Nerve regeneration through an epineurial sheath: its functional aspect compared with nerve and vein grafts.

Although nerve graft is still the only reliable choice in repair of defects in peripheral nerve structure, it has the disadvantage of donor nerve morbidity and of sometimes being unavailable. It has long been researched in alternate nerve grafts with other materials. Studies have shown that nerves could regenerate across short nerve gaps through various conduits, such as veins, pseudosheaths, and bioabsorbable tubes. Despite encouraging studies, their functional results remain unclear. The present study used 40 rats, in which nerve grafts, vein grafts, and epineurial tubes were placed into 1-cm gaps in sciatic nerves created by resection. In one group, sciatic nerves were denuded of the surrounding epineurium, to assess the possible morbidity caused by epineurial sheath technique. At 2, 4, 8, 12, 20, and 28 weeks, functional assessment of nerve regeneration was performed using walking track analysis. The number of myelinated fibers and fiber diameters was measured and electron microscopic evaluation performed. Functionally, the index values were very close to each other in nerve graft and epineurial sheath groups. Morphometric analysis showed significance between the groups. The result of denuded sciatic nerve group was the same as the base track values. It was concluded that the ready availability of epineurial sheath as a conduit to span short nerve gaps could eliminate the morbidity associated with nerve graft harvest and capitalize on the potential benefits of neurotrophism in directing nerve regeneration.

Wiping away debris between passes during laser surgery: is it really efficient or causing complications?

Although carbon dioxide laser skin resurfacing offers a controlled and predictive tissue ablation, it is not completely without complications, such as cobblestone-like appearance or scar formation. It has been supposed that these were the results of thermal loading on overlapped areas. In order to obtain a smoother surface, an experimental study dealing with the effect of wiping procedure between the sessions was carried out. Laser beams were applied in two sessions to the backs of 20 rats. Between the sessions, the debris was wiped away in half and left unwiped in the others. Despite a statistically higher ablation rate in the wiped group, its surface irregularity was statistically significant when compared to unwiped group. It is supposed that the amount of debris left on the surface has the regulatory role in laser application. Because laser beams can be absorbed more by untreated skipped areas and less by overlapped sites, the second pass can ensure a smoother surface. Considering both benefits and disadvantages, it is concluded that wiping vaporized debris every two passes is the most reliable laser treatment modality.

Prolonged intermittent hydrotherapy and early tangential excision in the treatment of an extensive strong alkali burn.

It is well known that the first step in the treatment of cutaneous strong alkali burn is very early and persistent washing of the site of injury with large volumes of water. However, ideal duration and the technique of hydrotherapy has not yet been established. Besides hydrotherapy, tangential excision of the injured skin might prevent further tissue damage if it is performed early enough. We report the treatment of a 36-year-old male who sustained 53% body surface area (BSA) cutaneous burn due to caustic soda (NaOH). Prolonged intermittent hydrotherapy, early tangential excision and autografting of the injured skin are the keys for the proper management of extensive strong alkali burn.

Rotation ligamentoplasty for the correction of epicanthus inversus.

Epicanthus, with its various types, is characterized by an arching fold at the sides of the nose, with a concavity directed laterally. Epicanthus inversus, one of these types, which occurs with varying frequency in all races, is most common among Asians. In epicanthus inversus, the medial canthus is displaced laterally and the medial canthal depression is shallow or absent. The lower puncta is displaced laterally as well. Correction of epicanthus is easy with Z-plasties or with the four-flap technique of Mustardé. However, inverted epicanthus cannot be repaired using these techniques, as proved by others. The authors suggest rotating the medial canthal ligament during transnasal wiring to support the eversion of the laterally displaced medial lower lid, lower puncta, and surrounding skin. Eight patients with epicanthus inversus were operated and followed for at least 15 months. The results were satisfactory according to a graded scale.

Treatment of burn scar depigmentation by carbon dioxide laser-assisted dermabrasion and thin skin grafting.

