Histological modification in TRAM flap in rats treated with pentoxifylline

Benefits of pentoxifylline for skin flap tissue repair in rats

Purpose

To assess the action of pentoxifylline, administered by subcutaneous route, on skin flap tissue repair in rats, and to verify the histological aspects and biomarkers.

Methods

Thirty-two male Wistar rats were divided into four groups: control (CT) and treated with pentoxifylline (P1, P3 and P5). Modified McFarlane technique flap was used. Ten days later, the animals were euthanized and the areas of viable and necrotic tissue were evaluated. Hematoxylin/eosin staining was used to assess the morphometric characteristics of the number of vessels and epithelial thickness. Picrosirius red was used to assess collagen density. VEGF and TGF-?1 levels on the skin flap and serum of the animals were measured by the ELISA method.

Results

The macroscopic evaluation of the skin flap dimensions showed reduced necrotic tissue in the pentoxifylline (p < 0.05) treated groups. There was an increase in angiogenesis and reepithelization, demonstrated by analyses with an increased number of vessels (p < 0.05), VEGF and epithelial thickness. Fibrogenic effect showed decreased collagen density and TGF-β1 in the skin flap and serum.

Conclusion

The benefits of pentoxifylline administered by subcutaneous route, at dose 100 mg/kg, which was effective to improve the survival of skin flap by acting on tissue repair components, stimulating angiogenesis and reepithelization, in addition to reducing fibrogenesis

Outcomes of a Treatment Protocol for Compromised Nasal Skin in Primary and Revision Open Rhinoplasty

Importance: This is the first study to review the incidence of nasal skin compromise after open rhinoplasty surgery and outcomes of treatment. Objectives: To determine whether risk of skin compromise after open rhinoplasty surgery can be predicted and whether our treatment protocol led to acceptable outcomes. Design, Setting, and Participants: This is a retrospective chart review of the senior author's private patients. In total, 384 rhinoplasty cases were reviewed and all cases with signs of vascular compromise requiring treatment were analyzed. Main Outcomes and Measures: Descriptive statistics were used to evaluate characteristics of patients who developed intra- and postoperative skin compromise, and unpaired two-tailed t-test was used to compare the characteristics of patients with and without compromised nasal skin when possible. Overall satisfaction results and complications in the skin compromise group were reported. Results: A total of 384 open rhinoplasties were performed by the senior author between October 1, 2015, and December 31, 2018. Of them, 109 were primary rhinoplasties and 275 were revision rhinoplasties. Of the 384 rhinoplasties, 27 (7%) had skin compromise leading to unplanned postoperative treatment. Two of the patients in the skin compromise group underwent primary surgeries (7.4%) and 25 underwent revision procedures (92.6%). Advanced age (p < 0.0001), prior or current history of smoking (p = 0.027), and greater number of prior rhinoplasty surgeries (p = 0.0002) were significantly correlated with risk of skin compromise. The average time to last follow-up in the skin compromise group was 392 days (range 15-1057 days). At their last follow-up, 12 patients had complete resolution of all signs of nasal skin compromise with no further treatment required (44.4%). The revision rate for patients experiencing skin compromise was 22.2%. One patient underwent revision surgery directly related to a complication of skin compromise and one is considering revision directly related to skin breakdown. Conclusions and Relevance: The rate of skin compromise after open rhinoplasty is low. Older patients and patients with more prior rhinoplasty surgeries may be at increased risk. Prompt treatment of compromised nasal blood supply after rhinoplasty surgery can salvage skin in most patients.

Viability of randomized skin flaps-an experimental study in rats

BACKGROUND

Randomized skin flaps are extensively used in plastic surgery, but the possibility of necrosis has challenged their use. Several studies have been conducted aiming to find ways to reduce the occurrence of necrosis. We evaluated the effects of pentoxifylline (PTX) and hyaluronidase (HLD), each alone or combined, on randomized rat skin flaps.

MATERIALS AND METHODS

Fifty male Wistar rats were divided into five groups of 10 animals each: control I, control II, PTX, HLD, PTX-HLD. Substances were administered from the first to the 14th postoperative day. The necrotic area was measured on the seventh and 14th postoperative day; the animals were killed on the 14th day, when samples were collected for histologic and immunohistochemical examination.

RESULTS

On the seventh day, percentage of the necrotic area was significantly reduced in PTX, HLD, and PTX-HLD animals compared with control groups. On 14th day, percentage of the necrotic area in PTX, HDL, and PTX-HLD groups was also significantly reduced compared with control groups. PTX and PTX-HLD showed a significant reduction in dermis cellularity, V_V of macrophages, and myofibroblasts compared with control groups; PTX showed a significant enhancement of L_V of blood vessels compared with all other groups.

CONCLUSIONS

The use of each substance alone or combined increased flap viability compared with control groups. On the seventh day, PTX exhibited lower viability than HLD, whereas on the 14th day there was no difference between treated groups. PTX alone enhanced the L_V of blood vessels, whereas PTX-HLD did not. However, PTX-HLD was more effective in decreasing the dermis cellularity and macrophage V_V than HLD alone.