Fifteen Years of Experience in Treating 2177 Episodes

of Foot and Leg Lesions with the Circulator Boot

 

Results of Treatments with the Circulator Boot

 

Richard S. Dillon, M.D.

 

Bryn Mawr Hospital

Department of Medicine

Section  of Endocrinology

 

Jefferson Medical School

Ó 1997 Westminister Publications, Inc. 708 Glen Cove Avenue, Glen Head, N.Y. 11545, U.S.A.

 

 

 

                  

                  

 

Abstract

 

Objective: To determine the clinical effectiveness of the end-diastolic pneumatic compression boot and of local antibiotics in treating limb lesions associated with diabetes and peripheral arterial, venous and neuropathic disease.

Research  Design and Methods: Office and hospital data were kept over 15 years on 2177 episodes of leg problems classified by the Wagner method for 1514 legs of 1035 patients largely referred because of failure of standard therapies. The fate of the untreated legs served  as a controls when possible.

Results:  Healing  or improvement of treated legs was seen above that in the literature in all Wagner categories and was significant  (P<0.001) compared to the “control” leg which deteriorated in 38.7% of patients. Significant risk factors against a successful outcome included smoking, inability to walk, increased home distance from the boot center, loss to treatment, hemodialysis, a Wagner 4-5 classification, inoperable iliac occlusions,  vascular procedures before or after referral for boot therapy and an aggressive vascular surgeon. Neuropathy allowed successful treatment of lesions nondiabetic patients could not tolerate. Relapse was significantly more frequent in ASO patients with diabetes than without diabetes and in patients with neuropathy than those with ASO.  Diabetes did not affect the relapse rate in stasis disease. The overall percentage of legs having major amputations was low: 2.46% for diabetic legs at the initial treatment episode, 1.6% at the time of a relapse and 4.14% after seeking treatment elsewhere. For nondiabetic patients, the respective risks were similar:  2.0%, 1.18% and 2.88%.

           

 

 

Introduction

                Limb loss in diabetic patients has continued to be a problem in spite of the development of new antibiotics, new methods of limb vascularization and new emphasis on preventive measures (1,2,3,4,5). Approximately one third of limbs compromised enough to be referred to a tertiary care program or compromised enough to earn a Wagner 3-4 classification are amputated (6,7,8).  The contralateral limb is also at great risk with the risk of amputation exceeding 50% within the first four years after the loss of the first leg (9). In one study, contralateral amputation was required in one-third of patients after a mean of eight months(10). The Circulator Boot System is a patented system developed to treat these difficult legs.  Directions for the use of the boot equipment are detailed in the company manual and in the section on “Method of Treatment” elsewhere in this supplement. The “boot” is an end-diastolic pneumatic compression boot system designed to improve the arterial circulation in the leg(11) and has been shown to improve significantly most tests of peripheral arterial perfusion(12). Resistant venous lesions also respond to therapy(13).  It is difficult to design and hold together a large controlled prospective study,  especially for the feet of elderly patients with arteriosclerosis and neuropathy associated with diabetes,  slow healing, frequent relapses, decreased allowed time for hospital care, and transportation problems for long term outpatient care.  Indeed, there are no such studies to justify the revascularization  procedures, for example,  practiced in our hospitals today.  In an attempt to make each patient his/her own control, I have published  two reports on consecutive patients who had been offered the option of leg amputation, standard therapies having failed, or boot therapy.  In the first study, 33 of 34 legs were spared major amputations (14); and in the second study, of 35 patients with 42 episodes of osteomyelitis, all were spared major amputation(15). The technique and advantages of the combined treatments: Circulator Boot treatments, local antibiotic injections and antibiotic-containing multielectrolyte solutions have been described in detail(16). The importance of the multielectrolyte solution in wound healing has been reported separately(17). The multielectrolyte solution used in our patients was Sea Soaks-TM  of Circulator Boot Corp., an isotonic sterile filtrate of sea water. This report summarizes 15 years of experience in treating 2177 episodes in 1035 patients, who were largely referred because of failure of previous therapy.