Permanent depigmentation occasionally develops after deep partial-thickness and full-thickness burn injuries, which heal by secondary intention. This problem can be solved by dermabrasion and thin split-thickness skin grafting. However, mechanical dermabrasion is a bloody procedure that risks exposing medical professionals to infectious diseases transmitted by blood products, and it is difficult to assess the extent of tissue ablation. In this study, dermabrasion of depigmented burn scar area was performed by using flash-scanned carbon dioxide laser treatment, followed by thin split-thickness skin grafting. This method was applied to 13 patients on whom burn scar depigmentation sites were located as follows: two in the facial area, four on the trunk, and seven on the extremities. Skin graft take was excellent in all patients except for one. The follow-up period for these patients ranged from 1 to 12 months, with an average of 8 months. Repigmentation appeared soon after grafting, and no depigmentation occurred again in the treated areas. In conclusion, depigmented burn scar areas can be dermabraded in a short time; depth of tissue ablation can be well controlled; and a bloodless and smooth raw surface can be created by using a flash-scanned carbon dioxide laser. These raw surfaces sustain thin skin grafts well.

Replantation of an avulsive amputation of a foot after recovering the foot from the sea.

A foot avulsion case, with the dismembered body part submerged in sea water for 1 hour, is presented. This report is unique in that it is the first to document the reattachment of a body part that had been submerged in sea water. It was not known how salt-water exposure would affect wound management. Differences in osmolarity and bacterial flora between the sea water and foot tissues have not caused any problems, and the patient has not suffered any vascular or infectious complications after replantation. Neurotization of the plantar surface by the tibial nerve, which was stripped off during amputation and replaced in its original traces, was the most critical part of convalescence. After management of such an interesting case, we conclude that exposure to sea water of the dismembered part should not be a contraindication for replantation surgery.

Nerve regeneration through side-to-side neurorrhaphy sites in a rat model: a new concept in peripheral nerve surgery.

Despite great improvement and refinements in nerve repair techniques, there were still problems in repair of peripheral nerve injuries for which proximal stumps were not available. In these circumstances for which classic end-to-end neurorrhaphy was impossible, new treatment modalities, benefiting by an adjacent healthy nerve, have been under investigation to overcome this problem. Therefore, end-to-side nerve repair with its modifications came to view and axonal passages through this site were shown. Moreover, the results were unsatisfactory or necessitating sacrifice of another healthy nerve. Three groups, containing 10 rats each, were included in the study. First was the control group, with end-to-end repair of the peroneal nerve. Second was the end-to-side repair group, in which the distal stump of the peroneal nerve trunk was anastomosed to the lateral side of the tibial nerve. The third was the side-to-side repair group. In this technique, 1-mm diameter epineural windows, both from peroneal and tibial nerve trunks facing each other, were removed and side-to-side neurorrhaphy was performed. After 3 weeks, as the second step, the peroneal nerve was sectioned proximally. At 2, 4, 8, 12, 20, and 28 weeks, functional assessment of nerve regeneration was performed by using walking track analysis. The number of myelinated fibers and fiber diameters were measured and an electron microscopic evaluation was carried out. Statistically, both in morphometric and gait analysis, the differences in values between the groups were significant in favor of the control group, followed by the side-to-side group. The study showed that axonal passage was possible with side-to-side technique and the functional results were satisfactory and superior to the end-to-side technique. Continuous supply of neurotrophic factors from their target cells was the probable cause of superior functional return in side-to-side repair, because both joining nerves were intact and healthy during the anastomosis procedure and after 3 weeks. It was concluded that this technique could be indicated in salvage of nerves in cases for which any intermediate segments would be removed, as in tumor ablation surgery, harvesting of nerve grafts, or both.

Prevention of restrictive adhesions in primary tendon repair by HA-membrane: experimental research in chickens.

