Viability of five different pre- and intraoperative imaging methods for autologous breast reconstruction.

BACKGROUND: Autologous breast reconstruction is an integral part in the treatment of breast cancer. While computed tomography angiography (CTA) is an established preoperative diagnostic tool for microsurgeons, no study has so far evaluated and compared five different imaging methods and their value for the reconstructive team. In order to determine the feasibility of each of the tools for routine or specialized diagnostic application, the methods' efficiency and informative value were analyzed. METHODS: We retrospectively analyzed imaging data of 41 patients used for perforator location and assessment for regional perfusion and vessel patency in patients undergoing autologous breast reconstruction with deep inferior epigastric perforator flap (DIEP), transverse rectus abdominis muscle flap (TRAM), or transverse myocutaneous gracilis flap (TMG). Five different imaging techniques were used: hand held Doppler (HHD), CT angiography (CTA), macroscopic indocyanine green (ICG) video angiography, microscope-integrated ICG video angiography, and laser Doppler imaging (LDI). RESULTS: CTA proved to be the best tool for preoperative determination of the highly variable anatomy of the abdominal region, whereas HHD showed the same information on perforator localization with some false-positive results. Intraoperative HHD was an excellent tool for dissection and vessel patency judgment. Microscope-integrated ICG was an excellent tool to document the patency of microanastomoses. In our series, macroscopic perfusion measurement with ICG or LDI was only justified in special situations, where information on perfusion of abdominal or mastectomy flaps was required. LDI did not add any additional information. CONCLUSION: Preoperative assessment should be performed by CTA with verification of the perforator location by HHD. Intraoperative HHD and microscope-integrated ICG contribute most toward the evaluation of vessel patency. ICG and LDI should only be used for special indications.

Effective local anaesthetic volumes for sciatic nerve blockade: a clinical evaluation of the ED99.

Previous results in volunteers have indicated the effective dose in 99% of subjects (ED99 ) of local anaesthetic volume to be 0.10 ml.mm(-2) of cross-sectional nerve area for sciatic nerve blockade. The objective of this prospective, randomised, double-blind study was to investigate the ED99 of local anaesthetic for ultrasound-guided sciatic nerve blockade in patients undergoing foot surgery, according to Dixon's up-and-down method and probit analysis. A starting volume of 0.20 ml local anaesthetic per mm(2) cross-sectional nerve area was used. If surgical anaesthesia was judged to be adequate, the volume of local anaesthetic for the next case was reduced by 0.02 ml.mm(-2), until the first block failed. Thereafter, the volume of local anaesthetic was increased by 0.02 ml.mm(-2). The ED99 volume of local anaesthetic for ultrasound-guided sciatic nerve blockade was calculated to be 0.15 ml.mm(-2) cross-sectional nerve area, which is higher than the previously evaluated ED99 volume in volunteers.

Objective and subjective evaluation of donor-site morbidity after nipple sharing for nipple areola reconstruction.

Nipple reconstruction is of importance in achieving the best possible aesthetic outcome after breast reconstruction. Nipple sharing is a common technique; this study focused on the potential morbidity at the donor nipple. Between 2008 and 2012, 26 patients underwent nipple sharing at our institution. The donor nipple was examined before and after the procedure (mean follow-up of 21 months). Sensitivity, projection, diameter, and patient satisfaction were evaluated. The sensitivity in the donor nipple decreased, albeit insignificantly, from 1.2 g/mm2 (0.8-1.6) to 1.8 g/mm2 (0.8-4.8) (p=0.054, n=26). The projection due to graft removal decreased from 8.0 mm (6.8-10.0) to 4.5 mm (4.0-5.0) (p=0.001). Of the patients, 88% were "very satisfied" or "somewhat satisfied" with the sensitivity and 89% with the symmetry between the donor and reconstructed nipple. At least 60% of the patients were "very satisfied" with all aesthetic outcome parameters (projection, appearance, naturalness, color, and shape). All patients would agree to undergo this procedure again, if necessary. Nipple sharing was associated with minimal morbidity at the donor nipple. The postoperative projection was adequate. Regardless of whether simultaneous mastopexy was performed, the loss of sensitivity was minimal and presumably imperceptible to the patient. By using no sutures after graft removal and letting the donor nipple heal spontaneously, scarring was minimized and the natural appearance and good sensitivity of the donor nipple were preserved.