 

 

Methods

Treatment Setting: Patients were treated in the Bryn Mawr Hospital ( a prosperous community teaching hospital  with a strong vascular surgery service), the private outpatient  office of the author or a local nursing home boot facility. Because of  pressures from our utilization committee and insurance companies, inpatient care was limited to those who were in the hospital at the time of  their initial referral, to those with general medical problems (heart, kidney, etc.) that warranted hospitalization independent of their leg problems, and to those with sepsis.  Inpatients with leg problems so advanced  to make outpatient follow-up difficult were transferred to the nursing home boot facility where their progress was reviewed weekly by the doctor who provided typed orders at  weekly intervals for the lay boot technicians. Otherwise, all lesions from a Wagner 1 to a Wagner 5 were treated in an outpatient setting.

Origin of Patients: The origin of the patients was tabulated to be related to outcome. A particular source was listed for the patient if that source was listed by the patient as the referring physician or, in the absence of such a note, if the physician was the person making the initial contact with our office. Patients were listed as coming from the practice of the author if they were either followed there for years (relatively few) or if they had been followed for several months and treated conservatively  before boot therapy was added to their program.

Age and Sex of Legs:  Overall, the number of legs treated (average +/- standard deviation for age at presentation) were 356 female diabetic legs  (68.16+/-14.36 years), 295 female nondiabetic legs (72.71+/-12.86 years), 551 male diabetic legs (66.43+/-10.86 years) and 293 male nondiabetic legs (68.79+/-13.00 years).

Accumulated Historical and Photographic Data: At the time of their initial visit, photographs were taken of any foot lesions present and the foot was classified according to the Wagner classification: “0” if skin intact and only bony deformities; “1” if a localized superficial ulceration and/or cellulitis; “2” if a deep ulcer to tendon, bone, ligament or joint; “3” if a deep abscess or osteomyelitis; “4” if gangrene of toe(s) or forefoot; and “5” if gangrene of the whole foot (18). If a foot appeared blue and cold on presentation but warmed with a single treatment, it was considered a “0”. Suggested standards of a Vascular Surgery Society for reports dealing with lower extremity ischemia were also noted (19).  Their categories 0 to 4 varied from no symptoms, mild claudication, moderate claudication, moderate claudication to rest pain. Their category 5 (minor tissue loss) is similar to Wagner 2 and 4 while their category  6 (major tissue loss extending above the TM level) is similar to Wagner 5. Since 1990, the questionnaire reported by Regensteiner et al was used in following walking capacity (20). A record was begun for each leg. Name of referring source, patient name and home address, leg involved, patient date of birth, date of presentation for each leg for boot treatment, date of onset of the current chief complaint, estimate of  the maximum walking distance in feet, Wagner classification, smoking history, the presence and type of diabetes, history of previous TIA or stroke, New York Heart classification, number and kind of previous vascular procedures and previous amputations were noted. Subsequently, the effect of our initial treatments were noted along with later relapses (up to 3 relapses allowed on the computer columns), the results of their treatments and the results of treatments obtained elsewhere if the patient left our care. A few patients had more than three relapses, which, unless they resulted in a leg amputation, are not included. An attempt was made to reach all patients or their families over the three months prior to the tabulation of  the data for this manuscript. Their date of death and any  major amputation is included in our data whether associated with our treatment or that performed elsewhere.

              Distribution of Treatments in Three Major Disease Categories: Arteriosclerosis Obliterans (ASO), Neuropathy and Stasis According to Physical and Vascular Laboratory Findings:  The status of peripheral pulses was noted and appropriate noninvasive vascular testing was accomplished unless provided from recent outside records. Our vascular tests might include Doppler mapping if an arteriogram was not available and arterial reconstruction was an option. Routine pulse volume measurements, segmental blood pressures, the ankle/arm blood pressure ratio (ABI), photoelectricplethsmyography (PPG) tracings of the toes or ulcer edges and, in the last few years, transcutaneous PO2 and PCO2  levels were recorded as indicated. The presence or absence of deep tendon reflexes and the sensations of light touch, position and vibration were noted. The capacity to sense the standard 5.10 and 6.05 fibers and two-point discrimination (the ability to correctly identify the pressure of one or two sticks pressing the skin at various distances) were noted. Standard venous testing was accomplished if the possibility of deep venous thrombi (the only absolute contraindication to boot therapy) or if the diagnosis of stasis disease was considered. Then venous outflow studies, Doppler flow curves, venous reflux studies and, on rare occasions, more expensive venous Duplex scans were accomplished. Patients with palpable pedal pulses or biphasic Doppler waveforms in the foot and abnormalities in nerve function were listed as having a neuropathic basis for their lesions (e.g. ulcer or osteomyelitis). Those patients with low monophasic Doppler waveforms of the tibial vessels at the ankle, absent or low toe PPG’s, absent or faint Doppler sounds in the foot, transcutaneous PO2 values in the foot under 30 mm Hg, or a lack of continuous runoff into the foot on their arteriograms were listed as having ASO. Those patients with insensate feet and the above vascular abnormalities were listed as having combined ASO-neuropathy as the basis of  their lesions. Perhaps, because of the fact that the Circulator Boot was designed to treat arterial problems, patients with ASO were predominantly referred for treatment.

