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Wounds were washed daily both the LAD group         Statistical analysis
          and the conventional group prior to dressing with   Statistical analysis was performed using the student’s t‑test
          5% povidone‑iodine solution. Of these 140  patients,   for comparisons between groups (SPSS, 15th version (233
          56 participants  (22 in the LAD group and 34 in the   South Wacker Drive, 11th Floor, Chicago)). The data were
          conventional dressing group) were lost to follow‑up. Of   expressed as mean  ±  standard error  (SE).  P  < 0.05 was
          42  patients  in  the  LAD  group,  22  (52%)  were  women,   considered to be significant. When appropriate, statistical
          and 20  (48%) were men. In the conventional dressing   uncertainty was expressed with 95% confidence levels.
          group, 18  (42.8%) were women, and 24  (57.1%) were
          men.  Biopsies  were  taken  on  days  0  and  10  and  were   RESULTS
          analyzed  for  the  histopathologic  parameters  under
          study.                                              On day 0, both the LAD and conventional groups showed

          Randomization                                       necrotic  tissue  with  increased  inflammatory  infiltrates
          Patients were randomized by generating tables of random   [Figures 2A and 3A]. On day 10, the LAD group [Figure 2B]
          numbers through www.random.org. Numbers were        showed an increase in ECM deposition and angiogenesis
          assigned  to a treatment  group and sealed in opaque   with a decrease in  inflammatory infiltrate when
          envelopes containing labeled paper  with the treatment   compared to the conventional group [Figure  3B]. The
          and patient ID.                                     results of the histopathologic scoring are shown in
                                                              Table  2.  Histopathology  revealed  that  in  LAD  group
          Tissue preparation for histopathologic study        after 10 days of treatment, the scores of necrotic tissue
          Wound biopsies performed on days 0 and 10 were      (P  =  0.007) and inflammatory cell infiltrate (P  =  0.018)
          collected, fixed in 10%  formalin, dehydrated through   were significantly lower than those of the conventional
          an increasing alcohol  series  (50%, 70%, 90%, and 100%),   treatment group. The score of ECM deposits and number
          cleared in  xylene  and embedded  (Leica EG1150 H) in   of blood vessels on day 0 were not well‑defined in either
          paraffin wax (melting point 56°C). Serial sections of 5 µm   group,  but  on  day  10  ECM  deposits  (P  =  0.001)  and
          thickness were cut using  a microtome  (Leica RM2255)   number of blood vessel (P = 0.005) were significantly
          and were stained with hematoxylin‑eosin  (Sigma‑Aldrich,   higher in the LAD group than in the conventional group
          MO, USA). Each section was evaluated in  8 microscopic   [Table 2, Figure 4].
          fields  (×100)  under light microscopy  (Olympus PM20).
          Histopathology slides were graded using a modified   DISCUSSION
          0‑4 Ehrlich and Hunt numerical scale, and modified and
          internally validated in our laboratory on a scale of 1‑3,   Wound healing  is  a  complex and dynamic  process  which
          with 1 representing necrosis, 2 representing inflammatory   involves cell‑cell interactions and cell‑matrix interaction.
          cell infiltration (white blood cell and fibroblast count), and   The proliferative  phase of wound healing  is  marked by
          3 representing  ECM  deposition.  We  used  a 5‑point scale   angiogenesis,  collagen  deposition, granulation tissue
          to  evaluate  the  presence  of  necrosis  and inflammatory   formation, epithelialization,  and wound contraction
          cell infiltration  (0, no evidence; 1, occasional  evidence;   resulting in less scar tissue. [10]
          2, light scattering; 3, abundant evidence; 4, confluent cell)   A study by Nain  et  al.  showed a decrease in the
                                                                                    [11]
          as previously  described,  and used a 4‑point scale to   amount of necrotic tissue in chronic wounds treated with
                               [8]
          evaluate the presence of ECM deposition (0, no evidence;   NPWT. Histopathological  analysis showed significantly
          1, little ECM deposition; 2, moderate ECM deposition;   less  necrotic  tissue  in  the  LAD  group  compared  to  a
          3, confluent  ECM  deposition) as previously  described.    conventional  dressing  group  after  10  days  of  treatment
                                                          [8]
          In  determining  the  degree  of angiogenesis,  only mature   (mean ± SE, 11.5 ± 0.48 vs. 10.1 ± 0.30, P = 0.007). The
          vessels were counted and identified by the presence of   ECM is made up of collagen fibers and glycosaminoglycans,
          erythrocytes in their lumen.  The score was assigned by 2
                                 [9]
          investigators.  The code describing  the specific treatment
          received by the patient was broken after scoring had been
          completed by the investigators.


          Table 1: Patient demographics and baseline wound
          characterization
           Details              LAD group     Conventional
                                                 group
                                                               A                     B
           Number of patients      42              42
           Age, years (mean ± SD,  (38.3 ± 10.56, 12-60)  (35.3 ± 14.0, 17-65)   Figure 2: Histopathology of granulation  tissue  on days 0  and 10  in  the
                                                              limited access dressing (LAD) group. A: (a) LAD group  ‑ day 0  ‑ (arrow)
           range)                                             abundant inflammatory cells, (b) poorly developed matrix, (c) minimal blood
           Mean wound size (cm )  28 (range: 19-40)  26 (range: 18-39)  capillaries. (photographed with an Olympus PM20 photomicroscope ×20);
                          2
           Female (%)              52             42.8        B:  (a)  LAD  group  ‑  day  10  ‑  (arrow)  increased  number  of  fibroblast  cells,
           Male (%)                48             57.1        (b)  fewer  inflammatory  cells,  (c)  increased  proliferating  blood  capillaries,
                                                              (d) collagen bundles organized well between the cells (photographed with
           LAD: Limited access dressing, SD: Standard deviation  an Olympus PM20 photomicroscope ×20)

           274                                                           Plast Aesthet Res || Vol 2 || Issue 5 || Sep 15, 2015
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