Validity of the (WIFI) classification system in predicting the risk of amputation in patients with non healing ulcer

Validity  of  the  (WIFI)  classification  system  in  predicting  the  risk  of

amputation in patients with non healing ulcer

Wafi F. Salib,1 Atef A. Desokey,2 Ramez M. Wahba,2 Mohammed O. Zayed2

1Department of General Surgery, Ain Shams University, Egypt

2Department of Vascular Surgery, Ain Shams University, Egypt

Background: Classification systems are powerful tools for health care providers to use when managing patients with threatened limbs. The ability to define and delineate a heterogeneous group into fine-grained cohorts not only aids communication between providers, but also allows for a more accurate analysis of outcomes across treatment strategies. Thus, classification systems are essential for clinical decision making as well as setting meaningful goals and expectations with patients and their families.

Aim of the work: To evaluate the predicative ability of this classification in a real world selection at Ain Shams University at period of 1 year depending on the Society for Vascular Surgery, Classification depending on: Wound, Ischemia and Foot Infection (WIFI).

Patients and methods: This study included 60 patients with non-healing wound ulcer at Ain Shams University hospitals during year 2017 and 2018.

Results: As our study showed WIfI classification was predictive of 1 year limb amputation and wound non healing and correlated significantly with outcomes predicted by the SVS consensus panel. The study showed 1 year amputation rates were 0% for stage 1, 7.7% for stage 2, 18.75% for stage 3 And 64.7% for stage 4. It also showed among the 60 patients studied 15 patients had done amputations where 6.7% were stage 2, 20% were stage 3 and 73.7% were stage 4.

Conclusion: WIFI classification can be very useful in predicting the possibility of amputation during 1 year; also the

study showed the benefit of using WIFI to plan management of patients presented with foot ulcer.

Key words: WIFI classification system, amputation non-healing ulcer.

Introduction

Classification systems are powerful tools for health care providers to use when managing patients with threatened limbs. The ability to define and delineate a heterogeneous group into finegrained cohorts not only aids communication between providers, but also allows for a more accurate analysis of outcomes across treatment strategies. Thus, classification systems are essential for clinical decision making as well as setting meaningful goals and expectations with patients and their families.1

Old classification schemes fall short in capturing the full spectrum of disease for threatened limbs. The Fontaine and Rutherford classifications, commonly in use for threatened limbs and PAD, are purely ischemic models. Neither  classification  includes  infection  or  provides sufficient detail of wound severity.1

Similarly,  the  widely  used  Wagner  and  University of  Texas  wound  classification  systems  lack  proper assessment  of  perfusion  status  and  infection.  The Wagner system does not account for severity of PAD nor does it delineate gangrene due to infection versus

ischemia. The University of Texas system includes PAD and infection, but lacks severity gradation for either category.2

The  Society  for  Vascular  Surgery  Lower  Extremity Threatened  Limb  (SVS  WIFI)  classification  system has three components: Wound, Ischemia and Foot Infection. Each component is graded on a spectrum from 0 (none) to 1 (mild) to 2 (moderate) to 3 (severe) based on grades assigned to each of the three individual components, a WIFI class is assigned. Each Class is categorized  to  certain  stage:  Stage  1:  Amputation risk: very low, Stage 2: Amputation risk: low, Stage 3: Amputation risk: moderate, Stage 4: Amputation risk: high and Stage 5: Unsalvageable foot,3   The Society for Vascular Surgery WIfI system is intended for any patient with a diabetic foot ulcer, non-healing foot ulcer present for two or more weeks, foot/lower extremity gangrene, or ischemic rest pain. It is not meant for patients with acute ischemia, emboli, trauma, non- atherosclerotic diseases such as vasospastic disorders, or pure venous ulcers.

Wound:  The  first  category  accounts  for  the  degree

of tissue loss and anticipated level of intervention/

amputation required for healing.3

Ischemia: The second category assesses perfusion status to the foot using objective hemodynamic indices such as ankle brachial index (ABI), transcutaneous oximetry, pulse volume recording, skin perfusion pressure or toe pressure.3

Foot infection: The last category describes the foot infection and derives from the IDSA and

PEDIS clinical staging systems.3

Aim of the Work

The Society for Vascular Surgery; wound, ischemia and foot infection (WIFI) classification was proposed to  predict  amputation  risk  and  potential  benefit from revascularization. The goal of this study was to evaluate the predicative ability of this classification in a real world selection at Ain Shams University at a period of 1 year.

Patients and methods

Study setting: The study included patients with non- healing wound ulcer at Ain Shams University hospitals.

Study period: Patients with non-healing wound ulcer at Ain Shams University hospitals during year 2017 and

2018.

Study population: 60 patients with non-healing wound ulcer at Ain Shams University hospitals during year 2017 and 2018.

