An experimental study of the effect of pre-operative administration of cilostazol on random skin flap survival in rats: double blinded randomized controlled trial

Non-operative adjuncts for the prevention of mastectomy skin flap necrosis: a systematic review and meta-analysis

BACKGROUND

Native skin flap necrosis is a potentially devastating complication following skin-sparing or nipple-sparing mastectomy with a reported incidence of as high as 30%. Treatment depends on the depth and extent of tissue necrosis and can range from dressings to surgical debridement and further reconstruction. This can have implications on patient physical and psychological wellbeing as well as cost of treatment. This study aims to identify and appraise cost-effective non-surgical adjuncts for the prevention of native skin flap necrosis.

METHODS

A systematic review was performed using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement and structured around existing recommended guidelines. A search of MEDLINE, EMBASE, Cumulative Index to Nursing and Allied Health Literature and ClinicalTrials.gov was performed with the medical subject headings 'mastectomy' and 'flap necrosis'. After exclusion, 12 articles were selected for review and analysed.

RESULTS

A total of 8439 mastectomies were performed on 7895 patients. Preventative non-surgical adjuncts that demonstrated statistically significant reduction in mastectomy flap necrosis included topical nitroglycerin ointment (P = 0.000), closed-Incision negative pressure wound therapy (P = 0.000), topical dimethylsulfoxide ointment (P = 0.03), oral cilostazol (P = 0.032), and local heat pre-conditioning (P = 0.047).

CONCLUSIONS

This study identifies multiple adjuncts that may aid in preventing mastectomy skin flap necrosis, especially in high-risk patients. Further studies could aim to define standardized protocols and compare the various adjuncts in different circumstances.

Standardization of the Rat Dorsal Random Pattern (McFarlane) Flap Model and Evaluation of the Pharmacological Agents Aiming to Salvage Partial Flap Necrosis: A Systematic Review and a Meta-analysis

INTRODUCTION

Partial flap necrosis is a common complication after surgery. McFarlane flap model has been used for assessment of various agents' effects on random flap survival. The aim of this study was to review the methodology of studies using this flap model and reveal the most successful agents.

MATERIALS AND METHODS

PubMed, Scopus, and Web of Science databases were screened for words "McFarlane flap," "flap survival," and ("flap" and "rat") by using time limits between 1965 and 2019. A total of 71 original articles were reviewed. Dimensions and base (cranial/caudal) of the flap, treatment protocol, follow-up period, and survival rates were extracted. Modified survival rates were calculated. Coefficients of variation of cranial/caudally based control group flaps and most commonly used flap models were calculated to assess interstudy variability.

RESULTS

A total of 165 different treatment regimens were studied. One-hundred twelve regimens (67.9%) were found to increase flap survival. Most common flap dimensions were 9 cm × 3 cm, followed by 10 cm × 3 cm, 8 cm × 2 cm and 6 cm × 2 cm. Studies using caudally based flaps showed less interstudy variability, but survival rates were similar. Pentoxifylline, sildenafil, chlorpromazine, phenoxybenzamine, and phentolamine were reported to be successful in multiple studies.

CONCLUSIONS

There are numerous agents found to be effective for treatment of partial flap necrosis, but further clinical research is needed. To overcome standardization problems, use of commonly used flap dimensions with a caudal base and interpretation of results after 7 days of follow-up seems appropriate.

Effect of dipyridamole on random pattern skin flap viability in rats

Ischemic necrosis has been most dreaded complication of flap reconstruction. Therefore, researchers have tried to improvise modalities to prevent or treat it since the onset of flap surgery. So far these researches have failed to identify a pharmacological therapy equally effective as surgical delay in augmenting skin flap viability. In the path of search for this substance, dipyridamole attracted our attention as an antiaggregant agent. Put together with pathophysiological mechanisms underlying ischemic flap necrosis, we concluded dipyridamole might have beneficial effect on survival of skin flaps. In this research random pattern dorsal rat skin flap model of McFarlane is used. Subjects are separated in a randomized fashion between two groups. Experiment group is given dipyridamole with a dose of 20 mg/kg twice daily. Control group is given same amount of saline. At seventh day viability of skin flaps is assessed and compared between groups. Also on 7th day, pathologic specimens are obtained and evaluated histopathologically in terms of neutrophil and lymphocyte infiltration, edema and fibrosis. Necrosis percentage in experiment group is found to be significantly lower than that of control group (p < 0.01*). Neutrophil infiltration and edema found to be significantly lower in dipyridamole group (p < 0.05*). No significant difference is observed in lymphocyte infiltration and fibrosis. Dipyridamole is shown in this research to be effective in augmenting viability of random pattern skin flaps in rats. Nevertheless, more extensive researches are needed to fully determine its precise mechanism, side effects and appropriate doses.

