Influence of gene polymorphisms in ulcer healing process after superficial venous surgery
Article Outline
Objective
Role of superficial venous surgery in reducing the time it takes for ulcers to heal is still controversial, although all studies confirm a significant reduction in ulcer recurrences. Recently, the HFE-C282Y and FXIII-V34L gene variants demonstrated a role in the risk of venous ulceration in primary chronic venous disorder (CVD) and in modulating lesion size in chronic venous ulcer (CVU), respectively. This study was conducted to investigate the role of HFE-C282Y and FXIII (V34L and P564L) gene variants in ulcer healing time after superficial venous surgery, by assessing the outcome of a cohort of homogeneous CVU patients.
Methods
The study selected 91 patients affected by primary CVU (CEAP C6, Ep, Asp, Pr), with the exclusion of any other comorbidity factor involved in delayed healing process, who underwent surgery. We assessed the ulcer area and the healing time. Patients were genotyped by polymerase chain reaction for FXIII (V34L and P564L) and for HFE-C282Y substitutions.
Results
Globally, CVU cases had a postoperative mean healing time of 8.5 ± 5.7 weeks. For the subset of cases above and below the median value (M = 8.0 weeks), FXIII-V34L genotype distribution significantly differed (P < .0001). In addition, Kaplan-Meier analysis yielded specific healing time profiles for the different FXIII-V34L classes of genotype (P = .00001), with an increased risk of delayed healing for the FXIII-VV genotype (hazard ratio, 4.14; 95% confidence interval, 2.1 to 8.2; P = .00005). Although FXIII-P54L genotype distributions did not differ, homozygous 564LL cases (P = .005) and double carriers for both FXIII variants (P < .0001), had a significantly reduced healing time vs wild types. No differences in healing time were observed between carriers and noncarriers of the HFE-C282Y variant, whereas when these cases were stratified by FXIII-V34L genotypes, the L34 carriers had a significantly shorter healing time, irrespective of the HFE genotype.
Conclusion
The FXIII-34L variant was significantly associated with shorter healing time after superficial venous surgery, suggesting a role in the healing and tissue regeneration phases. Conversely, HFE-C282Y, despite its role in ulcer establishment, did not affect the postoperative healing time. In perspective, the identification of patients with a poor prognosis may give clinicians the opportunity to modify management and to target tailored therapies in the view of a new and alternative concept of treatment based on pharmacogenomics.
Chronic venous leg ulcers (CVU), account for a significant proportion of lower extremity wounds. CVU is a severe clinical manifestation of chronic venous disease (CVD), a widespread pathologic condition in developed countries.1, 2 CVD accounts for about 70% of CVU, and although it is an essential comorbidity factor, it is insufficient for skin lesion appearance.2, 3, 4 The prevalence of CVU in the United States and Europe is 0.5% to 2.0%, with very high health-service and socioeconomic costs owing to the frequent recurrences and repercussions on the patients’ capabilities to work.5
The treatment of choice for CVU is compression bandaging combined with wound bed preparation. For those patients who do not improve with conventional care, skin grafting or biologic dressing are useful.2, 6 Whilst it is controversial if the addition of superficial venous reflux correction by surgery has positive effects in reducing ulcer healing time, there is wider agreement in the associated reduction of recurrences.7, 8 The Comparison of Surgery and Compression with Compression Alone in Chronic Venous Ulceration (ESCHAR) study compared healing and recurrence rates in CVU patients treated with compression, with or without surgery.9 It concluded that superficial venous surgery confers no added benefit over compression in healing rate but does lead to a reduction in recurrence, according to other nonrandomized studies.8
A recent systematic review that evaluated the overall rates of clinical outcomes in patients with severe CVD concluded that surgery, subfacial endoscopic perforator surgery included, with or without saphenous ablation, leads to an 88% chance of ulcer healing and a 13% chance of recurrence.10 The authors concluded that randomized controlled trials were needed to define the effective contributors of compression, superficial surgery, and subfacial endoscopic perforator surgery in CVU treatment.