Hyaluronic acid (HA) is a glycosaminoglycan polymer that has been found to have some beneficial effects on the prevention of adhesions in primary tendon repairs. The need for slow elimination preparations of HA has been identified. We have combined HA and carboxymethylcellulose (CMC) in order to get a slow elimination preparation of HA and studied its possible effect on primary tendon healing. A gel form of NaHe (19 mg/ml; mw: 6.5 x 10(6)) was mixed with Na CMC (degree of substitution: 0.8) under sterile conditions. A jelly like mixture was thinned and HA membrane was achieved after drying in the refrigerator. The right legs of Leghorn chickens (n = 30) were prepared under IM ketamine anaesthesia by making partial cuts (75%) of flexor profundus tendons at zone II in the second, third and fourth toes, and repaired using a modified Kessler type suture (5/0 nylon). HA-membranes were applied around the repair sites in the third toes while 0.5 ml of hyaluronic acid and saline were poured on to the repair sites in the second and fourth toes, respectively. Skin incisions were closed and the legs were splinted for 15 days. Biomechanical and histological controls were made at the first, second and third postoperative months. No wound dehiscence or exposure of repaired tendons was observed on the operated toes. After collection of samples by amputation at MP levels, two-phalanx free biomechanical assessment was done. The calculated peaks of differential joint motion were very similar to the corresponding non-operated contralateral toes in the HA-membrane treated group. The toe tip displacement curves also resembled the non-operated ones in this group. HA membrane was detected as blue particles on specimens taken at the 30th day following surgery. There were few adhesions in this group microscopically at the third month. Adhesions were similar in the HA treated group while dense adhesions were seen in the saline treated group. These findings suggest that HA membrane acting as a physicochemical barrier can prevent restrictive adhesions in primary tendon repairs.

Three-dimensional reconstruction of types IV and V midfacial defects by free rectus abdominis myocutaneous (RAM) flap.

Extensive midfacial defects after ablative surgery constitutes a challenging problem for reconstructive surgeons. Particularly for types IV and V midfacial defects, provision of missing bony support and obliteration of the maxillary cavity defects require microsurgical free tissue transfers. In the last three years, four patients have undergone total maxillectomy for midfacial tumours and the postmaxillectomy defects were three-dimensionally repaired with free rectus abdominis muscle flap and skin graft or myocutaneous flaps. Obliteration of maxillary cavity defects and orbital support were achieved with this type of free flap. The least follow-up period of the patients is one year and slight ectropion, later corrected, was seen in two patients. In this study, the free rectus abdominis myocutaneous (RAM) flap, with its long vascular pedicle and availability of various skin paddle designs and muscle bulk, is presented in treatment of extensive midfacial defects. In spite of initial overcorrection of contour, the denervated rectus abdominis muscle gradually atrophies, resulting in loss of contour. The muscle bulk fills the cavity defect, but, in order to achieve good facial contour, it is necessary to support the bony skeleton with some material.

Salvage of foot amputation stumps of Chopart level by free medial plantar flap.

Blast energy-induced traumas usually result in some type of amputations of lower extremities. It is very hard to determine the amputation level of the feet of these cases at first, and secondary amputation stump revisions by bone shortening are often necessary. Among partial foot amputation levels, Chopart level is the most critical. Four male patients (20 to 24 years old) with modified Chopart amputation due to mine explosion injury have had skin-grafted amputation stumps where troublesome, recurrent unstable wounds had developed. These amputation stumps were electively reconstructed with neurosensorial free medial plantar flaps from unaffected feet without any bone shortening. All the transferred flaps survived and adapted to stumps well, and patients were ambulated at the second month by wearing on the original prosthesis after minimal adjustments. At the follow-up period (6 months to 2 years), no skin breakdown of the stumps was evident. Monofilament (Semmes-Weinstein) tests revealed diminished light touch in two patients and diminished protective sensation in another two patients at the sixth month. Temporary donor foot pain, which existed by walking for 3 months, may be due partly to absence of plantar fascia supporting the plantar arc. We suggest that amputation level of Chopart is the most critical of partial foot amputations in young patients and should be reconstructed with flaps if there is not sufficient soft-tissue coverage of amputation stump; free neurosensorial medial plantar flap would be the primary choice with its advantages.

Reconstruction of anterior neck contractures with sensate expanded radial forearm free flap.

The surgical management of anterior neck contractures, related to burn injuries, is a challenging problem for reconstructive surgeons. The use of sensate expanded radial forearm fasciocutaneous free flaps in two patients suffering from anterior burn contractures of the neck is presented as an alternative method of surgical management. The advantages of employing sensate expanded radial forearm free flaps to reconstruct anterior neck contractures are also discussed in this paper.

Canniesburn "ever-ready" model to practise microsurgery.

An experimental model is described to practise microsurgery with material readily available in any routine operating theatre. By using a simple mathematical formula of C = pi x D, tubes of different diameters can be constructed for either end-to-end or end-to-side anastomoses.