Port-a-Cath extravasation of vesicant cytotoxics: surgical options for a rare complication of cancer chemotherapy.

BACKGROUND: Although implantation of a central venous device such as a Port-a-Cath was initially considered safe, extravasation rates up to 4.7% have been reported. Therefore, the objective of this study was to propose a structured procedure for the management of extravasation of a cytotoxic treatment. METHODS: A total of eight patients were evaluated after port extravasation of epirubicin (n = 3), platinum compounds (n = 3), paclitaxel (n = 1), or trabectedin (n = 1) into the subcutaneous space. Immediate explantation of the port was performed in combination with a "Subcutaneous Wash-Out Procedure" (SWOP). When removal of the port was delayed, débridement and flap coverage were performed as necessary. Epirubicin concentrations present in the samples obtained during surgical intervention were subsequently analysed using high-performance liquid chromatography (HPLC). Patients were followed for at least six months and were examined for sequelae such as pain, induration, redness, and limited movement. RESULTS: All three patients whose extravasation event was detected during chemotherapy administration benefited from SWOP with acceptable side effects (e.g., erythema). The analysis of epirubicin concentrations demonstrated the active removal of relevant amounts of the compound by wound rinsing. In contrast, late detection of extravasation led to major débridement and flap coverage in four out of five patients. A high body mass index (BMI) value was associated with all of the patients that experienced port extravasation. CONCLUSION: Depending on when Port-a-Cath extravasations into subcutaneous tissue are detected, different treatments are appropriate. When extravasation is detected early, the SWOP was found to be beneficial.

[Squamous cell carcinoma in Dupuytren's disease--a case report]. / Höherdifferenziertes verhornendes Plattenepithelkarzinom in einer Palmarfibromatose (M. Dupuytren)--Fallbericht.

Squamous cell carcinoma in the palm is an extremely rare entity. In the following case report we describe the occurrence of a squamous cell carcinoma in the presence of Dupuytren's disease. A 49-year-old man was operated on the right hand for ulcerating Dupuytren's disease. A squamous cell carcinoma was diagnosed by performing obtaining a fast section intraoperatively. The patient had an invasive, highly differentiated keratinizing squamous cell carcinoma. The lesion was resected together with the Dupuytren lesion and the defect covered with a full-thickness graft. Postoperatively the patient was irradiated. He is free of recurrence for three years now. To our knowledge, this is the first published report of a squamous cell carcinoma in the presence of Dupuytren's disease.

[Free functional muscle transplantation for facial reanimation: experimental comparison between the one- and two-stage approach]. / Experimentelle freie funktionelle Muskeltransplantation zur Reanimation des Gesichtes: Vergleich zwischen einzeitigem und zweizeitigem Vorgehen am New-Zealand-White-Kaninchen.

PURPOSE/BACKGROUND: To investigate functional results of either one- or two-staged free muscle transplantation, the scutuloauricularis model in the New Zealand white rabbits was used. METHOD AND MATERIAL: 30 rabbits were divided into 2 groups with 15 animals each. In group 1 (one-stage approach) the peroneus brevis (PB) muscle was harvested as a free muscle graft with a 7-cm long motor branch. The graft was positioned in the place of the right scutuloauricularis (SCUT) and its vascular supply microsurgically re-established. The motor branch was transferred to the contralateral side and its proximal end coapted to the cut facial motor branch to the left SCUT. Before nerve coaptation, biopsies were harvested from the cut motor branch for morphological analysis. In group 2 (two-stage approach) a 7-cm long saphenous nerve graft was taken and coapted to the cut motor branch of the SCUT and crossed over to the contralateral side. Nerve specimens from the cut motor branch were taken. Eight months later, free transplantation of the PB was performed and its motor branch coapted to the distal end of the cross-over nerve graft. After a total time period of 13 months the final experiments were carried out in each group. Maximal tetanic tensions in the reinnervated PB were measured and biopsies of muscle grafts together with nerve biopsies from the distal part of the motor branch were harvested for morphological analysis. RESULTS: Muscle grafts of group 1 revealed tetanic tension values of 12.5 N (SD 3.1) in comparison to 10.6 N (SD 3.5) obtained in group 2. This difference was not statistically significant (p = 0.303). In group 1 the amount of regenerated nerve fibres counted at the distal motor branch site (mean: 2798, SD 1242) was significantly higher (p = 0.008) than in group 2 (mean: 1138, SD 1004). Muscle graft morphology revealed significantly less type I fibres (p = 0.016) and more type II b/d fibres (p = 0.011) in group 1 compared to group 2. However, the overall amount of perimysial connective tissue showed no significant difference in both groups (p = 0.478). CONCLUSION: Free muscle transplantation in a one-stage approach offers similar functional results in comparison to the two-stage approach. Although muscle grafts of the one-stage transplantation underwent a longer period of denervation, similar contents of perimysial connective tissue could be observed.