Finally, we published a randomized study that compared the effects on healing of minimally invasive surgical intervention vs compression, exclusively reserved for patients affected by primary and superficial venous reflux and in absence of other significant comorbidities.11 We concluded that this kind of hemodynamic correction, respecting the proposed indications, improves healing even in terms of time, recurrence, and hemodynamics.
Regardless of the clinical strategy, a great variation exists in the clinical outcome among patients with similar disease pattern and treatment. Owing to the multifactorial etiology of longstanding ulcer, recognizing appropriate risk factors affecting healing may be a choice strategy to early select those patients that will have an unfavorable outcome. A recent study identified among a number of routinely assessed variables, increased patient age and ulcer chronicity, and slow healing time, but not surgically treated superficial venous reflux, as independent risk factors, respectively, for healing and recurrence.12 In addition, larger wound area, duration of the wound, and fibrin on >50% of the lesion surface were associated with failure to heal.13 Other good candidate risk factors, such as diabetes, rheumatoid arthritis, or popliteal vein incompetence, were not found to be significantly associated.12 This clarifies the current lack of understanding in venous ulcer pathogenesis. On the other hand, many patients with CVD do not progress towards skin lesion, suggesting that interindividual variability is warranted. Genetics may have a role in subject individuality, although evidences for this and for a mode of inheritance are lacking.
We recently recognized that the common gene polymorphisms HFE-C282Y and FXIII-V34L have a role, respectively, in increasing the risk of venous ulceration by establishing local iron overload in primary CVD patients,14, 15 and in modulating the lesion size by means of positive effects on fibroblast cells and extracellular matrix components in CVU patients.16
The HFE-C282Y variant in the coding region of the hemochromatosis gene affects iron metabolism. Heterozygous subjects are generally considered asymptomatic carriers unless other inherited or acquired conditions may contextually determine iron overload.17
FXIII-V34L, in the coding region of the coagulation factor XIII gene, significantly increased the transglutaminase activity of the molecule in a gene-dosage effect. Basically, the FXIII-V34L variant decreases the risk of thrombosis, and recent in vitro and in vivo studies ascribed to FXIII, or to its variants, a key role in wound healing, tissue repairing/remodelling and angiogenesis.18 Other FXIII gene variants, such as FXIII-P564L, may affect the molecule properties, but very few and conflicting data have been reported.19 Therefore, in the present study we investigated whether these recognized gene factors might have effects on the healing time of CVU patients after superficial venous surgery.
Patients and methods
Patient population
We studied 91 patients (65% women) with a mean age of 60.5 ± 14.5 years who were affected by primary CVU involving exclusively the superficial and perforator vein system. Patients were selected from an initial cohort of 215 patients referred to our Vascular Diseases Center. For the purpose of patient selection, these patients had a clinical history recorded and a duplex scanning examination. These investigations, conducted in accordance with consensus statement criteria and a methodology previously described,11, 22, 23 allowed us to carefully separate primary superficial from secondary cases, and within the latter, those affected by post-thrombotic venous insufficiency, and also to identify patients with peripheral arterial disease.
The following exclusion criteria for patient selection were strictly applied to exclude any other comorbidity factor that might potentially be involved in delayed wound healing: diabetes, peripheral arterial disease or an ankle-brachial index <0.9, or both; hemolytic anemia, iron-deficiency anemia, or malnutrition; inability to walk, severe cardiac, hepatic, renal, or pulmonary insufficiency; long-term administration of cortisones for chronic inflammatory disease or autoimmune disease, duration of the skin lesion <6-months, and post-thrombotic syndrome.
After applying the criteria, 91 patients were selected, described by the following CEAP algorithm:C6s, Ep, As2 3 4 5-p 17 18, Pr. The area of the ulcer was digitally acquired and then assessed by means of software that was able to calculate any irregular area (Visitrak Capture, Smith & Nephew, London, UK). Finally, patients underwent preoperative air plethysmography assessment of venous function.
Surgical treatment
The selected patients underwent hemodynamic correction of superficial venous reflux according to a technique previously reported and validated by a long-term randomized trial of venous ulcer treatment.11 On admission, the operation was planned for a week later and the patients, while waiting, were immediately treated with compression bandaging. Operations were performed in the Day-Surgery Unit with local anesthesia and required preoperative duplex mapping. Surgical débridement was performed in the same session.