Preemptive treatment with photobiomodulation therapy in skin flap viability

Skin Flap is used in reconstructive plastic surgery. However, complications such as ischemia followed by local necrosis may occur, requiring a new surgical procedure. It is well known that photobiomodulation therapy (PBMT) is an effective technique for improving microcirculation and neoangiogenesis, which contributes positively to the blood supply in the pre and post surgical period. Thus, the objective of the present study was to investigate the effects of preemptive treatment with laser PBMT with different energies on the viability in skin flaps in rats. Sixty-three Wistar rats, male, were randomized into five groups: Control Group (CG) (n = 15): PBMT simulation; Preemptive group 1.1 J laser (GP1) (n = 15): preemptive laser PBMT with 1.1 J of energy per point; Preemptive group 4 J laser (GP4) (n = 15): preemptive PBMT with 4 J of energy per point; Laser group 11 J (G1) (n = 9): PBMT immediately after surgery with 1.1 J of energy per point; Laser group 4 J (G4) (n = 9): TFMB immediately after surgery with 4 J of energy per point. The CG, GP1 and GP4 groups started treatment 72 h prior to surgery and were subdivided into two experimental periods, one of them on the day of the flap and the other along with the other groups on the seventh postoperative day. Three days after the randomization, the animals underwent random skin flap surgery. PBMT was performed with a 660 nm laser at three points. In the first experimental period, a greater number of vessels were found, as well as mast cells in GP1 compared to the CG and greater expression of fibroblast growth factor and vascular endothelial growth factor in the GP1 and GP4 groups compared to the CG. In the second experimental period, GP1 presented a lower percentage of necrotic tissue, a higher number of vessels and a percentage of cells labeled with both VEGF and hypoxia indicible factor alpha (HIF-1α) compared to the CG, FGF in GP1, GP4 and G4 when compared to the CG. Thus, it was concluded that preemptive treatment with PBMT with the application of 1.1 J of energy per point is effective in improving the viability of the skin flap.

Effect of local application of transcutaneous carbon dioxide on survival of random-pattern skin flaps

INTRODUCTION

Skin flap procedures are widely used to reconstruct skin and soft tissue defects. Skin flap necrosis is a serious postoperative complication. Many researchers have introduced pharmacological agents to improve flap ischemia in experimental studies. However, outcomes of these studies remain controversial. We previously demonstrated that transcutaneous CO₂ application improves hypoxia in fracture repair. In this study, we hypothesized that improving hypoxia by transcutaneous CO₂ application can improve the blood flow in skin flaps and increase angiogenesis. We investigated whether transcutaneous CO₂ application can increase the survival of random-pattern skin flaps.

MATERIALS AND METHODS

Six-week-old male Sprague-Dawley rats were divided into two equal groups: the control group (n = 6) and CO₂ group (n = 6). A random-pattern skin flap was constructed in these rats. Topical CO₂ was applied using a hydrogel every day for 5 days in the CO₂ group. The flap survival area was measured on postoperative days 1, 3, and 5. The vessel density and expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and hypoxia-inducible factor-1α (HIF-1α) were evaluated on postoperative day 5.

RESULTS

A statistically significant difference was found in the percentage of the flap survival area between the two groups on postoperative days 3 and 5 (p < 0.05). Furthermore, the expression of VEGF and bFGF was significantly higher and that of HIF-1α was significantly lower in the CO₂ than in the control group (p < 0.05).

CONCLUSIONS

Transcutaneous CO₂ application can improve the blood flow in skin flaps and increase angiogenesis, thus increasing the survival of random-pattern skin flaps.