              Control Data from the “Other Leg”: Those patients presenting with symptoms limited to one leg provided “control data”. While baseline vascular studies commonly pointed to bilateral disease, insurance carriers commonly only pay for treatment of symptomatic disease. The asymptomatic leg was followed as a “control” and was treated only if symptomatic disease (e.g. ulcer, rest pain etc.) developed.

              Method of Result Classification: Patients who were cured or healed of their rest pain, claudication,  ulcer or osteomyelitis were listed as “healed”. Those whose pain was rendered tolerable, walking distance significantly improved or lesion clearly improved prior to death or loss-to-treatment were listed as “improved”.  Those who, after having been evaluated and started on treatment, left our care for any reason (advice of another physician, excessive travel distance, lack of transportation, slow progress, persistent pain or whatever)  were listed as lost-to-treatment, “LTT”. Those whose claudication improved to a lesser degree and leveled to a point where the patient was satisfied, although not entirely pleased, or whose black toe mummified and then changed little thus allowing normal life and modest walking were listed as “stable”. An attempt to amputate and heal such stabilized mummified toes was not made if vascular tests suggested nonhealing of the amputation. It may be noted that this group usually had improved one clinical category and might also have been labeled “improved” using the reporting criteria of the Ad Hoc Committee of the Society for Vascular Surgery (19).  Certain patients were treated for long periods of time in an unsatisfactory state but had few alternatives; they were listed as “chronic”. Those patients who came haphazardly for treatment and whose records were not clear were listed as “blank”. The other categories (“no help”, “slightly worse”, “AKA”, “BKA”, “?Benefit” and “Fails”) are self-explanatory.

              Author’s Recommended Criteria for Leg Amputation: Patients were encouraged to have leg amputations if they met one of three categories: (1) they asked to have their leg removed because of severe and persistent pain unresponsive to all of our therapies; (2) they had a spreading infection that was life threatening; (3) they had a foot so badly damaged that reasonable function was unlikely even if they did heal. No patient lost  leg  or life from spreading infection. Pain was the primary reason for amputation. Other physicians in attendance commonly recommended amputation on other criteria.

 

Results

Control Leg: Overall, treatment was initially begun on one leg in 671 patients; the other leg, if present, required no treatment in 411 patients and developed problems requiring treatment in 260, Table I. Thus,

 

Table I

The Fate of the Other Leg as Control Data

                                              Initial Treatments                                                      Control Legs

                                   ____________________________________________________________________________

                                        1-Leg Only         Both Legs                   Initial           Remain Intact          Breakdown

 

Males, All                               207                     268                            348                     198*                  150(43.1%)          

Females, All                            221                     394                            323                    213*                 110(34.1%)

    Total, all                              429                     962                            671                    411                   260(38.7%)

 

Males, ASO                            138                     376                            239                    129*     110(46.0%)

Females, ASO                         145                     218                            205                      137*                     68(33.1%)

    Total, ASO                         283                     594                            444                      266                     178(40.0%)        

 

Males, Neur                            37                       44                               93                        37                       56(60.2%)

Females, Neur                         29                       18                               47                        29                       18(38.3%)

    Total, Neur                         66                       62                             140                        66                       74(52.9%)

 

Males, Sts                               17                       42                                25                       17                         8(32.0%)

Females, Sts                            37                       40                                51                       37                       14(27.4%)

    Total, StsT                           54                       82                                76                       54                     22(28.9%)

*Not including previous AKAs or BKAs (male 9, female 8).     TIncludes 21 diabetic legs.

AKA = above knee amputation,  BKA = below knee amputation,  ASO = arteriosclerosis obliterans,

Neur = neuropathy,  Sts = stasis disease.