In the case of patients with infected wounds, the antimicrobial susceptibility test was ordered and wide-spectrum antibiotics were administered; they were replaced after 5 days by a specific antibiotic as indicated by the test results.
The primary cover of the ulcer was an advanced dressing (Actisorb plus 25, Johnson & Johnson, Berkshire, UK, or Hyalofil, Fidia Advanced Biopolymers [FAB], Padova Italy). The bandaging was changed every 3 to 5 days during the first month of treatment and then every 7 days. Once the ulcers were healed, the patients were fitted for elastic stockings exerting 20 to 30 mm Hg of compression at the ankle.
Surgical procedure details
Two different minimally invasive techniques were performed, according to the location of the superficial opening of the re-entry perforator vein (RPV). The RPV is defined as a perforator in which finger compression above its opening is able to eliminate the reflux wave in the saphenous trunk. Such an opening can be located either on the long saphenous vein-short saphenous vein main trunk (type I shunt) or on a long saphenous vein-short saphenous vein tributary (type II shunt). A duplex assessment, which was performed for both procedures, can easily differentiate between the two main hemodynamic presentations.20, 21
The operation for the type I presentation was a classic high ligation of the saphenofemoral junction or saphenopopliteal junction plus flush ligation and division from saphenous trunk of the insufficient T (Fig 1, A). It was performed in 72 cases (79.1%). Patients began to walk 1 hour after the procedure. The ulcer was covered by an advanced dressing, and the patient wore an elastic stocking exerting 20-30 mm Hg of ankle pressure.
Fig 1.
A, Hemodynamic correction procedure performed for type I presentation. Left panel: reflux from the saphenofemoral junction (SFJ) flows downward along the main saphenous trunk (GSV) to the varicose tributary (T) and to the re-entry perforating vein (RPV). Right panel: operation consisted in flush legation and disconnection of the GSV from the femoral vein, and of the T from the GSV. We eliminated in this way the reflux point with change of compartments from deep to saphenous compartment, and from saphenous compartment to the superficial one, respectively. In the GSV, we so obtained a reverse flow from the junction to the RPV, and a forward flow from the foot to the RPV. Air-plethysmography parameters assessed the effectiveness of the procedure.20 B. Hemodynamic correction procedure performed for type II presentation. Left panel: reflux from the SFJ flows downward along the GSV to the T without re-entry perforating vein detectable along the GSV. Right panel: operation consisted in flush legation and disconnection of the T from the GSV. In the GSV, we also obtained a forward flow. Air-plethysmography parameters assessed the effectiveness of the procedure.21
The operation for the type II presentation was a flush ligation and division from the saphenous trunk of the insufficient T, which contains the RPV (Fig 1, B). The postoperative course was the same as described for the type I shunt.
Measurements
The clinical result assessment was made in a blinded fashion to the genotype of patients and according to the following parameters:
C).
DNA analysis
Genomic DNA was isolated from peripheral blood by using standard proteinase-K treatment, followed by phenol-chloroform extraction and ethanol precipitation. Polymerase chain reaction was used to genotype samples for FXIII-V34L, FXIII-P564L, and HFE-C282Y gene variants according to previous reports.24, 25, 26 Genotypes were confirmed by re-genotyping a random selection of samples for each polymorphism investigated. No discrepancies were found between genotypes determined in duplicate. Genotyping was done in a blinded fashion relative to the clinical phenotype and the healing progress of patients.
Statistical analysis
The statistical significance for the differences between case groups was performed by Student’s t test for parametric data and χ2 for nonparametric data. Where appropriate, the Yates correction or Fisher’s exact test was applied. P ≤ .05 was considered statistically significant. To estimate the risk of having a poor clinical outcome in terms of healing time greater than the median value, hazard risk (HR) and 95% confidence intervals (95% CI) were calculated between different classes of genotypes by means of Cox proportionate hazards modeling, with and without the enclosure of confounding factors such as sex, age, and mutual genotype adjustments. Healing time profiles for cases with different classes of genotype were similarly obtained by Kaplan-Meier analysis, and differences were determined by using a log-rank test. All analyses were performed with Systat 5.0 (Systat Inc, Evanston, Ill) and the SPSS 10.1 statistical software (SPSS Inc, Chicago, Ill).