Inclusion criteria:

The Society for Vascular Surgery WIFI system is intended for any patient with:

1.   Diabetic foot ulcer.

2.   Non-healing foot ulcer present for two or more weeks.

3.   Foot/lower extremity gangrene, or ischemic rest

pain.

Exclusion criteria:

•    Critically ill patients.

•     Patients  with  acute  ischemia,  emboli,  trauma, non-atherosclerotic diseases such as vasospastic disorders, or pure venous ulcers.

Sampling method: Random sampling of patients Ain shams university hospitals.

Sample size: 60 patients.

Ethical Considerations:

According to approved standards to Ethical Committee of Ain Shams University.

Study tools

1. Complete history taking:

•    Age of presentation.

•     Medical habits e.g. smoker (number of packs per day and date starting smoking), Alcohol or drug.

•    intake.

•    Medical history  e.g.  DM,  HTN,  IHD,  history  of

Stroke, Renal or liver impairments.

•    Cause of wound and date wound appeared at foot.

2. Clinical evaluation and examination:

•    Amount of tissue loss and degree of infection.

•    Depth and size of wound.

•    Site of the wound.

•    Discharge from wound.

•    ABIusingVascularDopplerandSphygmomanometer.

3. Arterial duplex and CT angiography on arterial tree of both lower limbs if needed.

Statistical analysis: Data were collected, tabulated and propriety statistical analyses were applied such as Annova, t-Test, and Pearson Correlation.

Statistical package: Excel 2010, SPSS vers.24 and

N-Primer.

Results

Table 1

Demographics                                     Total no. = 60

Mean ± SD                                          59.22 ± 10.97

Age

Sex Smoking Cigarettes/d Cigarettes/m Obesity

DM HTN Hypercholesterolemia IHD

CHF CVA

Renal insufficiency

Range                                                 39 – 82

Male                                                    37 (61.7%) Female           23 (38.3%) No   48 (80.0%) Yes                                         12 (20.0%) Median (IQR)  20 (20 – 40) Range                                                          10 – 60

Median (IQR)                                       600 (600 – 1200) Range    300 – 1800

No                                                          50 (83.3%) Yes                                                         10 (16.7%) No                                                          0 (0.0%)

Yes                                                     60 (100.0%) No   29 (48.3%) Yes  31 (51.7%) No                                                      45 (75.0%) Yes    15 (25.0%) No   35 (58.3%) Yes                                                     25 (41.7%) No     60 (100.0%) Yes 0 (0.0%)

No                                                      56 (93.3%) Yes    4 (6.7%)

No                                                      54 (90.0%)

Yes                                                     6 (10.0%)

Table 2

Initial investigations                          Total no. = 60

Mean ± SD                                          11.40 ± 1.59

HGB

TLC PLT CRP ESR HbA1c Creat Alb INR

Range                                                 8.2 – 14.5

Mean ± SD                                           10.79 ± 3.76

Range                                                 5 – 20

Mean ± SD                                           334.15 ± 96.94

Range                                                 115 – 599

Median (IQR)                                       8 (6 – 18) Range  3.5 – 96

Mean ± SD                                           74.00 ± 32.24

Range                                                 20 – 140

Mean ± SD                                           8.52 ± 1.72

Range                                                 6 – 13.1

Mean ± SD                                           1.16 ± 0.95

Range                                                 0.6 – 7.5

Mean ± SD                                           3.35 ± 0.58

Range                                                 2 – 4.5

Mean ± SD                                           1.13 ± 0.11

Range                                                 0.9 – 1.3

As our study showed WIfI classification was predictive of 1 year limb amputation and wound non healing and correlated significantly with outcomes predicted by the SVS consensus panel.

The study was done on 60 patients, which all had Diabetes, from Ain Shams University Hospitals during period of 2017 and 2018 from which there were 23 female (38.3%) and 37 male (61.7%).

The study showed that the 1 year amputation rates were 0% for stage 1, 7.7% for stage 2, 18.75% for stage 3 and 64.7% for stage 4. It also showed among the 60 patients studied 15 patients had done amputations  where 6.7% were stage 2, 20% were stage 3 and 73.7% were stage 4.

Table 3: Percentage of amputations in each stage from total amputations performed in the study

WIFI Clinical stage                   Number of amputations done during 2017 and 2018

Percentage form total amputations

1                                                      0                                                        0%

2                                                      1                                                       6.7%

3                                                      3                                                       20%

4                                                     11                                                     73.3% All stages                                                   15                                                     100%

Table 4: Percentage of amputations from patients in each stage

Number of

Percentage of

WIFI Clinical stage            Number of patients

amputations done during 2017 and 2018

amputations in each stage

1                                       14                                       0                                            0

2                                       13                                       1                                        7.70%

3                                       16                                       3                                       18.75%

4                                       17                                       11                                       64.7%

Table 5: Patients subjected or not subjected to amputation in each stage

P-value > 0.05: Non significant; P-value < 0.05: Significant; P-value < 0.01: Highly significant *: Chisquare test.

