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Traumatic amputation of the entire auricle is a rare occurrence. Management ideally consists of microvascular reconstruction of auricular arterial, venous, and nerve continuity. However, appropriately sized veins are often not available and venous drainage must be accomplished with leech therapy. In occasional cases where leeches are unavailable or cannot be made to attach, mechanical drainage and anticoagulation can give satisfactory drainage. The authors present a case of mechanical wick venous drainage of a complete ear replantation, resulting in virtually normal appearance and function of the ear. In addition, the ear regained normal touch and two-point sensibility, although the great auricular nerve had not been repaired.© 1998 Wiley-Liss, Inc. MICROSURGERY 18:282-285 1998Replantation of severed digits and other body parts has become commonplace with the use of advanced microsurgical techniques. Amputated ears have unique anatomic features that both impede and facilitate successful replantation. 1 Previous case reports have emphasized venous congestion as a major complication hindering otherwise technically successful reattachment of avulsed ears.2-6 We present a case report of successful complete ear replantation without venous anastomosis, which was salvaged through the use of anticoagulation and mechanical venous drainage after medicinal leech therapy had failed. CASE REPORTA 25-year-old man was involved in a single-vehicle motor vehicle accident resulting in complete avulsion of the right ear at the level of the external auditory meatus (Fig. 1). He suffered only minor soft-tissue injury to the left shoulder in addition. There was no indication of intracranial, thoracic, or abdominal injury. The ear was placed in a plastic bag in iced saline and brought to the emergency room with the patient (Fig. 2). The time from injury to operating room was 3 hours.Two surgical teams cleaned and debrided the amputated part and the avulsion site simultaneously under 10× magnification. After meticulous examination of both anatomic sites, only a single vessel was found in the preauricular area of the head about 1 mm in size; a 0.5-mm vessel was located anterior to the helical root of the ear. No inferior or posterior vessels were located. Both vessels were thought to be arterial, as they were relatively thick-walled. Because of the 1-cm gap between segments, an interpositional reversed vein graft was taken from the dorsum of the left foot.The proximal arterial branch was sutured to the reversed vein graft with 10-0 interrupted nylon sutures; the distal arterial-graft anastomosis was performed with 11-0 interrupted nylon sutures. The entire ear immediately became pink, indicating successful reperfusion. At this point, a further attempt to locate bleeding veins was made; but again, none were found. The ear was attached to the head with several 4-0 chromic sutures. No drains were placed. No nerve repairs were performed.At the time of release of arterial clamps following revascularization, heparin was started and partial thr...

Decellularization removes cellular antigens while preserving the ultrastructure and composition of extracellular matrix (ECM). Decellularized ECM (DECM) scaffolds have been widely used in various tissue engineering applications with varying levels of success. The mechanical, architectural and bioactive properties of a DECM scaffold depend largely on the method of decellularization and dictate its clinical efficacy. This article highlights the advantages and challenges associated with the clinical use of DECM scaffolds. Poor mechanical strength is a significant disadvantage of some DECM scaffolds in the repair of load-bearing tissues as well as critical-size defects, where long-term mechanical support is required for the regenerating tissue. Combining DECM scaffolds with synthetic biocompatible polymers could provide a useful strategy to circumvent the issues of poor mechanical stability. This article reviews studies that have combined DECM scaffolds from various tissues with synthetic polymers to create hybrid scaffolds using electrospinning. These hybrid scaffolds provide a mechanical backbone while retaining the bioactive properties of DECM, thus offering a significant advantage for tissue engineering and regenerative medicine applications.

Leeches possess properties that make them uniquely able to assist with venous compromised tissue. Their saliva contains an anticoagulant and a histamine-like vasodilator that promote local bleeding, a local anesthetic, and hyaluronidase that promotes the local spread of the other leech salivary secretions into the wound/bite. In addition, active pharyngeal peristalsis further promotes the egress of venous blood. Resurgence in the use of leeches has been stimulated by Upton in the United States and Mahaffey in Europe. Currently, leeches are used at many microsurgical centers to provide critical venous outflow for compromised tissue replantations and transfers that might otherwise be unsalvageable. As the use of leeches becomes more widespread, knowledge of leech biology and physiology is important. This review reports on Hirudo medicinalis, the species used most often medically in Europe and the United States.

We present the use of polytetrafluoroethylene (PTFE) graft material as a microsurgical training model that better simulates live vessel repairs. PTFE grafts have mechanical advantages over polyethylene or silicone tubing in that they better mimic the "feel" of an arterial vessel wall, thus allowing the student to perfect counterpressor maneuvers before attempting live vessel repairs. Saving the PTFE "repairs" for later comparison and study provides the student with positive feedback that is not possible with living models. This cost-effective model has helped to shorten our directed teaching program and has reduced the use of laboratory animals. Microsurgery was born in the surgical research laboratory. Today, microsurgery has an impact on nearly every surgical field. As a result, ever-increasing numbers of surgeons and technicians are seeking advanced training in microsurgery.To meet these needs, dry-lab training models have been used in the early stages of training to allow perfection of microsurgical technique before beginning live vessel repairs.Traditional dry-lab microvascular teaching models have used polyethylene tubing to simulate a vessel wall for microvascular repair (Fig. l). This tubing is relatively thick and inflexible, making it a rather impractical model for training. Research efforts to manufacture artificial microvascular conduits have produced thin, smalltaliber polytetrafluoroethylene (PTFE) conduits with external diameters of 0.5 to 1.5 mm (Fig. 2). We have found that these PTFE grafts are useful as a microvascular training model. Students use the grafts for initial microvascular repair training and, later, more advanced microvascular maneuvers. This report highlights our use of PTFE grafts as a dry-lab microvascular teaching model. demonstrate proficiency with microinstruments under the operating microscope; this usually follows the completion of microsurgical knot-tying exercises. Initially, students perform simple end-to-end repairs using the 1.5 mm PTFE graft material focusing on 1) the proper distance from the cut vessel end to insert the needle, 2) the proper needle placement through the vessel wall, 3) proper placement of "stay" sutures, 4) the movement of the needle and suture through the anastomotic gap, and 5 ) the proper number of sutures and the intersuture distance along an anastomotic gap (Figs. 3, 4). MATERIALS AND METHODS Segments ofStudents continue using PTFE grafts of decreasing external diameters until they master end-toend repairs of the 0.5 mm grafts. After this, they practice the techniques of repairing conduit diameter mismatches and end-to-side repairs (Fig. 5). Review of the completed "repairs" (Fig. 6) allows critical assessment of technique and an appreciation of the importance of preanastomotic planning. DISCUSSIONSince 1979, there have been many reports of the experimental use of PTFE as a microvascular graft. 1-11 Because the patency rates for PTFE grafts have not surpassed vein grafts, PTFE grafts have remained in the research laboratory. In our laboratory, sm...

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Traumatic amputation of the entire auricle is a rare occurrence. Management ideally consists of microvascular reconstruction of auricular arterial, venous, and nerve continuity. However, appropriately sized veins are often not available and venous drainage must be accomplished with leech therapy. In occasional cases where leeches are unavailable or cannot be made to attach, mechanical drainage and anticoagulation can give satisfactory drainage. The authors present a case of mechanical wick venous drainage of a complete ear replantation, resulting in virtually normal appearance and function of the ear. In addition, the ear regained normal touch and two-point sensibility, although the great auricular nerve had not been repaired.