The treatment of deep dermal hand burns: How do we achieve better results? Should we use allogeneic keratinocytes or skin grafts?

The treatment of deep dermal burns has a broad spectrum and has been subject to discussion over the past years. The treatment of hand burns is challenging due to the high requirements to aesthetic and functional outcome. 27 patients, 7 women and 20 men with deep dermal hand burns with a mean age of 41.3+/-16.5 and a mean TBSA of 15%+/-19.6% were treated either with allogeneic cryopreserved keratinocytes or with split skin grafts. Long-term follow-up revealed no statistical significant differences between the two groups concerning Vancouver Scar Scale as well as hand function judged by the DASH score; however there was a tendency to higher VSS scores and impaired aesthetic results in the keratinocyte group. Allogeneic keratinocytes are a suitable armentarium for the treatment of deep dermal hand burns; and, if used correctly, they can produce a timely healing comparable to split-thickness skin grafts. Limited availability, high costs as well as the need for special skills are key factors, which render application of this technique outside specialist burn centres virtually impossible. In our opinion, the cultivation and use of keratinocytes should be reserved to these centres in order to facilitate a sensible application for a full range of indications. We recommend usage of allogeneic keratinocytes for deep dermal hand burns only in severely burned patients with a lack of donor sites. Patients with unrestricted availability of donor sites seem to profit from the application of split-thickness skin grafts according to our results.

Management of full-thickness skin defects in the hand and wrist region: first long-term experiences with the dermal matrix Matriderm.

The gold standard for the coverage of full-thickness skin defects is autologous skin grafts. However, poor skin quality and scar contracture are well-known problems in functional, highly strained regions. The use of dermal substitutes is an appropriate way to minimise scar contraction and, thereby, to optimise the quality of the reconstructed skin. The aim of this study was to evaluate the impact of the collagen-elastin matrix, Matriderm, for the single-step reconstruction of joint-associated defects of the upper extremity. Seventeen patients with full-thickness skin defects of the upper extremity were treated with the dermal substitute, Matriderm, and unmeshed skin graft in the functional critical region of the distal upper extremity in a single-step procedure. The take rate of the matrix-and-skin graft was 96%. Long-term follow-up revealed an overall Vancouver scar scale of 1.7. No limitation concerning hand function was observed; DASH-score analysis revealed excellent hand function in patients with burn injury and patients with a defect due to the harvest of a radial forearm flap achieved satisfying hand function. This matrix represents a viable alternative to other types of defect coverage and should therefore be considered in the treatment of skin injuries, especially in very delicate regions such as the joint regions. The possibility of performing a one-stage procedure is supposed to be a major advantage in comparison to a two-stage procedure.

First experiences with the collagen-elastin matrix Matriderm as a dermal substitute in severe burn injuries of the hand.

Restoring function after hand burns plays a major role in the restitution of a quality of life. Thereby the reconstructed pliability of the grafted areas is of utmost importance for good hand function. The collagen elastin matrix Matriderm was evaluated as a dermal substitute for the treatment of severe hand burns. In a series of 10 patients, mean age 43 years, TBSA 22.8%, an early debridement and immediate grafting with the matrix and unmeshed skin graft was carried out in a one-stage procedure. In the early postoperative follow up an overall take rate of 97% was observed. In contrast to conventional skin grafts, the color of the skin grafts over the matrix appeared pale in the first few days, but after 2 weeks no difference was observed. After three months, pliability of the grafted area was excellent, (mean VSS 3.2+/-1.2). Full range of motion was achieved in all hands, no blisters and no unstable or hypertrophic scars occurred. Matriderm has proved to be a dermal substitute suitable for the treatment of hand burns. We therefore consider Matriderm as a promising dermal substitute for the treatment of severe hand burns.