Results
Clinical results
The 91 ulcerated lower extremities that were related to a primary and superficial venous disorder had the hemodynamic correction procedure in our Day-Surgery Unit. Patients were discharged ≤3 hours and were seen twice a week for the first week and then weekly until the ulcer was healed. Patient follow-up lasted about 6 months. The healing rate was 100% in the 6-month period.
Duplex assessment
Duplex imaging allowed the correctness of the operations for type I and type II presentations to be assessed according to the schema presented in Fig 1, A and B.
Venous function
All the APG parameters (VV, VFI, and RVF), with the exception of EF, significantly improved 6 months after the operation, confirming the surgical restoration of venous hemodynamics (Table I).
Table I. Air-plethysmography parameter assessment
| APG assessment | VV mL/air | VFI mL/s | EF % of VV | RVF % of VV |
|---|---|---|---|---|
| Pre-op | 170±54.6 | 6.7±3.4 | 48±12.5 | 40±15.7 |
| 6 months post-op | 134±44.1⁎ | 3.0±51⁎ | 57.0±18.1 | 29±15.1⁎ |
| (−25%) | (−44%) | (−31%) |
⁎ Postoperative parameters significantly different compared with preoperative assessments (P < .001). |
FXIII-V34L and FXIII-P564L gene variants and ulcer healing time
Table II summarizes the genotype distribution of the FXIII- and HFE- gene polymorphisms stratified above and below the median healing time value of 8 weeks. The FXIII-V34L distribution was significantly different (P < .0001), accounting for the significant overrepresentation of L34 carriers found in patients with shorter healing times (27/39, 69.3%) vs those with longer healing times (16/52, 30.7%, P <.0001) (Fig 2). In explorative analysis, this yielded an overall crude estimate of the risk to have a delayed healing time of about five times for the VV34 genotype vs L34 carriers in our population (HR, 5.06; 95% CI, 2.06 to 12.4; P < .0001). When confounding variables and the other gene variants were entered in the Cox regression model, the risk estimate did not change the output (HR, 4.14; 95% CI, 2.08 to 8.23; P < .0001).
Table II. Comparison of polymorphism genotype distributions between chronic venous ulcer patients with healing time above and below the median value.
| FXIII-V34L | P | FXIII-P564L | P | HFE-C282Y | P | |||
|---|---|---|---|---|---|---|---|---|
| HT ≥M (n=52) | HT ≥M (n=52) | HT ≥M (n=52) | ||||||
| VV | 36(69.2) | PP | 29(55.7) | CC | 47(90.4) | |||
| VL | 11(21.1) | PL | 21(40.4) | CY | 5(9.6) | |||
| LL | 5(9.6) | LL | 2(3.8) | YY | 0(0) | |||
| HT < M (n = 39) | <.0001 | HT < M (n = 39) | .29 | HT < M (n = 39) | .885 | |||
| VV | 12(30.7) | PP | 24(61.5) | CC | 34(87.2) | |||
| VL | 24(61.5) | PL | 11(28.2) | CY | 5(12.8) | |||
| LL | 3(7.7) | LL | 4(10.2) | YY | 0(0) | |||
Fig 2.
Healing time and FXIII-V34L polymorphism distribution in the whole cohort of patients with chronic venous ulcer investigated in the study. L34 carriers indicate cases with FXIII-VL34 or FXIII-LL34 genotype. The line indicates a median healing time of eight weeks. The P value indicates the statistical significance between the percentage of FXIII-L34 carriers in cases with healing time above and below the median.
The evaluation for differences in the healing time profiles for the two classes of FXIII-V34L genotype was done by Kaplan-Meier analysis. It showed significant differences and ascribed to the FXIII-VV genotype the worst clinical outcome in terms of greater percentage of cases with healing times above the median (log-rank test, P = .00001) (Fig 3). No significantly different distributions were found with the FXIII-P564L gene variant.
Fig 3.
Kaplan-Meier analysis for chronic venous ulcer patients stratified by FXIII-V34L genotypes (log-rank test, P =.00001).