 

 

 of 671 “control legs”, disease progressed enough to require treatment in 260 or 38.7%. Broken down into disease category,  progression of the “control” leg was seen in 40% of ASO cases, 52.9% of neuropathy cases and 28.9% of stasis cases. It was expected that the fate of the presenting leg would be related to the balance of the natural progression of disease (as seen in our “controls”) and the effectiveness of the therapeutic program. If the latter had only a “placebo effect”, our treated legs might be expected to deteriorate in 28.9-52% of cases or more in view of the established and chronically progressive nature of the lesions referred for treatment. As spontaneous improvement in the “control” legs was not seen, the status of the “control” legs not deteriorating might be considered “stable” or “chronic” for 48-71.1% of legs. Against these rates of deterioration and stable-to-chronic states, Chi square determinations in the tables that follow are extremely high (e.g. 1188.8 for the initial results in TableV) and the success of our treatments is highly significant in all disease classes (P<0.001).

                The Wagner class in the presenting leg was in general a guide as to the kind of problem expected  in the good of “control” leg. Thus, among 89 men with a Wagner “0” classification in the bad leg, the “control” leg also became a Wagner “0” in 71 while 4 each developed problems in the Wagner “1”, “2” and “4” classes and 1 each developed lesions in the Wagner “3” and “5” classes. Again, among 49 men with an initial Wagner “4” classification in the bad leg, the “control” leg developed problems in the Wagner “0” class in 7 legs,  in the Wagner “1” class in 1 leg, in the Wagner “2” in 2 legs, in the Wagner “3” in 1 leg, in the Wagner “4” in 25 legs, in the Wagner “5” in 5 legs and in the unclassified category in 8 legs.    

Effect of Source of Patients: The flow of patients to our program is summarized in Figure 1. The largest single source of referrals was satisfied patients and their families. The number of legs from each source and the number of resulting major amputations associated with that source are also given in Figure 1. Overall, 8.36% of legs from all sources were eventually amputated. Significant differences above this average were vascular surgeons 19.1% (P<0.001) and general surgeons 22.7% (P<0.001 but a small sample).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Duration of Chief Complaint at Time of Presentation for Boot Therapy:  In Table II, the duration of the previous therapies is shown for each Wagner classification for the 1136 legs for which the data was available. Overall, 7.4% of legs presented within the first week of their illness; 64.9% had their problems more than two months and 26.7% had them a year or more. In the most numerous class, Wagner “0”, 33.5%  had their problems two or more years.

Table II

Duration of Chief  Complaint

at Time of Presentation for Boot Therapy

Wagner              0              1              2              3              4              5   

# Patients         394            213           159              95            212            63

<= 7 days       5.58%        9.39%        4.40%        8.42%       8.49%      14.29%          

8-30 days      11.68%      18.30%      19.50%      12.63%     20.75%      25.40% 

31-60 days      5.33%      14.55%      15.09%      10.53%     16.98%        7.94%

2-6 mos          17.77%      29.58%      23.27%      32.63%     28.30%      30.16%

6-12 mos        13.96%      11.74%      16.98%      13.68%     12.74%        9.52%

1-2 yrs            12.18%        9.39%       8.18%      10.53%       4.25%        4.76%

> 2 yrs            33.50%        7.04%      12.58%     11.58%       8.49%        7.94%

 

               

Table III

Early Results for Legs Started on boot within 14 Days

Result:   Healed  Improved   Stable     LTT   No Change   Blank      AKA     BKA   

Males          63             34              6              2                1                1              2*           0

Females      33             27              2              3                 -                3              4e            1**

     *  Sudden occlusion of bilateral aortofemoral bypasses

     ** Consulted but decides against boot therapy and never treated.

     e One patient with Wagner 5 foot after 3 vascular procedures; two renal dialysis patients, one with a

        Wagner 2 and the other a Wagner 4 foot; one patient with rheumatoid vasculitis and an infected 

        prosthesis.

 

The early effect of treatment in patients referred within fourteen days of the onset of their problem are shown in Table III. Two men, who had AKA’s, were poor candidates for boot therapy in that they had no arterial inflow at the groin. Two females with advanced arteriosclerosis obliterans had  AKA’s having boot treatments but 2 to 3 days a week while receiving dialysis on other days. Overall, the group did well while in our care. Nine patients had late major amputations: four females under the care of their referring physicians elsewhere and one female after a second relapse; three males under the care of physicians in other institutions and one male, after a fall and broken leg, in the care of his lawyer. Eventually, 16 of the 182 patients (8.79%) came to major amputations, a rate similar to the overall rate noted above.