Free functional muscle transplantation for facial reanimation: experimental comparison between the one- and two-stage approach.

To investigate functional results of either one- or two-staged free muscle transplantation the scutuloauricularis model in the New Zealand white rabbit was used. Thirty rabbits were allocated to two groups with 15 animals each. In Group 1 (one-stage approach) peroneus brevis (PB) was harvested as a free muscle graft with a 7cm long motor branch. The graft was positioned instead of right scutuloauricularis (SCUT) and its vascular supply microsurgically re-established. The motor branch was transferred to the contralateral side and its proximal end coapted to the cut facial motor branch to left SCUT. Before nerve coaptation biopsies were harvested from the cut motor branch for morphological analysis. In Group 2 (two-stage approach) a 7cm long saphenous nerve graft was taken and coapted to the cut motor branch of SCUT and crossed over to the contralateral side. Nerve specimens from the cut motor branch were taken. Eight months later the free transplantation of PB was performed and its motor branch coapted to the distal end of the cross-over nerve graft. After a total time period of 13 months the final experiments were carried out in each group. Maximal tetanic tensions in reinnervated PB were measured and biopsies of muscle grafts together with nerve biopsies from the distal part of the motor branch were harvested for morphological analysis. Muscle grafts of Group 1 revealed tetanic tension values of 12.5N (SD 3.1) in comparison to 10.6N (SD 3.5) obtained in Group 2. This difference was not statistically significant (p=0.303). In Group 1, the amount of regenerated nerve fibers counted at the distal motor branch site (mean: 2798, SD 1242) was significantly higher (p=0.008) than in Group 2 (mean: 1138, SD 1004). Muscle graft morphology revealed significantly less Type I fibers (p=0.016) and more Type IIb/d fibers (p=0.011) in Group 1 compared to Group 2. However, the overall amount of perimysial connective tissue showed no significant difference in both groups (p=0.478). Free muscle transplantation in a one-stage approach offers similar functional results in comparison to the two-stage approach. Although muscle grafts of the one-stage transplantation underwent a longer period of denervation similar contents of perimysial connective tissue could be observed.

Intra-individual comparison between open and 2-portal endoscopic release in clinically matched bilateral carpal syndrome.

Based upon bilateral carpal tunnel syndrome (CTS) we undertook a prospective randomised intra-individual comparison between open (OR) and 2-portal endoscopic release (2-PER) to establish if there is any demonstrable advantage in undertaking either technique in a 1 year follow-up. Ten patients with bilateral CTS were enrolled in this study and underwent a 2-PER on the one and an OR with two minimised incisions on the contralateral hand. Both hands were examined pre- and postoperatively after 2, 4, 6 and 12 weeks and after 6 and 12 months, respectively. Preoperatively both hands revealed statistically no significant differences in all the parameters recorded. Comparing both techniques no significant differences could be detected in the follow-up period. Nevertheless, both techniques showed significant improvements in the severity of symptoms and pain, in sensory nerve testing and in electro-diagnostic parameters, when comparing pre- with postoperative data after 1 year. The endoscopic approach revealed no distinct advantages over the open technique not only in the late but also in the early postoperative follow-up period when performing intra-individual comparison. Considering the higher complication rate and costs when performing 2-PER the OR with two minimised incisions seems to be a good alternative in order to keep the recovery period as short as possible.

Carpal tunnel syndrome: a question of hand and wrist configurations?