Together with the significant overrepresentation in the number of L34 carriers found in the group with healing times below the median, a significantly shorter mean healing time was also found in the L-34 carrier group (ie, 6.2 ± 3.4 weeks vs 10.6 ± 6.5 weeks, P < .0001, respectively, for the L34 and the VV34 carriers; see Table III). In these two subgroups of patients, we also assessed the dimension of the ulcer area, and as expected, we found that it was significantly smaller in the L34 carriers than in the VV34 carriers (6.0 ± 6.2 cm2 vs 13.1 ± 24.5 cm2, P = .029; respectively; see Table III).
Table III. Healing time and ulcer area dimension in the whole cohort of cases stratified by FXIII genotypes
| FXIII Variant | FXIII genotype | n | HT weeks | Ulcer area (cm2) | P⁎ | P† |
|---|---|---|---|---|---|---|
| FXIII-V34L | VV | 48 | 10.6±6.5 | 13.1±24.5 | <.0001 | 0.029 |
| VL+LL | 43 | 6.2±3.4 | 6.0±6.2 | |||
| FXIII-P564L | PP | 53 | 8.9±6.2 | 12.0±23.4 | 0.19 | 0.064 |
| PL+LL | 38 | 7.8±4.7 | 6.7±7.0 | |||
| Total | 91 | 8.5±5.7 | 9.7±18.5 |
⁎ Healing time (HT) comparison. |
† Ulcer area comparison. |
Results with a similar trend were found with the FXIII-P564L gene polymorphism but with nonsignificant or borderline values (Table III). In explorative analysis computing merely the 564LL homozygotes, they had both mean healing time (5.7 ± 1.9 weeks, P = .005) and ulcer area (2.83 ± 1.3 cm2, P = .003) significantly lower than that found in the wild types (data not shown).
To minimize the predictable effects of ulcer dimension on healing time and to better assess and define the effective genotype contribution, we considered patients above and below the median healing time as two separate groups. We found significant results only in the subgroup with a larger ulcer area. In particular, patients with the VV34 or PP564 genotype had the longer healing time (Table IV, top). It is noteworthy that also in the absence of significant differences in mean ulcer size between patients with the FXIII-V34L genotype (P = .08), patients carrying the L34 allele had a significantly shorter healing time (P = .017; see Table IV, top). With the FXIII-P564L variant, borderline significant values were obtained between different genotypes for both mean healing time and ulcer size (Table IV, top). Conversely, absolutely no significant results or trend were obtained in the group with smaller ulcer area (Table IV, bottom). Fig 4 clearly summarizes the relationships between mean healing time and different FXIII genotypes.
Table IV. Healing time and ulcer area dimension in cases with healing time above and below the median value stratified by FXIII genotypes
| FXIII variant | FXIII genotype | n | HT weeks | Ulcer area (cm2) | P⁎ | P† |
|---|---|---|---|---|---|---|
| HT ≥ median value (8.0 weeks) | ||||||
| FXIII-V34L | VV | 36 | 12.5±6.2 | 16.5±21.7 | 0.017 | 0.08 |
| VL+LL | 16 | 9.5±3.4 | 9.6±8.3 | |||
| FXIII-P564L | PP | 29 | 12.7±6.0 | 19.0±30.2 | 0.051 | 0.043 |
| PL+LL | 23 | 10.2±4.9 | 8.9±8.6 | |||
| Total | 52 | 11.6±5.6 | 14.4±23.5 | |||
| HT < median value (8.0 weeks) | ||||||
| FXIII-V34L | VV | 12 | 4.3±0.7 | 4.1±3.2 | 0.33 | 0.23 |
| VL+LL | 27 | 4.0±0.1 | 3.4±1.7 | |||
| FXIIIP-564L | PP | 24 | 4.0±0.4 | 3.6±2.5 | 0.37 | 0.42 |
| PL+LL | 15 | 4.1±0.5 | 3.7±1.9 | |||
| Total | 39 | 4.1±0.5 | 3.61±2.3 |
⁎ Healing time (HT) comparison. |
† Ulcer area comparison. |
Fig 4.
