Dysvascular Amputees:What Can We Expect?
Sheryl P. Anderson, CP
ABSTRACT
The medical records of 385 amputees
were studied to determine if the trends of
high occurrence of death and second
amputation for patients with vascular
disease still exist and if so, to what degree. All the subjects experienced their
first amputation between Jan. 1, 1982,
and Dec. 3], 1987. Their patient charts
were followed for a five- to 1O-year period, as applicable, from the date of first
amputation until the last entry prior to
Dec. 31, 1992.
Multiple amputations occurred in 59
percent of the patients. Thirty-five percent of the subjects underwent a revision
to the original amputation within an average of 6.5 months. Contralateral amputation was performed on 30.9 percent
of the subjects. Contralateral amputation occurred an average of 24.9 months
following the first amputation. Eighteen
percent of all patients studied died within the time frame of this study. The average time between contralateral amputation and death was 18 months.
Introduction
Eighty percent of all lower-limb amputations result from vascular disease (1).
Historically, this population has proven
to be at high risk for revision to a higher level and/or contralateral amputation due to complicating health factors
(2). This study is an attempt to identify
the magnitude of this and other problems in today's patients with vascular
disease.
As early as the 1860s, a trend had
been noted concerning the postamputation lives of patients with vascular
disease. This trend was clearly demonstrated in a preliminary report of a
study by Goldner (3) involving 71 diabetic patients with diabetic gangrene or
amputation of one lower limb. Of the
71 patients, 47 showed involvement of
the contralateral limb while five experienced complications with their existing
residual limb. Fifty percent of these patients had developed complications of
the second limb within two years of the
first amputation. Only three of the patients in the study preserved an intact
contralateral lower limb for more than
five years.
More recently, Ebskov and Josephsen (2), who conducted a retrospective
study of 2,029 amputations, showed the
same trend but to a lesser degree. Four
years postoperatively 36.6 percent of
the amputees' residual limbs were in
good condition while 9.5 percent required revision to a higher level. Thirty-one percent had encountered problems
with the contralateral limb, resulting in
amputation, and 25.5 percent of the patients had died within the four-year period.
Ebskov and Josephsen noted another interesting trend during this study:
Mortality rate decreased as the postoperative time period increased. Their
study showed that the greatest risk of
death occurs within three months following amputation. During this three-month period, the death rate is significantly higher than that of the "normal"
population. At six months postoperatively, the death rates of amputee and
"normal" populations are approximately equal. At any date later than six
months postoperatively, the survival
rate of the amputee population is significantly higher than that of the "normal" population. A similar observation
was made by Tripses and Pollak (4)
when reviewing 61 charts of vascular patients who had undergone amputation.
Their study showed that as the postoperative time period increased, mortality
rate and the incidence of reamputation
at a higher level decreased.
These seemingly positive findings are
more an exception than the rule. A
steady mortality rate over a seven-year
period was a prominent finding of a
study conducted by Whitehouse, Jurgensen and Block (5). Their study, involving 67 patients, revealed that 60
survived one year, 44 two years, 30
three years, 14 five years, 6 seven years,
and only 3 patients were alive nine
years postoperatively. Bodily and
Burgess (6) conducted a study in which
53 patient charts were reviewed. The
data obtained from these charts were
then analyzed using actuarial statistics
to determine the rate of contralateral
limb survival following an amputation.
Their analysis showed that within two
years postoperatively, 50 percent of the
patients required an amputation of the
contralateral limb. Within three years
following amputation, 50 percent of the
patients had died.
Many other interesting points were
noted during a review of studies concerning postoperative complications of
dysvascular patients. Research by Otteman and Stahlgren (7) revealed that an
average of 30 months separated the
first and second amputations in patients involved in their study. Research
conducted by Harris, Page, Englund
and May (8) found that the risk of losing a contralateral limb to amputation
increases approximately 10 percent per
year following initial amputation. Their
study also indicated no significant difference in the survival rates of diabetic
vs. non-diabetic patients. This finding is
supported by Tripses and Pollak (4),
who concluded that there is no difference in frequency between postoperative complications of diabetic vs. nondiabetic patients. Ebskov and Josephsen (2) also found no significant differences between diabetic and non-diabetic patients when studying the incidences of reamputation and death after
gangrene. Siitonen et al. (9) concluded
that "...amputations of diabetics were
markedly overrepresented" when comparing the outcome of diabetic and
non-diabetic patients after lower-limb
amputation due to vascular disease.
