Timpanoplastia secundaria contejido aerolar laxo y nutriciónsubdérmica / Secondary tympanoplasty with areolar tissue and subdermal nutrition

La timpanoplastia secundaria es un reto quirúrgico debido a que varios factores intervienen para obtener un resultado satisfactorio. Múltiples materiales han sido descritos para el cierre de las perforaciones timpánicas secundarias con tasas de éxito que oscilan en promedio del 93 por ciento. Los autores de este estudio describen una técnica quirúrgica que ha sido de gran utilidad en el Hospital Universitario del Valle, Cali, Colombia, para el cierre de perforaciones timpánicas secundarias con tejido areolar laxo. Este injerto posee una citoarquitectura ideal para integrarse al oído. Se reporta en esta serie una tasa de cierre de la perforación del 97 por ciento y una mejoría audiológica promedio de 21dB. Se considera que el mayor aporte vascular que se logra a través de la disección del ánulus posterior, colgajos meatales y timpánicos contribuyen de manera significativa a la viabilidad del injerto.

Secondary timpanoplasty is a surgical challenge since various factors contribute to obtain a satisfactory result. Multiples materials have been described for perforation closure in secondary timpanoplasty with a mean success rate around 93 percent. The authors describe a surgical technique that has proved to be of great help at the Hospital Universitario del Valle in Cali, Colombia with areolar tissue. The histological properties of areolar tissue makes it ideal for tympanic membrane repair. We report a closure rate of the 97 percent and a fair audiological results with a PTA less than 21 dB for the described series. The authors believe that a bigger blood supply that is achieved by posterior annulus dissection, meatal and timpanal flaps contribute significantly to the survival of the graft.

Role of Perivenous Areolar Tissue in the Viability of Island Flaps with an Exclusively Venous Pedicle

For the venous flap to survive, it apparently needs to be a flow-through of venous blood.1 Nevertheless, controversy remains, regarding the fact that an island flap based on a terminating venous pedicle is capable of maintaining viability.2-15 This study was designed to investigate the role of perivenous areolar tissue in the viability of island flaps with an exclusively venous pedicle in the rabbit ear model as described by Inada et al.16 Ten groups of flaps were studied: Group A-flaps based on a proximal venous pedicle; group B-flaps based on a distal venous pedicle; group C- nonvascularized grafts; each subgroup A1-, B1-flaps with perivenous areolar tissue; each subgroup A2-, B2-flap which was skeletonized pedicle; each subgroup A3-, B3-flap was same as A1-, B1-flap, which was sutured over a silastic sheet; each subgroup A4-, B4-flap with a skeletonized venous pedicle sutured over a silastic sheet; subgroup C1-control, placed directly on bed; subgroup C2-control which was sutured over a silastic sheet. Groups A3, A4, B3 and B4 had 20 flaps and the remaining groups had 10 flaps each. Flaps in group A1, A3, B3 had total survival. In groups A4, B4, C2, no flaps were survived. The survived flaps in groups A3 and B3 had tissue oxygen content values between those of arterial and venous levels. Histological examination of the pedicle of survived flaps in groups A3 and B3 showed small vascular channels present in the areolar tissue surrounding the venous pedicle. Static and dynamic computerized radioactive tracer experiments showed that the survived flaps in groups A3 and B3 were promptly perfused and drained through their pedicles. This study confirms the importance of the perivenous areolar tissue for survival of the venous skin flap in the rabbit ear model.

RECONSTRUCTION OF FINGER DEFECTS WITH PEDICLED VENOUS ISLAND FLAP

Reconstruction of a injured digit needs good aesthetic result as well as functional recovery. Since Honda deported the first clinical application in 1984, the venous flap has been used increasingly for skin and soft tissue defects of the fingers and hands. From november 1992 to december 1995, 12 single-pedicled venous island flaps from hand dorsum were used for coverage of soft tissue defects of fingers over exposed bone, tendon, or joint. The pedicle of the flap included one superfitial dorsal vein of hand and its perivenous areolar tissue. Eight of twelve flaps survived completely and four necrosed partially possibly due to excessively long pedicle and poor perivenous areolar tissue. All donor sites were closed directly. Most patients were satisfied with postoperative result cosmetically and functionally. This method has several advantages : easy versatility and operability with superficial location of numerous dorsal vein, making good contour owing to proper thickness of flap, minimal donor site morbidity, and short operation time. We consider that the pedicled venous island flap is another reliable and useful method for reconstruction or finger defects as long as the pedicle length is not long and the perivenous areolar tissue is enough.