Number of Legs Treated and Relapsing: Of 1038 patients, 609 had two legs treated (1218 legs) and 429 had one leg treated for a total of 1647 treated legs (Figure 2). Relapses occurred in 356 (21.6%). A second relapse occurred in 121 legs (7.3%). A third relapse occurred in 54 legs (3.3%). The sum of the initial treatments and relapses constitute the 2177 episodes described in this report. In Table IV,  the legs are classified when possible according to their predominant pathology and the percentages of legs having one, two or three relapses are shown. Compared to nondiabetic patients, both diabetic males and females with ASO were more likely to relapse (P<0.001). Male, but not female, patients with diabetic neuropathy were more likely to have an initial relapse than patients with ASO (P<0.05). If relapse did occur, both male and female patients with diabetic neuropathy were more likely to relapse a second time compared to patients with ASO (P<0.001).  Relapse was common in patients with stasis disease but not more so in those with diabetes (P<0.3). Most patients did well and did not relapse.

 

 

Table IV

Distribution of Treatments and Relapse Rates

Among Patients with ASO, Neuropathy and Stasis Disease

 Diabetes

    Sex

 Disease

 Number

    % 1st

    % 2nd

    % 3rd

   % Fate

   Status 

    M/F

   Type

  1st Rx

   Relapse

    Relapse

    Relapse

Elsewhere

    DM+

      M

   ASO

     400

  28.3*a

      9.75b

      5.0

    9.25

 

 

   Neur

     135

   38.5a

    15.6d

      5.2

    2.96

 

 

   Sts

       19

   42.1

    36.8

     10.5

  10.5

    DM+       

     F

   ASO

     256

   33.2**

    11.3c

       5.5

    0.78

 

 

   Neur

      64

   31.3

    18.8e

     10.9

    4.69

 

 

   Sts

      23

   34.8

      8.7

        0

   4.35

   DM-

    M

   ASO

    220

   11.8*

      3.6

        0

   8.18

 

 

   Sts

     44

   29.5

      6.8

       4.5

   4.54

   DM-

    F

   ASO

   180

   15.6**

      3.3

       1.6

   6.67

 

 

  Sts

     69

   27.5

    13.0

       8.7

   2.90

 

 

 

 

 

 

 

 

Chi Square for 1st Relapse: * P<0.001  ** P<0.001   a P<0.05

Chi Square for 2nd Relapse: b+c vs d+e P<0.001

 

 

Overall Initial Results among Patients Stratified by the Wagner Method: An overall summary giving the numbers of legs in each Wagner class and initial results of treatment by percentages for sex and diabetes state is given in Table 5. It is to be appreciated that it takes a patient and possibly hopeful observer to arrive at such excellent results. Blood flow is returned to the leg slowly by boot therapy; the blood must reach the ankle before it reaches the midfoot and the midfoot before it reaches the toes. In a leg at risk of amputation, toe lesions may worsen initially only to heal or autoamputate later as the leg is salvaged; such a leg is listed here as “healed”.  Leg salvage and maintenance of maximum function and independence were the goals of therapy. Autoamputations of gangrenous toes and eschar over bunions, for example, were not tabulated.

 

 

 

Table 5

Numbers of Legs and Percentage of Initial

 Wagner

    Sex

Diabetes

  Number

  Healed

Improved

  Stable

  Chronic

       0

      M

     N

    139

   2.9%

  72.7%

    6.5%

     0.7%

       0

      F

     N

    134

   3.7%

  78.4%

    2.2%

     0.0%

       0               

      M

     Y

    176

   1.7%

  81.8%

    6.8%

     0.0%

       0

      F

     Y

    116

   9.5%

  84.5%

    0.9%

     0.0%

 

 

 

 

 

 

 

 

      1

     M

     N

      47

 72.3%

  19.1%

    4.3%

     0.0%

      1

     F

     N

      75

 69.3%

  20.0%

    0.0%

     0.0%

      1

     M

     Y

      88

 88.6%

    4.5%

    2.3%

     0.0%

      1

     F

     Y

      62

 62.9%

  19.4%

    0.0%

     0.0%

 

 

 

 

 

 

 

 

      2

     M

     N

      37

 37.8%

  27.0%

  10.8%

     0.0%

      2

     F

     N

      32

 65.6%

  15.6%

    3.1%

     0.0%

      2

     M

     Y

      75

 69.3%

  18.7%

    2.7%

     0.0%

      2

     F

     Y

      58

 62.1%

  20.7%

    8.6%

     0.0%

 

 

 

 

 

 

 

 

      3

     M