Relationships between mean healing time and different FXIII genotypes. The whole cohort of patients with chronic venous ulcers is shown and the subgroups carrying the FXIII-V34L and FXIII-P564L genotypes. L34 carriers indicate patients with FXIII-VL34 or FXIII-LL34 genotype, and L564 carriers indicate patients with the FXIII-PL564 or FXIII-LL564 genotype. The lines and values shown indicate the different mean healing times and standard deviation. P values indicate the statistical significance between mean healing times for each specific FXIII genotype.
In addition, to investigate possible combined effects on healing time of the two FXIII gene polymorphisms, the 18 subjects carrying both gene variants were compared with the 28 subjects null for both the polymorphic alleles. The different healing time distributions of the two subgroups of cases are shown in Fig 5, with significantly shorter mean healing times found in double carriers compared with wild types (5.8 ± 2.1 weeks vs 10.9 ± 6.9 weeks, P < .0001).
Fig 5.
Healing time distribution in two subgroups of patients with chronic venous ulcers carrying the FXIII-VV34/PP564 double wild type (WT) genotype, and the FXIII-VL/LL34+PL/LL564 genotype (double carriers), respectively. The line and value shown indicate the different mean healing times and standard deviation. The P value indicates the statistical significance between the two mean healing times.
HFE-C282Y gene variant and ulcer healing time
The genotype distribution of the HFE gene polymorphism stratified above and below the median healing time was not significantly different (Table II). Similarly, the mean healing time and the mean ulcer area were both nonsignificantly different comparing HFE-C282Y carriers vs noncarriers in the whole group of cases, as well as in the subset groups that were analyzed (data not shown). Finally, stratifying these cases by FXIII-V34L genotypes, the L34 carriers conserved the significative shorter healing time, irrespective of the HFE-C282Y genotype (Table V).
Table V. Combined effects of HFE-C282Y and FXIII-V34L polymorphism on ulcer healing time
| HFEC282Y (n = 91) | FXIII-V34L healing time (weeks) | P | |
|---|---|---|---|
| VV | VL+LL | ||
| CC | 10.1±6.2 | 6.44±3.9 | .0014 |
| n = 81 (89%) | n=45 | n=36 | |
| CY | 14.6±10 | 7.4±5.8 | .08 |
| n = 10 (11%) | n=3 | n=7 | |
Discussion
Many of the limitations in the treatment of CVU are due to the lack of knowledge of molecular wound healing mechanisms. To identify a number of independent inherited or required risk factors responsible for chronic wound pathogenesis is an essential step for the diagnosis and prevention of such a complex disease and for the design of new treatment strategies as alternatives or ancillary to the standard procedures. Apart from CVD, increasing age and female gender,2, 3, 4 clear evidences for genetic predisposition to CVU are still limited. Candidate genes may be those involved in inflammatory processes, fibroblast growth factors, angiogenesis, or apoptosis. Very few data on single nucleotide polymorphisms and CVU are available in the literature.27, 28, 29 We recently recognized that the common single nucleotide polymorphisms HFE-C282Y and FXIII-V34L have a role, respectively, in the risk of venous ulceration in primary CVD and in the modulation of the lesion size of CVU patients.14, 15, 16
The main finding of our study was that among our cohort of patients affected by primary CVU who underwent superficial venous surgery, the FXIII-VV34 genotype was a predictor for poor clinical outcome in terms of longer healing time, and confirmed also in combination with the FXIII-PP564 genotype. In explorative monovariate analysis, the risk was about five times (odds ratio, 5.0; 95% CI, 2.06 to 12.4) for VV34 patients, and it also remained significant in multivariate analysis (HR, 4.14; 95% CI, 2.08 to 8.23).
We also found that those patients had a larger wound area, a risk factor previously described as being associated with failure of wounds to heal.13 In that study, authors observed that the failure of a wound to heal ≤24 weeks of limb compression was associated with the initial area of the lesion along with other risk factors. This could partly affect our findings. However, the clearly significant shorter healing time (P = .017) in the cohort of our patients who were L34 carriers, also in the presence of nonsignificant different mean wound areas between the opposite genotypes (P = .08), improves our outcome.