Discussions

As our study showed WIfI classification was predictive of 1 year limb amputation and wound non healing and correlated significantly with outcomes predicted by the SVS consensus panel.

The study showed 1 year amputation rates were 0%

for stage 1

7.7% for stage 2

18.75% for stage 3

64.7% for stage 4

It also showed among the 60 patients studied 15 patients had done amputations where

6.7% were stage 2

20% were stage 3

73.7% were stage 4

The study shows the correlation between the 1 year

risk of amputation and the stage in WIFI classification.

In comparison to the studies done by Nestoras Mathioudakis, MD, et al. J Vasc Surg 2017 which showed major amputations continued to plague the most severe stage 4 WIfI patients, with 1-year amputation rates of

20% to 64% among patients with diabetic foot ulcers

(DFUs) treated in a multidisciplinary setting.1

In this study There were 217 DFU patients with 439 wounds (mean age, 58.3 6 0.8 years; 58% male, 63% black) enrolled, including 28% WIfI stage 1, 11% stage

2, 33% stage 3, and 28% stage 4.1

Minor amputations where 18 % in stage1 and 56% in stage 4. Major amputation at 1 year.1

Moreover this study showed peripheral arterial disease and dialysis were more common in patients

with advanced (stage 3 or 4) wounds (P # .05). Demographics of the patients, socioeconomic status, and comorbidities were otherwise similar between groups.

This  supports  that  the  WifI  classification  system

correlated risk of major amputation at 1 year.

However; use of a multidisciplinary approach for DFUs may augment healing time and reduce amputation risk compared with previously published historical controls of standard wound care among patients with advanced stage 4 disease.

Another study done by Joseph L.Mills Sr 2014 ElsevierInc showed three single-center studies validating the underlying premises and basic concept of the SVS WIfI Threatened Limb Classification System.3

The  Greenville  group  recently  reported  the  results of  158  revascularization  procedures  performed  in

139 patients during a 3-year period and classified patients after revascularization based on the SVS WIfI classification. The WIfI clinical stage was predictive of major limb amputation and wound non

healing  and  correlated  significantly  with  outcomes

predicted by the SVS consensus panel.3

The  reported  major  amputation  rates  were  3%,

10%, 23% and 40% for clinical stages 1, 2, 3 and 4 respectively. The corresponding wound nonhealing rates were 8%, 19%, 30% and 63% as one progressed from clinical stage1 up to clinical stage 4.

It should be noted that this group applied the SVS WIfI classification after revascularization which would be analogous so the results most applicable to patients with more severe grades of ischemia.

The University of Arizona group prospectively applied SVS WIfI classification to a group of 201 consecutive patients presenting with threatened limbs during a

2-year period. All patients had wounds at presentation, and 93% of the total cohort had diabetes mellitus.3

WifI classifications were calculated at baseline, before initiation of any treatment, and included patients with a broad spectrum of wounds and ischemia and a significant number with infection.

No patients in clinical stage 1 and 2 required amputation,

10% of the amputations were in clinical

stage3 patients and 90% were in clinical stage 4.

One-year amputation free survival rates were 100%for clinical stages 1 and 2, 92% for clinical stage 3 and dropped to 63% for clinical stage 4.

Wound healing time was also found to correlate strongly with clinical stage, progressively increasing with each clinical stage, ranging from 94 days in clinical stage1 to 264 days for clinical stage4. There was a significant difference  between  mean  wound  healing  time  of stage 1 and 3 patients (P ¼ .048). However, the most significant delay of wound healing was in stage4 (263 days, 95% confidence interval, 167_360) compared to clinical stages 1 to 3 (P0.002).

Revascularization resulted in a profoundly accelerated wound healing time, especially in clinical stage3 patients (P ¼ .008).

The University of California (San Francisco) group prospectively applied SVS WifI classification to 63 threatened limbs in 50patients, 70% were diabetic.3

No limbs in stage1 or 2 patients required amputation, but both minor and major amputation rates increased in stage3 (19% and 6%) and stage 4 patients (59% and 24%), respectively (P ¼ .01).3

Wound score and infection score were associated with major amputation, but baseline comorbidities were not.

Ischemia  score  did  not  correlate  with  amputation risk in this series, but the revascularization approach was aggressive and nearly all revascularizations were successful.

Those 3 studies supported furthermore the predicitive ability of WIFI classification in determining 1 year amputation rates. Also they showed that WIFI correlated with wound non healing and how revascularization decrease the risk of amputation and time of wound healing.

Also; in 2014, Cull et al17  examined and graded 139 patients with foot wounds undergoing any lower extremity revascularization and concluded that increases in the WIfI clinical stages correlate with poorer wound healing and lower rates of 1-year limb salvage.4

Similarly, in 2015, Zhan et al evaluated 201 patients