Paraplegia After Aortic Aneurysm Repair Versus Traumatic Spinal Cord Injury: Functional Outcome, Complications, and Therapy Intensity of Inpatient Rehabilitation

Participants 

Our hospital was a rehabilitation center with 280 beds, including 80 beds in a spinal cord rehabilitation ward. Our hospital had 29 physical therapists, 18 occupational therapists, and 7 rehabilitation sports instructors. We collected retrospective data on consecutive patients with SCI-AA or traumatic SCI who were admitted to the spinal cord rehabilitation ward between 2000 and 2004.

We established the following inclusion criteria for patients in this study: (1) complete data available for age, injury level, completeness of injury, LOS in an acute care hospital and LOS in the rehabilitation center, FIM scores, ambulatory state, rehabilitation exercise time, discharge placement, complications during rehabilitation hospitalization, and preexisting medical comorbidities; and (2) admittance from the acute care hospital more than 3 weeks after injury. This was the reason that all the patients with SCI-AA admitted to our hospital after acute medical management, and more than 3 weeks later after injury.

The established exclusion criteria were as follows: (1) patients with cognitive disturbances that inhibited them from participating in the rehabilitation program; (2) patients who had severe upper-limb dysfunction that prevented them from participating in the rehabilitation program due to peripheral nerve palsy, severe hemiplegia, or severe restriction of range of motion with fracture; and (3) patients who were transferred to an acute medical hospital for the treatment of medical complications.

There were 20 patients with SCI-AA admitted during the 5-year period. One patient was excluded because he was transferred to an acute medical hospital for the treatment of a medical complication. Three patients had cerebral infarction, but they were not excluded because they had very mild hemiparesis (Brunnstrom stage V or VI of the upper extremity and hand) that did not prevent them from participating in the rehabilitation program.

There were 352 patients in the traumatic SCI group. Twenty-eight were excluded because of cognitive disturbances. Three patients were excluded due to upper-limb dysfunction (plexus injury, n=2; fracture, n=1).

The remaining 19 patients in the SCI-AA group and 321 patients in the traumatic SCI group were enrolled in this study.

Matching Procedure 

For outcomes evaluation, we used a block-design matching procedure to control for the covariant effects of injury characteristics and age at injury on the etiology effect. Three matching variables were selected: (1) level of neurologic injury, (2) ASIA impairment classification, and (3) age at time of injury.

The level of injury in all patients in the SCI-AA group was in the thoracic regions. Thus, we classified the level of injury into 2 groups: the upper thoracic region (T2-6) group and the lower thoracic region (T7-12) group. ASIA impairment classification comprised 4 grades (A through D) (table 1). Age category at time of injury comprised 2 groups: a “younger” group (<50y) and an “older” group (≥50y). The choice of age 50 years as a break point was made on the basis of previous reports.24, 25, 26 Each patient was identified by an injury type and age group classification and categorized based on etiology characteristic. Patients were selected by age (within 10y), further controlling for the covariant effects of age at injury on the etiology effect, from each etiology group to create matched dyads on the basis of the injury type and age group classification. When multiple SCI-AA and traumatic SCI patients were identified within the same injury type and age group classification, the patients were randomly matched until no more aortic aneurysmal and traumatic dyads could be created. Seventeen patients with SCI-AA were successfully matched with 17 counterparts with traumatic SCI (table 2).

Table 1. ASIA Impairment Classification

	Grade	Classification
	A	Complete: No motor or sensory function is preserved in the sacral segments S4–S5.
	B	Incomplete: Sensory but not motor function is preserved below the neurological level and extends through the sacral segments S4–S5.
	C	Incomplete: Motor function is preserved below the neurological level, and more than half of key muscles below the neurological level have a muscle grade less than 3.
	D	Incomplete: Motor function is preserved below the neurological level, and at least half of key muscles below the neurological level have a muscle grade of 3 or more.
	E	Normal: Motor and sensory function are normal.

NOTE. Reprinted with permission. ©2000 American Spinal Injury Association.