On the other hand, the protective role of this gene marker was evident only in the larger lesions, which could partly be explained by the coexistence in the smaller wounds of whole constellations of stronger and unknown protective factors or lack stronger risk factors. Both of these situations might simply overcome the gene marker role. Conversely, larger wounds might possess biologic agents that may inhibit wound healing but also prevent systemic infections, and thus, the individual escapes systematic illness.13 All of this could allow the lesion to progress and the gene to fully express its action. Basically, this may have a clinical sense considering that a complete linear relationship does not exist between wound area and healing failure. The magnitude of the nonhealing risk initially increases rapidly for large wounds, but it diminishes with the largest ones.13
Also of importance is that all of the patients in our survey were completely hemodynamically corrected by surgery. Therefore, the essential but insufficient factor for skin lesion establishment was eliminated. This could account in part for the following objection: why a genetic factor (congenital by definition) should be protective (ie, FXIII-V34L on healing time) only after a lesion becomes larger and not prevent it from happening in the first place? Similarly, one could ask why a gene risk factor for ulcer establishment (ie, HFE-C282Y) did not affect healing time or lesion size in our survey of postoperative patients?
One answer can well explain both objections: once superficial venous reflux was corrected and a normal circulation was restored, many proliferating factors can reach the débrided wound. Among these, FXIII strengthens the extracellular matrix against unrestrained matrix metalloproteases proteolysis, favoring in turn fibroblast migration and proliferation and promoting neoangiogenesis and healing.15, 30, 31, 32, 33, 34 The quality and degree of these actions may be strictly dependent on the associated gene variants.16 It could be hypothesized that a significantly higher FXIII activity (ie, that of the L34 variant) at the wound site could better promote wound healing by improving the above-mentioned tasks and thus shortening the wound closure time. Contextually, a restored venous drainage gets rid of local iron overload, drastically lowering the possibility that HFE-mutated phagocytes, losing the ability to counteract the intracellular iron export, generate locally free iron and free radicals and leading to matrix breakdown and skin lesions.14, 15, 35 This would avoid both the detrimental effects of free radicals and hyper-proteolysis on extracellular matrix components contrasting, in turn, cell death.15, 31
Conclusions
Although the number of actors involved in the etiology of chronic wounds is extremely high and the above explanations may just partly account for the complex etiology of CVU, our study furnishes a good example of gene-gene and gene-environment interactions for this multifactorial disorder. Our results, for the first time, could pave the way to single out in advance categories of patients at increased risk and to address tailored strategies of treatment, such as priority for surgical correction of superficial venous reflux.
Future multicenter molecular investigations could identify groups of molecular markers responsible for chronic inhibition of a wound to heal, allowing clinicians the opportunity to develop tailored therapies, design prevention programs, and target specific surgical interventions in the view of a new and alternative concept of treatment based on pharmacogenomics.
Author contributions
References
- . Chronic leg ulcers (the impact of venous disease) . J Vasc Surg . 1999;29:752–755
- . Venous ulcer (epidemiology, physiopathology, diagnosis and treatment) . Int J Dermatol . 2005;44:449–456
- . A sociodemographic, clinical study of patients with venous ulcer . Int J Dermatol . 2005;44:989–992
- ‘Real’ epidemiology of varicose veins and chronic venous diseases (the San Valentino Vascular Screening Project) . Angiology . 2002;53:119–130
- . Leg ulcers (economic aspects) . Phlebology . 2000;15:110–114
- . The effect of medical elastic compression stockings with different slope values on edema. Measurements underneath three different types of stockings . Dermatol Surg . 2000;26:244–247
- . Venous ulceration (a cross-over study from nonoperative to operative treatment) . J Vasc Surg . 1996;24:788–792