This study investigated whether there is an association between hand and wrist configurations and the occurrence of carpal tunnel syndrome. The external hand and wrist dimensions of 50 subjects with carpal tunnel syndrome and 50 healthy volunteers were measured and compared. In addition carpal tunnel depth and width were determined with ultrasound. Our results showed that the hand length was significantly higher in the control group (hand length, 19.0; SD, 1.0 cm: patients' hand length, 18.2; SD, 1.1cm) and the palm width was significantly greater in the patients' group (palm width, 9.1; SD, 0.7 cm: controls palm width, 8.6; SD, 0.6 cm). Carpal tunnel syndrome patients had a squarer wrist (wrist ratio, 0.72; SD, 0.1) and carpal tunnel (carpal tunnel ratio, 0.48; SD, 0.1) than the controls (wrist ratio, 0.68; SD, 0.1; carpal tunnel ratio, 0.42; SD, 0.1). These findings indicate that the anatomy of the hand, wrist and carpal tunnel may predispose to carpal tunnel syndrome.

[The use of subatmospheric pressure to prevent burn wound progression: first experiences in burn wound treatment]. / Der Einsatz der V.A.C.-Therapie bei der Verminderung des "Nachbrennens": Erste Ergebnisse in der Verbrennungsbehandlung.

Thermal injury applied to living tissue results in zones of injury. Cell death is complete in the zone of coagulation. Beneath this area, there is the zone of lesser injury, where most of the cells are initially viable. If this zone of stasis is not reversed, the burn wound will progress. One of the major aspects to prevent progression is to reduce the edema formation and to preserve microcirculation. We present our first experiences to prevent the progression by use of topical negative pressure. Within the last months, all patients with bilateral partial thickness hand burns were included into this treatment protocol. Within one patient, one hand was treated with the V.A.C. (KCI, Austria), the contra lateral one by use of Flammazine (Smith and Nephew, Germany). Our first observations and data indicate, that both important factors (edema and microcirculation) could be influenced positively by use of the V.A.C.

The influence of dressings and ointments on the qualitative and quantitative evaluation of burn wounds by ICG video-angiography: an experimental setup.

Burn wound depth is difficult to determine. Even for experienced investigators the exact differentiation between superficial and deep dermal burns is not always possible. Therefore, methods for objective and reproducible measurements estimating the depth of burn wounds are of great clinical interest. One technique that appears to be able to differentiate between superficial and deep dermal burn wounds is ICG video-angiography. Since burn wounds are often covered with dressings and ointments or soiled with blood, it is necessary to evaluate the influence of these substances on ICG video-angiography and its performance as a measurement method. The most commonly used ointments and dressings were tested. All studied substances had a massive influence on ICG video-angiography and its measurements. They caused decreases by absorption of up to 63 +/- 36% and thereby falsely reported deeper burn wounds. The results of this study, suggest that in clinical practice, all dressings, ointments and blood should be completely removed at least 10 min prior to measurement by ICG video-angiography to gain exact and reproducible results.

Use of subatmospheric pressure therapy to prevent burn wound progression in human: first experiences.

Thermal trauma causes two different types of injuries within the burn wound. First, an immediate and irreversible injury, and, second, a delayed and partly reversible injury. It is a very common observation in burned patients that areas that initially seemed to be partial thickness burns have to be regarded as full thickness within the next day or days. The impairment of blood flow within the zone of stasis is due to the impairment of the vascular patency at the microvascular level. This progression is closely correlated to the degree of oedema formation. The aim of the study was to demonstrate that applied, controlled subatmospheric pressure is useful to prevent the progression of partial thickness burn injuries. Therefore, seven patients (mean age, 44.2 years; S.D., 22.4 years) with bilateral partial thickness hand burns were included into this treatment protocol. The more intense injured hand was treated with controlled applied subatmospheric pressure (V.A.C. (ATS)), the other and less injured hand conservatively by use of silver sulphadiazine creme. In the V.A.C.-treated hand a massive hyperperfusion was observed, being a possible reason for the prevention of burn progression. Moreover, a noteworthy amount of fluid was removed from the burn wound and a clinically obvious oedema reduction was observed in comparison to the contralateral side. In summary, we are of the opinion, that patients with partial thickness or mixed thickness burn may benefit from the application of subatmospheric pressure by reducing oedema formation and increasing perfusion.

Indocyanine green video angiographies help to identify burns requiring operation.