Britton and Barrie (10) conducted a
retrospective study over a 10-year period, which included 119 patients. This
study showed that 30 patients (25 percent) required amputation of the contralateral limb within three years postoperatively. Eighteen of these 30 patients underwent their second amputation within 12 months of the first
surgery. Thirty-nine patients (33 percent) died within three years following
amputation.
All of the research cited above has
shown fairly consistent results. The occurrence of second amputations of the
contralateral limb was shown to exist in
25 percent to 55 percent of the patients
within three years postoperatively. Furthermore, the studies discussed above
indicated that the mortality rate of the
dysvascular population ranges from 33
percent to 55 percent three years after
initial amputation surgery.
Two of the studies, those by Goldner
(3) and later by Ebskov and Josephsen
(2), were published in 1960 and 1980,
respectively. It should be noted an appreciable decrease, although not statistically significant, occurred in the percentage of amputees requiring amputation of the contralateral limb during
those 20 years. In the literature search
conducted for this study, articles reviewing patient charts more recent
than 1984 were not found. The purpose
of this study was to determine if the
trends of high occurrence of death and
second amputation, both of the contra- and ipsilateral limbs, still exist and if so,
to what degree.
This study, which was retrospective
in design, was undertaken to determine
the rate of second amputations in people with vascular disease, the cause of
amputations and the postamputation
life span of this population.
Methodology
Subjects
Subjects included in this study met the
following criteria:
- must have been diagnosed with
vascular disease (either peripheral atherosclerotic disease, diabetes mellitus
or both)
- must not have been diagnosed with
juvenile diabetes
- must have undergone first amputation between 1982 and 1987
- must have complete records available
The medical charts of patients who
met the above criteria were reviewed
through 1992, a period of five to 10
years after the first amputation. Files
from two hospitals in the Dallas area
were reviewed. Parkland Memorial
Hospital (PMH) is a widely recognized
trauma center funded by Dallas county.
Presbyterian Hospital of Dallas (PH) is
a private hospital that cares predominantly for patients with private insurance. In an attempt to eliminate sampling error, these two hospitals were
chosen since their patient populations'
economic and social backgrounds varied widely. The occurrence of such an
error would necessitate limiting the
generalization of the findings to a particular socioeconomic population.
Data Analysis
Statistical analysis was performed using
the SAS software package. The t-test
was used to compare two groups. Comparison of three or more groups was
conducted using analysis of variance
(ANOVA). Survival curves were created using the Kaplan-Meier method and
were then compared using the LogRank test. Statistical data pertaining to
survival curves are presented using
plots of survival estimates. Descriptive
statistics also were prepared using the
SAS program. Significance was established at p<0.05.
Results
The medical records of 385 amputees
were studied with the review covering a
five- to 10-year period, as applicable,
for each amputee. Of these amputees,
322 were PMH patients; 63 were patients of PH. All of the patients included in the study experienced their first
amputation between Jan. 1, 1982, and
Dec. 31, 1987. Their charts were followed from the date of first amputation
to their last entry prior to Dec. 31, 1992.
The average age of a patient undergoing a first amputation was 63 (+/-11.6)
years. The 60- to 69-year age group had
the most amputees (see Figure 1
).
Diagnosis
Two hundred twelve of the subjects
were diagnosed with diabetes mellitus
(DM); 74 were diagnosed with peripheral atherosclerotic disease (PVD); and
99 had a diagnosis of both diabetes
mellitus and peripheral atherosclerotic
disease (DM/PVD). The age at diagnosis was available for 191 of the 385 patients. The average age at diagnosis of
those patients with DM was 47 (+/-12.6),
PVD was 60 (+/-7), and DM/PVD was 46
(+/-13) years. Statistical analysis indicated that subjects with PVD were significantly older at diagnosis than those
with DM or DM/PVD.
It also was found that those patients
diagnosed with only PVD received
their first amputation within a significantly shorter time period (4.4 years)
after diagnosis than patients who were
diagnosed with DM (12 years) or
DM/PVD (15 years). Patients diagnosed with DM underwent second amputation at a significantly slower rate
than those diagnosed with PVD or
DM/PVD. Four years after the first amputation, 58 percent of the DM group
had undergone a second amputation
whereas 83 percent of both the PD and
DM/PVD groups had undergone second amputations (see Figure 2
). The
DM group received the second amputation less often than the other two
groups during the first four years. Beyond four years, the rate of second amputation for the DM group approached
that of the other groups.
Twenty-four of the 141 patients
whose DM diagnosis age was known
died within the time frame of this study.
The average time between diagnosis
and death was 18.5 (+/-10) years. One of
the six patients who had a documented
PVD date of diagnosis expired 17.5
years after the date of diagnosis. Nine
of the 44 patients who had a known
date of diagnosis of DM/PVD died. The
average time between the two events
was 10.7 (+/-6.7) years.