- Surgical correction of isolated superficial venous reflux reduces long-term recurrence rate in chronic venous leg ulcers . Eur J Vasc Endovasc Surg . 2000;20:363–368
- Comparison of surgery and compression with compression alone in chronic venous ulceration (ESCHAR study) (randomised controlled trial) . Lancet . 2004;363:1854–1859
- Systematic review of outcomes after surgical management of venous disease incorporating subfascial endoscopic perforator surgery . J Vasc Surg . 2004;39:583–589
- Minimally invasive surgical management of primary venous ulcers vs. compression treatment (a randomized clinical trial) . Eur J Vasc Endovasc Surg . 2003;25:313–318
- . Risk factors for delayed healing and recurrence of chronic venous leg ulcers—an analysis of 1324 legs . Eur J Vasc Endovasc Surg . 2005;29:74–77
- . Risk factors associated with the failure of a venous ulcer to heal . Arch Dermatol . 1999;135:920–926
- . Hemochromatosis C282Y gene mutation increases the risk of venous leg ulceration . J Vasc Surg . 2005;42:309–314
- The overlapping of local iron overload and HFE mutation in venous leg ulcer pathogenesis . Free Radic Biol Med . 2006;40:1869–1873
- Factor XIII V34L polymorphism modulates the risk of chronic venous leg ulcer progression and extension . Wound Repair Regen . 2004;12:512–517
- . Penetrance of 845G →A (C282Y) HFE hereditary haemochromatosis mutation in the USA . Lancet . 2002;359:211–218
- Impaired wound healing in factor XIII deficient mice . Thromb Haemost . 2005;94:432–437
- . Fibrin stabilization (factor XIII), fibrin structure and thrombosis . Pathophysiol Haemost Thromb . 2004;33:430–437 2003-
- Saphenous vein sparing surgery (principles, techniques and results) . J Cardiovasc Surg . 1998;39:151–162
- . Reflux elimination without any ablation or disconnection of the saphenous vein. A haemodynamic model for venous surgery . Eur J Vasc Endovasc Surg . 2001;21:361–369
- . Investigation of chronic venous insufficiency (a consensus statement (France, March 5-9, 1997)) . Circulation . 2000;102:126–163
- Revision of the CEAP classification for chronic venous disorders (consensus statement) . J Vasc Surg . 2004;40:1248–1252
- A common mutation in the gene for coagulation factor XIII-A (Val34Leu) (a risk factor for primary intracerebral hemorrhage is protective against atherothrombotic diseases) . Am J Hematol . 2001;67:183–188
- . Prevalence of three common polymorphisms in the A-subunit gene of factor XIII in patients with coronary artery disease . Thromb Haemost . 1999;81:511–515
- . Evidence that the Cys282Tyr mutation of the HFE gene originated from a population in Southern Scandinavia and spread with the Vikings . Clin Genet . 2003;64:36–47
- The dinucleotide (CA) repeat polymorphism of estrogen receptor beta but not the dinucleotide (TA) repeat polymorphism of estrogen receptor alpha is associated with venous ulceration . J Steroid Biochem Mol Biol . 2005;97:266–270
- Single nucleotide polymorphisms of the fibroblast growth factor receptor 2 gene in patients with chronic venous insufficiency with leg ulcer . J Invest Dermatol . 2005;124:1085–1088
- . Tumor necrosis factor-alpha gene polymorphism associated with increased susceptibility to venous leg ulceration . J Invest Dermatol . 2006;126:921–925
- Factor XIII contrasts the effects of metallo-proteinases in human dermal fibroblast cultured cells . Vasc Endovascular Surg . 2004;38:431–438
- Serum iron and matrix metalloproteinase-9 variations in limbs affected by chronic venous disease and venous leg ulcers . Dermatol Surg . 2005;31:644–649
- . Factor XIII (FXIII) and angiogenesis . J Thromb Haemost . 2006;4:19–25
- . Molecular mechanisms underlying the proangiogenic effect of factor XIII . Arterioscler Thromb Vasc Biol . 2005;25:526–532
- . Affects of F XIII in wound-healing—Fibrin stability in tissues and cross linking of angiogenesis modulator, osteonectin to fibrin . Rinsho Byori . 1997;(Suppl 104):50
- . Iron release from human monocytes after erythrophagocytosis in vitro (an investigation in normal subjects and hereditary hemochromatosis patients) . Blood . 1998;92:2511–2519
Competition of interest: none.This study was supported in part by the Italian MIUR funds and by a grant from Fondazione Cassa di Risparmio di Ferrara, and Fondazione Cassa di Risparmio di Cento, Italy.
PII: S0741-5214(06)00917-7
doi:10.1016/j.jvs.2006.05.011
© 2006 The Society for Vascular Surgery. Published by Elsevier Inc. All rights reserved.
