Modified protective rat vest

Edemas of the face and lymphoscintigraphic examination

Facial edemas not secondary to surgery and/or radiotherapy for head and neck cancer are relatively uncommon. Our aim is to report a retrospective analysis of the lymphoscintigraphic and SPECT-CT investigations obtained in patients with such facial edema. Retrospective review of exams (planar imagings in all and with SPECT-CT in 5) obtained after the subcutaneous injection of 99mTc HSA Nanosized colloids between the eyebrows in five men and seven women. Four main lymphatic pathways were identified on sequential planar imagings: para-nasal left and right and supra- ocular left and right. For eleven patients, the absence of visualization of lymphatic drainage and/or their delayed appearance correlated well with the localisation of the edematous areas. In two patients with post-traumatic and post- surgical edemas, SPECT-CT showed one deep left sided cervical lymph node (LN) in front of the first cervical vertebra. This lymphoscintigraphic approach represents a simple and valuable way to assess the lymphatic drainage pathways of the face and to establish the diagnosis of facial lymphedema.

Venous component in scar penetrating neovascularisation

BACKGROUND

The impact of old scar tissue on the venous anatomy of a flap's pedicle is an important question in reconstructive surgery. This study tried to investigate the venous component in scar penetrating neovascularisation.

METHODS

Fifty Sprague-Dawley rats were used in this experimental study. Two experimental groups were designed. In the first group, incisions were performed over the epigastric flap pedicles. In the second group, 1 cm wide segments were excised over the pedicles. Ten weeks after the initial operations, angiographies and histological examinations were performed. A control group was used to demonstrate the normal arterial and venous anatomy of the pedicle.

RESULTS

Arterial angiographies revealed that axial pattern arteries were visible in the incision group as opposed to the excision group. Although venous angiographies showed that there were more venous capillary formations in the incision group, none of the experimental groups had regenerated a vein with an axial pattern. Histological examinations revealed that venous vessel formations were significantly less in the distal samples of the experimental groups when compared to the control group (p < 0.05).

CONCLUSIONS

In this study, it has been observed that arterial pedicles do regenerate over old incision scars as opposed to veins. In the excision scars neither arterial or venous restoration of the axial pedicle was possible. In these cases, only a random type of limited circulation was restored.

Etanercept protects myocutaneous flaps from ischaemia reperfusion injury: An experimental study in a rat tram flap model

Background Being an inevitable component of free tissue transfer, ischemia-reperfusion injury tends to contribute to flap failure. TNF-α is an important proinflammatory cytokine and a prominent mediator of the ischemia-reperfusion injury. Etanercept, a soluble TNF-α binding protein, has shown anti-inflammatory and anti-apoptotic effects in animal models of renal and myocardial ischemia-reperfusion injury. We have designed an experimental study to investigate the effect of etanercept on myocutaneous ischemia-reperfusion injury on transverse rectus abdominis myocutaneous flap model in rats. Methods Twenty-four male Sprague-Dawley rats were divided into 3 groups: In group 1 (sham), the TRAM flap was raised and sutured back without further intervention. In group 2 (control), the flap was raised and the ischemia-reperfusion protocol was followed. In group 3, etanercept (10 mg/kg, i.v.) was administered 10 minutes before reperfusion. At the end of the reperfusion period, biochemical and histolopathological evaluations were performed on serum and tissue samples. Results In the etanercept group the IMA and 8-OHdG levels (p = 0.005 and p = 0.004, respectively) were found significantly lower, and the GSH and SOD levels (p = 0.01 and p < 0.001, respectively) significantly higher in comparison to the control group. The histopathological analysis has revealed a lower degree of hyalinization, degenerated muscle fibers and nuclear change in the etanercept group compared to the control group. Conclusion The results of our experimental study indicate that etanercept offers protection against ischemia-reperfusion injury in skeletal muscle tissue, enhancing the TRAM flap viability. The ability of etanercept to induce ischemic tolerance suggests that it may be applicable in free-flap surgery.

Evaluation of scar penetrating neovascularisation in a rat epigastric flap model

AIM

The aim of this study is to investigate neovascularisation patterns in the presence of scar tissue and to compare the venous vs arterial components of the scar penetrating neovascularisation.

METHODS

Forty male Spraque-Dawley Rats, which were divided into four groups, were used for this study. At the beginning of the study a vertical midline abdominal incision was made to all animals. Six weeks after the incisions were made, epigastric flaps based on inferior epigastric vessels were raised. In the first group both left and right epigastric artery and veins were protected. In the second group only the right epigastric artery and vein was protected. In the third group, besides the right epigastric artery and vein, only the left epigastric artery was kept intact. In the fourth group, besides the right epigastric artery and vein, only the left epigastric vein was kept intact.

RESULTS

The percentages of necrotic areas on the flaps were statistically evaluated. The percentages of the necrotic areas on the left side of the flaps were significantly higher in the second group (p = 0.0305). Total flap area necrosis was also significantly higher in the second group (p = 0.026). In each group, vessel formations were identified which were extending through the midline scar tissue in the angiographic evaluations.

CONCLUSIONS

These results suggest that scar penetrating neovascularisation on an epigastric flap with one sided pedicle, which is supported by a vein or an artery on the contralateral side, can be enough to facilitate the flap circulation.

Innervation of skin grafts over free muscle flaps

Skin grafts regain their sensory innervation from the graft bed by the regeneration of nerve endings. Although some clinical studies report sensory recovery in skin grafts implanted on free muscle flaps, the mechanism of recovery is obscure. The purpose of this study was to investigate nerve regeneration in experimental skin grafts on free muscle flaps to elucidate this phenomenon. Thirty-eight male Sprague-Dawley rats, weighing 450-550 g were used in the study. The rat gracilis muscle flap was the free flap model transferred from one groin to the other using microvascular anastomoses. Full-thickness skin grafts harvested from the abdomen were used to cover the free muscle flaps after transfer. Four study groups were formed: Group I (n = 10): Free muscle flaps were transferred without any nerve anastomosis; Group II (n = 10): Free flaps transferred with the anastomosis of the muscle's motor nerve to a sensory nerve at the recipient site; Group III (n = 10): Free flaps transferred with the anastomosis of the muscle's motor nerve to a motor nerve at the recipient site; Group IV (n = 8): Skin grafts were placed directly on the fascia layer over the medial hindlimb muscles and served as controls. The specimens were harvested for histologic examination after 12 weeks. Histologic examination was performed to visualise regenerating nerve endings using H&E, S100, Luxol Fast Blue and tyrosine hydroxylase staining. The specimens were categorically scored according to the staining pattern of neural structures around pilosebaceous units and statistical comparisons were performed by using paired t-test. Skin grafts in both Group II and Group III markedly received tyrosine hydroxylase at the base of their pilosebaceous units in many of the specimens and functional nerve twigs could also be traced from the muscle layer to the overlying skin graft. In contrast, the skin grafts in Group I did not show any nerve function in the central parts. The overall staining scores of Groups II, III and IV were significantly higher than Group I (P < 0.05; P < 0.001; P < 0.05, respectively). There was no statistically significant difference between other groups. No myelinated nerve fibres could be detected in any of the skin grafts with Luxol Fast Blue technique. It was concluded in the present study that skin grafts over reinnervated free muscle flaps can develop significantly better innervation than skin grafts over non-innervated muscle flaps. However, the activity in skin appendages indicating nerve regeneration may only imply a gross sensation and in the absence of any myelinated nerve fibres transmission of finer sensation cannot be expected in any of the study groups.