Table 2. Matching: Paraplegia After AA Repair Versus Traumatic SCI

	Patients	SCI-AA	Traumatic SCI
		(n=17)	(n=17)
		(Age [y]/LOI/ASIA grade)	(Age [y]/LOI/ASIA grade)
	1	46/T12/A	45/T9/A
	2	52/T8/A	53/T11/A
	3	59/T7/A	57/T11/A
	4	64/T9/A	58/T9/A
	5	64/T7/A	63/T10/A
	6	65/T5/A	67/T5/A
	7	68/T11/A	65/T12/A
	8	70/T7/A	70/T12/A
	9	32/T10/B	35/T12/B
	10	46/T12/B	46/T12/B
	11	56/T9/C	51/T12/C
	12	61/T10/C	53/T12/C
	13	68/T7/C	65/T12/C
	14	56/T9/D	55/T9/D
	15	60/T12/D	56/T12/D
	16	63/T9/D	62/T9/D
	17	67/T12/D	71/T12/D

Abbreviation: LOI, level of injury.

Therapy Intensity 

The standard rehabilitation program for patients with paraplegia was composed of 40 minutes of physical therapy (PT), 40 minutes of occupational therapy (OT), and 40 minutes of rehabilitation sports therapy per day, 5 days a week. We counted every 40 minutes of exercise in the gymnasium as 1 therapy session. Bedside exercises were not included, because aggressive exercises could not be done in those circumstances. We counted the number of patients receiving each therapy, the total number of therapy sessions during the rehabilitation hospitalization, and the therapy intensity.

Outcome Measures 

Outcomes variables were as follows: LOS in the acute and rehabilitation hospitals; FIM score27; FIM change (discharge FIM minus admission FIM); FIM efficiency (FIM change divided by LOS); ambulatory state at discharge; discharge to the community; total therapy sessions and therapy intensity; complications during rehabilitation hospitalization; and preexisting medical comorbidities.

Ambulatory state was classified into 2 groups: ambulatory and nonambulatory. The ambulatory subjects were defined as those who could walk within homes with or without orthoses or devices. Complications during rehabilitation hospitalization and preexisting medical comorbidities were collected from medical records.

Data Analysis 

We conducted data analyses to compare the relationship between patients with SCI-AA and their counterparts with traumatic SCI. Independent 2-tailed t tests were performed between the 2 groups for parametric data. Chi-square analyses were also performed to determine group differences for nonparametric data. The level of statistical significance was set at P less than .05.

Participants 

The etiology of the SCI-AA group (n=17) was dissecting aneurysm in 13 (76.4%) patients, descending thoracic AA in 1 (5.9%) patient, thoracoabdominal AA in 2 (11.8%) patients, and infrarenal abdominal AA in 1 (5.9%) patient. DeBakey classification of dissecting aneurysms was the following: type I, 4 patients; type II, 1 patient; type IIIa, no patients; and type IIIb, 8 patients. The identifiable etiology for the dissection was Marfan syndrome (1 patient). Thirteen (76.4%) patients underwent surgical therapy and 4 (23.6%) patients were treated medically. Surgical therapy was elective in 6 patients for rapid expansion, and urgent or emergency in 7 patients for symptoms such as chest pain, back pain, or abdominal pain. Of these 13 patients who underwent surgical therapy, 3 patients had preoperative paraplegia and 10 patients became paraplegic after surgery. In all 4 patients who were treated medically, paraplegia was observed on admission into the acute hospital. The etiology of the traumatic SCI group (n=17) was fall in 13 (76.4%) patients and motor vehicle collision in 4 (23.6%) patients. The mean age of subjects in the SCI-AA group and the traumatic SCI group was similar (58.6y vs 57.2y, respectively). The level of injury of each of the 2 groups was from T5 to T12. As for the ASIA classification of the 2 groups, 8 patients were grade A, 2 patients were grade B, 3 patients were grade C, and 4 patients were grade D.

Length of Stay 

LOS in an acute hospital was similar between the SCI-AA and traumatic SCI groups (85.1d vs 68.1d, respectively). Also, for LOS in the rehabilitation hospital, no significant differences were noted between the 2 groups (135.1d vs 115.6d, respectively) (table 3).