Cause
Cause of amputation was recorded for
317 patients. Causes included gangrene,
ulcer, infection, osteomyelitis, poor circulation, pain, poor healing and trauma. To perform statistical analysis, two
groups were formed: "gangrene" and
"other." One hundred seventy-one patients underwent their first amputations secondary to gangrene while 146
resulted from one of the other causes
listed. It was found that the cause of the
first amputation correlates with the incidences of death and second amputation. Those patients who underwent a
first amputation due to gangrene expired at a significantly faster rate than
patients who underwent their first amputation secondary to other reasons
(see Figure 3
). At four years, 28 percent
of the gangrene group had expired
while only 17 percent of the "other"
group had expired. This difference between the gangrene group and the
"other" group was more striking less
than four years after amputation and
became less noticeable after four years.
Also, patients who underwent original amputation secondary to gangrene
required a second amputation, either
ipsilateral or contralateral, within a significantly shorter time period than
those who underwent first amputation
due to other reasons (see Figure 4
).
Multiple Amputations
Of the 385 amputees included in the
study, 212 (55 percent) required more
than one amputation (either contralateral or revision to a higher level). The
remaining 173 subjects required only
one amputation. Of those patients requiring multiple amputations, 137 (65
percent) underwent a revision to the
original amputation.
Figure 5
provides a comparison of
the level of first amputation and frequency of revision of that level of amputation. Patients who initially underwent a partial-foot amputation had a
revision to a higher level 45 percent of
the time. Transtibial (below-knee) amputees underwent revision 32 percent
of the time. Six percent of those patients who initially received a transfemoral (above-knee) amputation required a revision.
The average time between the first
amputation and the first revision was
6.5 (+/-13.4) months. Twenty-eight (20
percent) patients requiring a revision
underwent a second revision to the
original amputation within an average
of five (+/-12.3) months.
Contralateral amputation was experienced by 119 subjects, or 31 percent,
of all patients included in this study and
occurred an average of two (+/-2) years
following the first amputation. Nineteen (16 percent) of the amputees requiring a contralateral amputation
showed a record of expiration. The average time span between the contralateral amputation and expiration was 1.5
(+/-1.2) years.
Mortality
Eighteen percent of the subjects died
during the time frame of this study. Of
the 212 patients who required a second
amputation, 17 percent expired. Death
was documented in 18.5 percent of the
cases requiring a single amputation.
Figure 6
shows patient mortality as well
as the time from first amputation to
death. The patients are divided into
those requiring two or more amputations and those who underwent only
one amputation. It is interesting to note
that within the first two years following
amputation, patients who received only
one amputation died more quickly.
Thereafter, patients who underwent
multiple amputations expired at a
faster rate.
Patients who underwent a single amputation and expired during the time
frame of this study lived an average of
65 (+/- 8.9) years and died an average of
1.5 (+/-2.1) years after the amputation.
Those who required more than one amputation had an average life span of 69
(+/- 10) years and lived an average of 2.4
(+/-2.3) years past the date of their last
amputation. Figure 7
plots the survival
rate of all patients from time of first
amputation to last record.
Survival analysis resulted in some interesting findings. There was no correlation between diagnosis and time from
first amputation to death. Patients who
had only one amputation did not live as
long as those who underwent a revision
to a higher level. Subjects whose first
amputation was at the partial-foot level
lived longer than those whose first amputation was at a higher level, but they
had a second amputation at the same
rate.
Follow-up
Patients who underwent a single amputation and showed no record of expiration had their last entry into the medical records an average of 2.4 (+/-2.9)
years after their amputation. For subjects who received multiple amputations but did not expire during the time
frame of this study, the average time
between the first amputation and the
last entry into their medical charts was
3.5 (+/-2.8) years.
Discussion
Various authors have reported the average age at first amputation to be from
70 to 79 years (10-12). However, the average age of a patient requiring a first
amputation in this study was 63 years.
This is consistent with the findings of
studies by Bodily and Burgess (6) and
Otteman and Stahlgren (7) who reported 63.4 years and 67.4 years, respectively, to be the average age at initial amputation.
Harris et al. (8) reported no significant difference in the survival rates of
the diabetic and non-diabetic patients
included in their study. The findings of
this study agree with those of Harris et
al. Patients included in this study who
were diagnosed with DM and who expired did so an average of 0.5 years before those diagnosed with PVD.
Siitonen et al. (9) concluded that diabetics were younger at the time of lower-extremity amputation and at the
time of death than non-diabetics. Similarly, the results of this study showed
that patients with DM or DM/PVD
were significantly younger at the time
of initial amputation than those with
PVD.