Effect of cilostazol in experimental model of degloving injuries in rat limbs

PURPOSE

To evaluate the effect of the cilostazol on the evolution of partially avulsed flaps, using experimental model of cutaneous degloving in rat limbs.

METHODS

A controlled and randomized experimental study was carried out in which the blood flow and the percentage of flap necrosis were evaluated. We compared the study group, which received cilostazol, and the control group, which received enteral saline solution in the postoperative period. The blood flow in the flap was evaluated through Laser Doppler flowmetry, and a planimetry using the IMAGE J® software was employed for the calculation of the area of necrosis.

RESULTS

Enteral administration of cilostazol was associated with a higher mean blood flow in all regions of the flap, with a statistically significant difference in the proximal and middle regions (p<0.001) and a lower percentage of necrotic area in the flap (p<0.001).

CONCLUSION

Postoperative enteral administration of cilostazol increased blood flow and decreased the total area of necrosis of avulsed cutaneous flaps of rat limbs.

Effects of açaí and cilostazol on skin microcirculation and viability of TRAM flaps in hamsters

BACKGROUND

Tissue necrosis caused by insufficient perfusion is a major complication in flap transfer. This study evaluated whether treatment with cilostazol or hydroalcoholic extract of seeds of Euterpe oleracea Mart. (açaí) protects the transverse rectus abdominis myocutaneous (TRAM) flap against ischemic damage in hamsters.

MATERIALS AND METHODS

Fifty-four hamsters were divided into three oral treatment groups: placebo, açaí, or cilostazol. Caudally based, unipedicled TRAM flaps were raised, sutured back, classified into four vascular zones (I-IV), and evaluated for tissue viability, capillary blood flow (CBF), perfused vessel density (PVD), and microvascular flow index (MFI) by orthogonal polarization spectral imaging at three time points: immediately postoperatively (IPO), 24 h postoperatively (24hPO), and 7 d postoperatively (7POD).

RESULTS

Comparing to placebo, açaí increased PVD at IPO and açaí and cilostazol increased CBF and PVD at 24hPO in zone I; cilostazol increased CBF, PVD, and MFI at IPO, and CBF at 24hPO in zone II; açaí and cilostazol increased CBF at all time points and PVD and MFI at IPO and 24hPO in zone III; cilostazol increased CBF at IPO and 7POD, açaí increased CBF at 7POD, and both increased PVD and MFI at all time points in zone IV; and açaí and cilostazol increased the percentage of viable area in zones III and IV.

CONCLUSIONS

Açaí and cilostazol treatments had a protective effect against ischemic damage to TRAM flaps in hamsters, improving microvascular blood flow and increasing the survival of flap zones contralateral to the vascular pedicle (zones III and IV).

The protective effect of cilostazol on transverse rectus abdominis myocutaneous flap in rats

OBJECTIVE

Transverse Rectus Abdominis Myocutaneous (TRAM) flap is commonly used in breast reconstruction. The aim of this study is to demonstrate the effects of cilostazol on TRAM flap viability in a rat TRAM model.

METHODS

Twenty-four Wistar rats were used. They were divided into four groups. Rats in Group 1 were applied TRAM flap. In Group 2, cilostazol 30 mg/kg was administered to rats via oral gavage 3 hours before the flap surgery. After the flap surgery, cilostazol 30 mg/kg was administered via oral gavage twice a day for 7 days. In Group 3 before the flap surgery, cilostazol 30 mg/kg was administered via oral gavage twice a day for 7 days, and treatment continued for 7 more days after the flap surgery. In Group 4 before the flap surgery, cilostazol 30 mg/kg was administered via oral gavage twice a day for 7 days and treatment was discontinued after the flap surgery.

RESULT

The mean necrosis rate in Group 1 was 41.69%, in Group 2 it was 27.0%, in Group 3 it was 6.66%, and in Group 4 it was 11.2%. The necrosis rate in Group 1 was found to be statistically significantly higher than other groups (p < .01), the necrosis rate in Group 2 was found to be statistically significant higher than Groups 3 and 4 (p < .01), and the necrosis rate in Group 4 was found to be statistically significant higher than Group 3 (p < .01).

CONCLUSION

Cilostazol treatment seemed to increase the viability of TRAM flap, especially when administered as adjuvant therapy.