Table 3. LOS, Rate of Return to the Community, and Rate of Return to Ambulatory State at Discharge: Paraplegia After AA Repair Versus Traumatic SCI

	Variables	SCI-AA	Traumatic SCI	P
		(n=17)	(n=17)
	LOS
	Mean acute hospital ± SD (d)	85.1±45.0	68.1±32.9	.22
	Mean rehabilitation hospital ± SD (d)	135.1±42.0	115.6±35.8	.16
	Rate of return
	To the community (%)	82.4	100%	.07
	To ambulatory state at discharge (%)	17.6	35.3	.243

Abbreviation: SD, standard deviation.

FIM Comparison 

There were no significant differences between the 2 groups in the admission FIM total, motor, and cognitive scores. Significant differences were noted between the SCI-AA and SCI groups, respectively, in the discharge FIM total scores (95.6 vs 107.2, P<.05), FIM motor scores (62.7 vs 72.8, P<.05), FIM total change (23.5 vs 33.2, P<.05), FIM motor change (23.4 vs 32.8, P<.05), and FIM efficiency (.182 vs .308, P<.01). There were no significant differences between the 2 groups in the discharge FIM cognitive score and FIM cognitive change (table 4).

Table 4. FIM Comparison: Paraplegia After AA Repair Versus Traumatic SCI

	FIM Measures	SCI-AA	Traumatic SCI	P
		(n=17)	(n=17)
	Admission FIM	72.1±16.1	74.1±14.0	.72
	Discharge FIM	95.6±16.2	107.2±11.1	.02
	FIM change	23.5±10.6	33.2±13.5	.03
	FIM efficiency	0.182±0.095	0.308±0.128	<.01
	Admission FIM motor	39.4±15.7	40.1±13.6	.89
	Discharge FIM motor	62.8±15.0	72.8±10.4	.03
	FIM motor change	23.4±10.6	32.8±13.3	.03
	Admission FIM cognitive	32.8±3.77	34.0±2.00	.25
	Discharge FIM cognitive	32.9±3.55	34.4±1.28	.11
	FIM cognitive change	0.12±0.47	0.41±1.70	.51

NOTE. Values are mean ± SD.

Ambulatory State and Discharge to the Community 

There were no significant differences between the 2 groups in the rate of return to an ambulatory state (17.6% for SCI-AA vs 35.3% for SCI) and return to community (82.4% for SCI-AA vs 100% for SCI) at discharge (see table 3).

Complications and Preexisting Medical Comorbidities 

There were no significant differences between the 2 groups in the occurrences of complications related to SCI, such as pressure ulcers, urinary tract infections, bladder stones, heterotopic ossification, ileus, and pain during rehabilitation hospitalization. Complications related to AA or atherosclerotic disease, such as cerebral infarction in 1 patient and cardiac disease in 2 patients and occlusion of peripheral artery in 1 patient during rehabilitation hospitalization, were noted in patients in the SCI-AA group. One patient with SCI-AA had recurrent pneumonia and required tracheostomy during the rehabilitation hospitalization (table 5).

Table 5. Complications During Rehabilitation Hospitalization and Comorbid Medical Complication: Paraplegia After AA Repair Versus Traumatic SCI

	Complications and Comorbidities	SCI-AA	Traumatic SCI	P
		(n=17)	(n=17)
	Complications during rehabilitation hospitalization
	Pressure ulcers	8	4	.151
	Urinary tract infections	6	5	.714
	Bladder stones	2	1	.545
	Heterotopic ossification	2	0	.141
	Pain	2	1	.545
	Ileus	1	0	.31
	Cardiac disease	2	0	.141
	Angina pectoris	2	0	.141
	Cerebral infarction	1	0	.31
	Occlusion of peripheral artery	1	0	.31
	Pneumonia	1	0	.31
	Tracheostomy insertion	1	0	.31
	Preexisting medical comorbidities
	Hypertension	16	4	<.01
	Cardiac disease	7	1	.01
	Angina pectoris	3	1	.29
	Myocardial infarction	1	0	.31
	Chronic heart failure	1	0	.31
	Sick sinus syndrome	1	0	.31
	Atrial fibrillation	1	0	.31
	Renal insufficiency	1	0	.31
	Cerebral infarction	2	0	.141
	Hyperlipemia	3	0	.07
	Patency of the false lumen	1	0	.31
	Hyperuricemia	2	0	.141
	Diabetes mellitus	0	2	.141
	Insulin-dependent diabetes mellitus	0	1	.31
	Non-insulin−dependent diabetes mellitus	0	1	.31

NOTE. Values are numbers of patients.

