[Dog population and dog breeds in Switzerland from 1955 to 2008]. / Hundepopulation und Hunderassen in der Schweiz von 1955 bis 2008.

Aim of this study is to present a survey of the dog population and breed distribution in Switzerland from 1955 to 2008 as basis to realize a population based canine cancer register for Switzerland. The number of dogs rose from 309'000 in 1955 to approximately 500'000 in 2008 correlating with a parallel increase of human population. The ratio of dogs per 100 inhabitants remains stable. This ratio is lower in German speaking compared to French or Italian speaking Cantons. The variety and popularity of breeds changed from 1955 to 2008, "winners" are Labrador and Golden Retrievers, Yorkshire and Jack Russel Terriers. Less popular breeds over the years are German Sheherd dogs and Poodles.

Relevance of the light line in planar photonic crystal waveguides with weak vertical confinement.

The concept of the so-called light line is a useful tool to distinguish between guided and non-guided modes in dielectric slab waveguides. Also for more complicated structures with 2D mode confinement, the light lines can often be used to divide a dispersion diagram into a region of a non-guided continuum of modes, a region of discrete guided modes and a forbidden region, where no propagating modes can exist. However, whether or not the light line is a concept of practical relevance depends on the geometry of the structure. This fact is sometimes ignored. For instance, in the literature on photonic crystal waveguides, it is often argued that substrate-type photonic crystal waveguides with a weak vertical confinement are inherently lossy, since the entire bandgap including the line defect modes is typically located above the light line of the substrate. The purpose of this article is to illustrate that this argument is inaccurate and to provide guidelines on how an improved light line concept can be constructed.

Morphology and hemodynamics during vascular regeneration in critically ischemic murine skin studied by intravital microscopy techniques.

BACKGROUND: With the understanding of angiogenesis and arteriogenesis, new theories about the orchestration of these processes have emerged. The aim of this study was to develop an in vivo model that enables visualization of vascular regenerating mechanisms by intravital microscopy techniques in collateral arteriolar flap vascularity. METHODS: A dorsal skin flap (15 × 30 mm) was created in mice and fixed into a skinfold chamber to allow for assessment of morphology and microhemodynamics by intravital fluorescence microscopy (IVFM). Laser scanning confocal microscopy (LSCM) was utilized for three-dimensional reconstruction of the microvascular architecture. RESULTS: Flap tpO(2) was 5.3 ± 0.9 versus 30.5 ± 1.2 mm Hg in controls (p < 0.01). The collateral arterioles in the flap tissue were dilated (29.4 ± 5.3 µm; p < 0.01 vs. controls) and lengthened in a tortuous manner (tortuosity index 1.00 on day 1 vs. 1.35± 0.05 on day 12; p < 0.01). Functional capillary density was increased from 121.00 ± 25 to 170 ± 30 cm/cm(2) (day 12; p < 0.01) as a result of angiogenesis. Morphological evidence of angiogenesis on capillary level and vascular remodeling on arteriolar level could be demonstrated by IVFM and LSCM. CONCLUSIONS: Present intravital microscopy techniques offer unique opportunities to study structural changes and hemodynamic effects of vascular regeneration in this extended axial pattern flap model.

A self-matched leaky-wave antenna for ultrahigh-field magnetic resonance imaging with low specific absorption rate.

The technology of magnetic resonance imaging is developing towards higher magnetic fields to improve resolution and contrast. However, whole-body imaging at 7 T or even higher flux densities remains challenging due to wave interference, tissue inhomogeneities, and high RF power deposition. Nowadays, proper RF excitation of a human body in prostate and cardiac MRI is only possible to achieve by using phased arrays of antennas attached to the body (so-called surface coils). Due to safety concerns, the design of such coils aims at minimization of the local specific absorption rate (SAR), keeping the highest possible RF signal in the region of interest. Most previously demonstrated approaches were based on resonant structures such as e.g. dipoles, capacitively-loaded loops, TEM-line sections. In this study, we show that there is a better compromise between the transmit signal [Formula: see text] and the local SAR using non-resonant surface coils generating a low electric field in the proximity of their conductors. With this aim, we propose and experimentally demonstrate a leaky-wave antenna implemented as a periodically-slotted microstrip transmission line. Due to its non-resonant radiation, it induces only slightly over half the peak local SAR compared to a state-of-the-art dipole antenna but has the same transmit efficiency in prostate imaging at 7 T. Unlike other antennas for MRI, the leaky-wave antenna does not require to be tuned and matched when placed on a body, which makes it easy-to-use in prostate imaging at 7 T MRI.

Optical phase locked loop for transparent inter-satellite communications.