The key decision in the treatment of thermal injuries is the determination of the depth of the burn wound and the resultant decision on treatment options. The trend in the treatment of deep dermal and full thickness burns is toward very early excision and grafting to reduce the risk of infection, decrease scar formation, shorten hospital stay, and thereby reducing costs. Traditionally, this has involved serial clinical examinations, which involves primarily subjective judgment. Various objective examination techniques, supplementing the clinical diagnosis, have been suggested, but none has yet achieved widespread clinical acceptance. It has frequently been postulated that the blood flow in injured tissue indicates the extent of tissue damage. In this study, the clinical and scientific impact of indocyanine green (ICG) video angiography was tested in 20 patients. A wide range of depth of injury and etiology was included and analyzed. In all cases considered, video angiography was possible. The measurements and observations correlated well with the actual burn depth, which was assessed clinically (pre- and intraoperative assessment) and histologically (biopsies). In conclusion, ICG video angiography seems to be a practical method to describe vascular patency in a burn wound. The results indicate that ICG fluorescence angiography is a practical, accurate, and effective adjunct to clinical methods for estimating burn wound depth and thereby to assist in the rational assessment of treatment options. Furthermore, it allows an objective, qualitative and quantitative observation of the dynamic changes in burn wound depth, which are observed during the acute post-burn period, thereby indicating optimal timing of the first operation.

Continuous free-flap monitoring with tissue-oxygen measurements: three-year experience.

Early recognition of flap failure is a prerequisite for flap salvage. Many methods are used to monitor free flaps. The time interval for re-establishing vascular patency is the limiting factor for a successful revision. Prompt re-operation and a rapid and sufficient correction of the microvascular anastomosis are necessary to maintain flap viability. The Licox Catheter pO 2 Micro-Probe instrument is used for continuous determination of oxygen partial pressure (pO 2 ) in body fluids and tissue (p ti O 2 ). Over a period of 3 years, 60 free tissue transfers to head and neck, trunk, and upper and lower extremities were monitored using the Licox Catheter Probe System. The flexible Licox Catheter pO 2 Micro-Probe detected circulatory changes and failure in all cases, with no false positives or negatives. In all cases in which the arterial pedicle failed, the p ti O 2 dropped rapidly; in cases of venous insufficiency, the p ti O 2 value decreased more or less slowly. In all failing flaps, a p ti O 2 decrease of 10 mmHg within a half-hour, or a p ti O 2 drop below 10 mmHg was observed. These are observations which are useful as precise indicators for vascular complications and flap failure. Based on the authors' observations and data, the Licox probe is a sensitive and accurate monitoring system for all types of free flaps.

The influence of timing on the functional and morphological result after nerve grafting: an experimental study in rabbits.

Clinical experience and experimental work in sheep have shown that a two-stage approach to restoring muscle function with a long nerve graft and free muscle grafting seems to be more beneficial than a one-stage approach. Based on a standardised experimental protocol, one-stage and two-stage nerve grafting approaches in rabbits were compared, and the actual differences in muscle force, together with morphological data, were calculated. In 20 rabbits the saphenous nerve was used as a 7 cm nerve graft. Animals were separated into two groups. In group 1, 10 rabbits underwent a one-stage approach to reinnervate the rectus femoris muscle. In the left hindlimb, the proximal end of the graft was coapted to the cut motor nerve branch of the vastus medialis muscle, and the distal end was coapted to the nerve branch of the rectus femoris muscle. In group 2, 10 rabbits underwent a two-stage approach, leaving the distal end of the nerve graft unconnected to the rectus femoris muscle in the first stage. In the second stage, this end was coapted to the freshly cut motor nerve branch of the rectus femoris muscle. After 15 months, the maximum tetanic tensions in the reinnervated rectus femoris muscle and the contralateral unoperated muscle were determined. The graft and the motor branch distal to the graft were biopsied in order to count the number of regenerated myelinated nerve fibres. The mean+/-s.d. maximum tetanic tensions in the reinnervated rectus femoris muscles were 10.6+/-4.9 N in group 1 and 21.4+/-1.1 N in group 2. Compared with the unoperated side, the muscle force following denervation and reinnervation was 38.3% in group 1 and 58.9% in group 2 (P=0.01). The mean+/-s.d. numbers of regenerated myelinated nerve fibres distal to the graft in the rectus femoris muscle branch were 737+/-340 in group 1 and 1487+/-1004 in group 2 (P=0.05). These results show that the neurotrophic effect of an immediately connected target organ is far outweighed by the adverse effect of the longer period of muscle denervation. Therefore, nerve grafting and muscle transplantation should not be performed in the same operation.