Significant differences were noted in the preexisting medical comorbidities between the 2 groups, such as the prevalence of hypertension and cardiac complications (angina pectoris, prior myocardial infarction, chronic heart failure, arrhythmias). There were no significant differences between these groups in the preexisting medical comorbidities, such as hyperlipemia, hyperuricemia, or diabetes mellitus. In the SCI-AA group, 1 patient had a patent false lumen that was thought to contribute to a risk of rupture or dissection.28 Another patient in the SCI-AA group had renal insufficiency, which was defined as a serum creatinine level of 2.0mg/dL or more. A serum creatinine of this patient was simply elevated, and he was not on hemodialysis. Two patients in the SCI-AA group had a preexisting cerebral infarction (see table 5).

Therapy Comparison 

There were no significant differences between the SCI-AA and SCI groups in the number of patients receiving PT (17 vs 17, respectively) and OT (14 vs 10, respectively). Significant differences were noted between these groups in the number of patients receiving rehabilitation sports therapy (0 vs 7, respectively; P<.01). The amount and the intensity of PT and OT were similar between the SCI-AA and SCI groups (PT amount, 75.5 vs 69.8 sessions, respectively; PT intensity, .58 vs .65, respectively; OT amount, 41.8 vs 32.3 sessions, respectively; OT intensity, .31 vs .26, respectively). Significant differences were noted between the SCI-AA and SCI groups in the amount and intensity of rehabilitation sports therapy (amount, 0.0 vs 12.4 sessions, respectively, P<.05; intensity, 0.00 vs 0.11, respectively, P<.05). The amount of total therapy sessions during the rehabilitation hospitalization was similar between the SCI-AA and SCI groups (117.3 vs 114.6 sessions, respectively), and no significant differences were noted in therapy intensity (0.889 vs 1.024, respectively) (table 6).

Table 6. Therapy Comparison: Paraplegia After AA Repair Versus Traumatic SCI

	Variables	SCI-AA	Traumatic SCI	P
		(n=17)	(n=17)
	Received no. of patients
	PT	17	17	—
	OT	14	10	.132
	RST	0	7	<.01
	Total sessions of each therapy
	PT	75.5±27.3	69.8±14.9	.46
	OT	41.8±27.9	32.3±32.3	.367
	RST	0.0±0.0	12.4±22.0	<.05
	Total	117.3±49.7	114.6±51.1	.876
	Therapy intensity⁎
	PT	0.583±0.183	0.654±0.237	.336
	OT	0.306±0.212	0.263±0.256	.60
	RST	0.000±0.000	0.106±0.181	<.05
	Total	0.889±0.340	1.024±0.345	.261

NOTE. Values are n or mean ± SD. Abbreviation: RST, rehabilitation sports therapy.

⁎ Total sessions of therapy including PT, OT, and RST divided by LOS in days.

Study Limitations 

This study had several limitations. The number of subjects was relatively small, which increased the chance of error. Furthermore, because the results reflect the practice and referral pattern of only 1 rehabilitation center, the generalization of the findings is limited. Patients with SCI-AA not admitted to the spinal cord rehabilitation ward included the following: those who died at the acute hospital, those with very mild ischemia who recovered quickly at the acute hospital and did not need inpatient rehabilitation therapy, and those who had a poor prognosis for rehabilitation and were transferred to another hospital, nursing home, or palliative care unit.

The matching process in this study was broad in age, level of injury, and ASIA impairment classification. Other factors or preexisting medical comorbidities will affect both outcome and potential recovery after AA repair. But preexisting medical comorbidities were different between the SCI-AA and traumatic SCI groups.

The implication of the results of the present study is that prospective studies of patients with SCI-AA are needed. Future studies should include a larger sample size, should be done by multicenter research, including acute hospitals, documentation of complications and preexisting medical comorbidities, rehabilitation therapy from the acute hospital, and long-term follow-up outcome.