Distally based perforator flaps for reconstruction of post-traumatic defects of the lower leg and foot. A review of the anatomy and clinical outcomes.

STUDY AIMS: To report the surgical anatomy of the perforator arteries at the lower leg, analyse clinical outcomes in previous studies, and forward methodological recommendations for future studies of post-traumatic perforator flap reconstructions. METHODS: A study sample of 640 human patients drawn from 24 clinical reports was included for review. The sample comprised of four subsets: sural flap reconstructions (n=257), saphenous flaps (n=122), supramalleolar flaps (n=92), and propeller flaps (n=169). RESULTS: Statistical analysis of samples from anatomical studies documents significant differences in the perforator distribution from the tibial and peroneal artery; peroneal perforator arteries are randomly organised whereas tibial artery perforators are clustered at three definite levels. The failure rates in clinical studies ranged from 0% to 6%, being lowest for supramalleolar flap reconstructions and highest for saphenous flaps; however, differences between the four subsets were not statistically significant at the 95% confidence level. Due to methodological flaws, outcome comparisons in the actual study sample should be interpreted cautiously; in most clinical studies both risk variables and outcome indicators are poorly defined. The outcome of Dynamic Infrared Thermography imaging of post-transposition changes of flap perfusion is reported. SUMMARY: Fasciocutaneous perforator flaps seem to have high survival rates and represent a feasible approach to post-traumatic reconstructions, especially in low-resource settings. A template for data gathering is recommended for higher accuracy in future comparative studies, and for scientific analysis of success and risk factors. New imaging techniques indicate a promising potential of micro-circular angiogenesis during the first two weeks after flap transpose.

[Saphenous perforator flap]. / Der Saphenusperforatorlappen.

OBJECTIVE: Replacement of full thickness soft tissue defects in the lower leg and ankle, appropriate to the defect and following the course of blood vessels feeding the skin of a distally hinged fasciocutaneous flap most reliably based on the individual anatomy of distal perforators of the posterior tibial artery. INDICATIONS: Full thickness soft tissue defects, up to 12 cm in length and up to 8 cm in width. Sufficient vascularization of the foot required, in osteomyelitis, and when joints, fractures, implants and tendons are exposed and when a split skin graft, a local flap, a suralis perforator flap or a free flap is not indicated. CONTRAINDICATIONS: For patients, in whom a 1-2 h operation is not possible; necessity of angioplasty; decollement or scars around the distal perforators of the posterior tibial artery; local infection or necrosis of soft tissues and/or bone, which cannot be totally excised. SURGICAL TECHNIQUE: Radical debridement; flap dissection without tourniquet; microdissection; design of the flap on the skin: pivot point ~ 10 cm (6-14 cm) proximal of the tip of the medial malleolus; base ~ 5 cm in width, between the course of the saphenous nerve and of the great saphenous vein and the Achilles tendon; adipofascial pedicle up to 15 cm in length sited over the septum between soleus and flexor digitorum muscles, following the course of the saphenous nerve, with a central skin stripe, which expands into a proximal skin island; skin island is outlined similar to the defect, but larger by 1 to 2 cm, surrounded by an adipofascial border: adjustment of the planning as well as of the elevation of these flaps according to the individual position and the caliber of perforators requires in each case the search for a perforator at the estimated pivot point. Delay of transposition, if the division of more than one perforator proximal to the pivot point obviously diminishes circulation. No "tunnelling "of the pedicle; defects of skin due to the elevation of the flap are replaced by split and meshed skin grafts or temporary by "artificial skin". A gap in the bandage over the skin island allows for observation. POSTOPERATIVE MANAGEMENT: Protocol of controls of vascularization: color and time for revascularization; antibiotic treatment according to bacteriological testing. In case of edema or discoloration of the flap: immediate removal of sutures, administration of leeches, operative revision. Split skin graft 1 week after flap transposition, if the skin had been temporary substituted. RESULTS: Retrospective uncontrolled study with over 70 saphenous perforator flaps from 1995-2011. Full soft tissue defects 62 times with osteomyelitis, 3 times with endoprothesis, 3 times with fractures, 2 times with exposed tendons. From 1995-2006, 44/50 (88 %) flaps healed completely or at least to 3/4 without the necessity of further flaps; from 2007-2011, 13/20 (65 %) flaps healed completely and 6/20 (30 %) flaps healed at least to 3/4 without the necessity of further flaps, loss of one flap (5 %).

Sural perforator flap for reconstructive surgery in the lower leg and the foot: a clinical study of 86 patients with post-traumatic osteomyelitis.

BACKGROUND: The treatment of post-traumatic osteomyelitis of the lower leg and the foot remains a challenge in reconstructive surgery. MATERIAL AND METHODS: Eighty-six patients with lower leg post-injury chronic osteomyelitis were included in a retrospective, non-controlled clinical study conducted from 1995 to 2006. All study patients were managed by distally based sural neuro-fascio-cutaneous perforator flap. An endpoint survey was conducted after flap surgery and had a mean follow-up period of 5.5 years, wherein the response rate was 48%. RESULTS: Seven patients had a short-term flap failure (8%; 95% CI 3-16%). An additional eight patients (7%) had flap necrosis of less than one-fourth of the flap that healed without surgical revision. Based on the endpoint data, the long-term success rate was 87% (95%, CI 72-96%). Local and/or systemic physiological compromise was a risk factor for flap failure. Other assumed risk factors had no statistically significant impact on short- or long-term results. CONCLUSION: Sural perforator flap is a robust flap with low failure rate, even in high-risk patients. The success rate compares favourably with results of free flap transfers in the management of post-traumatic osteomyelitis. The flap has a wide range, and the surgical technique is rather simple. The sural flap is a feasible option for post-traumatic reconstructions of osteomyelitis, especially in low-resource settings.

Studies on supratentorial subdural bleeding using a porcine model.

A porcine model for an acute lethal arterial subdural bleeding in man is presented. Blood from the abdominal aorta was led via an electronic drop recorder into a collapsed intracranial subdural rubber balloon. Systemic arterial pressure (SAP), two intracranial pressures and 6 other vital parameters were monitored continuously in spontaneously breathing (n = 4) and mechanically ventilated (n = 4) pigs. In both animal groups bleeding caused an immediate rise in intracranial pressures (ICP) with transtentorial pressure gradients developing. As a result the cerebral perfusion pressures (CPP) decreased progressively, leading to an isoelectric EEG. In spontaneously breathing animals, the pressure changes resulted in apnoea within 2-4 minutes, irregularities in heart rhythm and in a marked rise in SAP (the Cushing reaction). A final collapse of all pressures occurred after 222 +/- 68 sec at a mean bleeding volume of 10.3 +/- 1.9 ml. In contrast, in mechanically ventilated animals, the course of bleeding was less dramatic. No change in cardiac rhythm or rise in SAP appeared despite a larger mean bleeding volume (12.0 +/- 1.6 ml). Instead, SAP slowly fell, reaching a level of approximately 40 mm Hg within 1 hour, while CPP concomitantly decreased from 120 mm Hg to 15 mm Hg. The findings in this and in a parallel study are explained in terms of the intracranial volume tolerance concept (Zwetnow et al. 1986). The beneficial effect of assisted ventilation on the course of subdural bleeding is multifactorial, involving both metabolic and mechanical mechanisms.