Functional and morphometric evaluation of end-to-side neurorrhaphy for muscle reinnervation.

This study was undertaken to quantify the effect of motor collateral sprouting in an end-to-side repair model allowing end organ contact. Besides documentation of the functional outcome of muscle reinnervation by end-to-side neurorrhaphy, this experimental work was performed to determine possible downgrading effects to the donor nerve at end organ level. In 24 female New Zealand White rabbits, the motor nerve branch to the rectus femoris muscle of the right hindlimb was dissected, cut, and sutured end-to-side to the motor branch to the vastus medialis muscle after creating an epineural window. The 24 rabbits were divided into two groups of 12 each, with the second group receiving additional crush injury of the vastus branch. After a period of 8 months, maximum tetanic tension in the reinnervated rectus femoris and the vastus medialis muscles was determined. The contralateral healthy side served as control. The reinnervated rectus femoris muscle showed an average maximum tetanic force of 24.9 N (control 26.2 N, p = 0.7827), and the donor- vastus medialis muscle 11.0 N (control 7.3 N, p = 0.0223). There were no statistically significant differences between the two experimental groups (p = 0.9914). The average number of regenerated myelinated nerve fibers in the rectus femoris motor branch was 1,185 +/- 342 (control, 806 +/- 166), and the mean diameter was 4.6 +/- 0.6 microm (control, 9.4 +/- 1.0 microm). In the motor branch to the vastus medialis muscle, the mean fiber number proximal to the coaptation site was 1227 (+/-441), and decreased distal to the coaptation site to 795 (+/-270). The average difference of axon counts in the donor nerve proximal to distal regarding the repair site was 483.7 +/- 264.2. In the contralateral motor branch to the vastus medialis muscle, 540 (+/- 175) myelinated nerve fibers were counted. In nearly all cross-section specimens of the motor branch to the vastus medialis muscle, altered nerve fibers could be identified in one fascicle distal and proximal to the repair site. The results show a relevant functional reinnervation by end-to-side neurorrhaphy without functional impairment of the donor muscle. It seems to be evident that most axons in the attached segment were derived from collateral sprouts. Nonetheless, the present study confirms that end-to-side neurorrhaphy is a reliable method of reconstruction for damaged nerves, which should be applied clinically in a more extended manner.

Histomorphology of rabbit thigh muscles: establishment of standard control values.

The thigh muscles of New Zealand White (NZW) rabbits are frequently used in experimental surgery, particularly for evaluation after reinnervation or ischaemia. Although histomorphometric analyses are regularly performed, morphological data for untreated thigh muscles in previously unoperated animals are not available. Specimens from the rectus femoris (RF), vastus medialis (VM) and adductor magnus (AM) muscles from both thighs were harvested in 7 untreated rabbits and were processed for histomorphometric evaluation. The right RF and VM were harvested in a further 5 rabbit hindlimbs after experimental denervation and reinnervation of the contralateral RF and subsequently processed for histomorphometric analysis. Muscle fibre type distribution, diameter and connective tissue content were evaluated on serial transverse cryosections reacted for ATPase and NADH tetrazolium reductase activity and statistical analysis was performed. In all untreated animals RF revealed the highest proportion of type I muscle fibres (right: 8.4+/-4%, left: 11.4+/-4.9%), whereas VM showed the highest percentage of IIa fibres (right: 31.9+/-5.5%, left: 28.3+/-7.8%) and AM the highest proportion of IIb/d fibres (right: 80.5+/-8.6%, left: 84.4+/-6.3%). Fibre type distribution and diameter in rabbits after contralateral experimental operations revealed a statistically significant difference from the data obtained in bilaterally untreated animals. Knowledge of the morphology of untreated muscles is fundamental to the understanding of changes induced by intervention to the ipsi and/or contralateral thigh muscles.