovery. The role of physical therapy in this recovery cannot be overemphasized. In summary, brachial plexus injury occurring after cardiac and non-cardiac surgery are two separate entities. The former is characterized by a predominance of sensory complaint in the lower roots of the plexus and the latter by a predominance of motor deficit in the upper and middle roots. The former is far more frequent than the latter, with an excellent prognosis for recovery. The prognosis of brachial plexopathy after non-cardiac surgery may be worse in males, diabetics, those with injury to all roots of the plexus and when, in addition to the motor deficit, there is sensory loss and pain or dysaesthesia. At a 1 week “prognostic milestone” 79% of symptomatic patients enjoyed complete recovery, although this took as long as 5 months or more in 50% of British Journal of Anaesthesia patients. In some, recovery took up to 1 yr. At the 6–8 week “prognostic milestone” 50% of those who had not yet shown evidence of improvement in the motor deficit suffered residual neurological deficit. However, all patients recovered to a significant extent even when recovery was not complete and none suffered from late deterioration or chronic pain. The relative infrequency of this serious complication and the paucity of our literature data base imply the need for further such series and perhaps ultimately their compilation through meta-analysis. References 1. Cooper DE, Jenkins RS, Bready L, Rockwood CA. The prevention of injuries of the brachial plexus secondary to malposition of the patient during surgery. Clinical Orthopaedic and Related Research 1988; 228: 33–41. 2. Denny-Brown D, Brenner C. Paralysis of nerve induced by direct pressure and tourniquet. Archives of Neurology and Psychiatry 1944; 51: 1. 3. Denny-Brown D, Doherty MM. Effects of transent stretching of peripheral nerve. Archives of Neurology and Psychiatry 1945; 54: 116. 4. Lundburg G, Rydevik B. 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