Thirty-six percent of the patients
included in this study underwent a revision to their initial amputation. This ca
be compared with studies by Britton
and Barrie (10) and Ebskov an
Josephsen (2) that showed 65 percent
and 23 percent, respectively, of their
subjects requiring revision surgery. Ebskov and Josephsen (2) reported that
18.8 percent of their subjects underwent a revision within six months with
the rate only slightly increasing to 23.1
percent up to four years following the
original amputation. These values are
significantly less than the 32.1 percent
at six months and 57.1 percent at four
years found by this study. The high incidence of revision found during this
study could be attributed partly to the
patient population of PMH, which
comprises the majority of this study. Patients are often referred to PMH from
other hospitals when their medical situation proves to be highly complicated.
Amputation of the contralateral limb
was experienced by 31 percent of the
subjects included in this study. Twenty-four percent of the patients underwent
contralateral amputation within two
years of the first amputation. This finding is similar to those reported by Ecker and Jacobs (13) and Ebskov and
Josephsen (2) who showed 25 percent
and 27 percent, respectively. These values diverge significantly by the four-year mark. This study found 27 percent
of the patients required contralateral
amputation while Ecker and Jacobs
(13) reported 42 percent and Ebskov
and Josephsen (2) showed 44 percent
(see Figure 8
).
Sixty-nine (18 percent) of the 385
subjects included in this study expired.
Ebskov and Josephsen (2) showed a 23
percent mortality rate after four years
while Whitehouse et al. (5) reported an
overall 70 percent expiration after nine
years. These values are significantly
higher than those found in this study
(see Figure 9
).
Conclusion
The findings of this study have shown
varying degrees of consistency with
comparative research as discussed
above. Sixty-three years was found to
be the average age at initial amputation. It was discovered that patients
with PVD were significantly older than
those diagnosed with DM or DM/PVD
at the time of initial amputation. Thirty-six percent of the patients underwent a
revision to their initial amputation,
with the average time between the first
and second amputations being 6.5
months. Amputation of the contralateral extremity was experienced by 31 percent of the subjects, and the average
time between first amputation and contralateral amputation was two years.
Sixty-nine (18 percent) of the 385 subjects included in this study expired.
It was found that patients diagnosed
with PVD were older at diagnosis, underwent first amputation more quickly
after being diagnosed, and required a
second amputation faster than those
with DM or DM/PVD. This could be
due to the fact that these patients do
not usually receive as much preoperative care as patients with DM. Therefore, their medical condition is more serious upon initial presentation.
Patients who required a first amputation due to gangrene underwent a second amputation, ipsilateral or contralateral, and died more quickly than
those whose first amputation was the
result of a different cause. This finding
indicates the need for increased postoperative care for patients who require
amputations secondary to gangrene.
Another finding of this study was
that patients who experience multiple
amputations will have a relatively short
life expectancy. Following a first amputation, a revision to a higher level occurs an average of 6.5 months later.
Contralateral amputation occurs an average of two years after initial amputation, and death an average of 1.5 years
following the contralateral amputation.
It is apparent that one of the most valuable services we can provide our dysvascular patients is orthotic intervention as a preventive measure.
This study, being retrospective by design, has some inherent weaknesses.
Control is difficult due to differences in
surgeons, preoperative and postoperative care, and availability of diabetes
and foot clinics. While the results of this
study have indicated that advances in
medical treatment of dysvascular patients may have improved certain
trends, the need for additional research
is clear. The variety of physicians and
allied health professionals who care for
these patients as well as the patients
themselves can directly benefit from
additional, well-focused research to enhance the quality of pre- and post-amputation care and maintenance.
A prospective study in which the
variables are limited and controlled
would lead to more accurate information and improve internal and external
validity. A controlled prospective study
also would improve the ability to generalize the findings. Research that includes all patients with DM and/or
PVD would serve the medical profession well. This would provide the O&P
practitioner with information about
what to expect of dysvascular patients
in general rather than just dysvascular
amputees.
Acknowledgments
The support from the faculty of the prosthetics-orthotics baccalaureate program at
The University of Texas Southwestern
Medical Center at Dallas Allied Health Sciences School is appreciated. The author
thanks Robert Kuenzi, CP, for his guidance
and editorial contributions.
SHERYL P ANDERSON, CPO is assistant
instructor at the University of Texas Southwestern Medical Center at Dallas, Allied
Health Sciences School, 601] Harry Hines
Blvd., Suite V-S 400, Dallas, TX 75235.
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