A novel type of optical phase locked loop (OPLL), optimized for homodyne inter-satellite communication, is presented. The loop employs a conventional 180? 3 dB optical hybrid and an AC-coupled balanced front end. No residual carrier transmission is required for phase locking. The loop accepts analog as well as digital data and various modulation formats. The only requirement to the transmitted user signal is a constant envelope. Phase error extraction occurs through applying a small sinusoidal local oscillator (LO) phase disturbance, while measuring its impact on the power of the baseband output signal. First experimental results indicate a receiver sensitivity of 36 photons/bit (-55.7 dBm) for a BER of 10 ;-9, when transmitting a PRBS-31 signal at a data rate of 400 Mbit/s. The system setup employs diode-pumped Nd:YAG lasers at a wavelength of 1.06 mum.

The Swiss Canine Cancer Registry: a retrospective study on the occurrence of tumours in dogs in Switzerland from 1955 to 2008.

Diagnostic records are a key feature of any cancer epidemiology, prevention or control strategy for man and animals. Therefore, the information stored in human and animal cancer registries is essential for undertaking comparative epidemiological, pathogenic and therapeutic research. This study presents the Swiss Canine Cancer Registry, containing case data compiled between 1955 and 2008. The data consist of pathology diagnostic records issued by three veterinary diagnostic laboratories in Switzerland. The tumours were classified according to the guidelines of the International Classification of Oncology for Humans on the basis of tumour type, malignancy and body location. The dogs were classified according to breed, age, sex, neuter status and place of residence. The diagnostic data were correlated with data on the Swiss general dog population and the incidence of cancer in dogs was thus investigated. A total of 67,943 tumours were diagnosed in 121,963 dogs and 47.07% of these were malignant. The most common tumour location was the skin (37.05%), followed by mammary glands (23.55%) and soft tissue (13.66%). The most common tumour diagnoses were epithelial (38.45%), mesenchymal (35.10%) and lymphoid tumours (13.23%). The results are compared with data in other canine registries and similarities in tumour distribution and incidence are noted. It is hoped that this study will mark the beginning of continuous registration of dog tumours in Switzerland, which, in turn, will serve as a reference for research in the fields of animal and human oncology.

Modal power loss coefficients for highly overmoded rectangular dielectric waveguides based on free space modes.

A simple formalism to estimate modal power loss coefficients for an overmoded rectangular waveguide with rough surfaces is presented. The method is based on small index differences where the true radiation modes are approximated by free space modes. Loss coefficients are important in order to establish more accurate channel models for, e.g., optical backplane communication systems. The theory is validated by comparing the loss coefficients of a squeezed rectangular waveguide with the loss coefficients of a slab waveguide.

Radical sternectomy and primary musculocutaneous flap reconstruction to control sternal osteitis.

OBJECTIVE: Sternal osteitis after median sternotomy is associated with considerable morbidity and mortality. The use of muscle and omentum flaps has been proved as valid adjunct to combat these severe infections. In this study we present our experience with a more radical approach. METHODS: Sternectomy consisted of the resection of the entire sternum, including the costochondral arches and the sternoclavicular joints, and was followed by the repair of the defect with musculocutaneous flaps without any restabilization of the thoracic wall. Thirteen patients received a vertical rectus abdominis musculocutaneous flap, 14 patients received a pedicled latissimus dorsi musculocutaneous flap, and 12 patients received a free latissimus dorsi musculocutaneous flap (total of 40 flaps in 39 patients of 66 patients who required surgical revision for sternal osteitis of 6078 total patients with sternotomies). RESULTS: Two patients died within 30 days after the operation (early mortality of 5.1%); however, they did not die of sternal infection, which was cured without any recurrence in all cases. Seventeen patients (44%) required secondary, mostly minor operations for local complications. Despite some paradoxic chest movements, the patient satisfaction rating was unanimously high at the long-term follow-up (0.4 to 8.5 years, median 2.3 years). The short- and long-term complication rates were similar in the three groups. CONCLUSION: We conclude that radical sternectomy and immediate musculocutaneous flap repair provided definitive control of sternal infection in even the most severe cases, thus reducing infection-related mortality. The trade-off was a substantial rate of local complications; however, these did not cause any relevant morbidity.

Free latissimus dorsi flap for chest wall repair after complete resection of infected sternum.

BACKGROUND: Radical debridement, followed by muscle flap cover, has significantly reduced morbidity and mortality of infected sternotomy wounds. The pectoralis major, rectus abdominis, and greater omentum flaps are most commonly used, whereas the latissimus dorsi muscle is rarely employed. METHODS: In 7 patients with persistent infection and necrosis of the sternum, radical and extensive debridement including the sternum, costochondral arches, manubrium and sternoclavicular joints was performed. A free latissimus dorsi flap was used for soft tissue reconstruction without additional stabilization of the chest wall. RESULTS: All flaps survived without revision of the anastomosis. In the follow-up period (22 months to 5 years) no recurrent infection was observed. Three patients died during the study period (3 to 24 months after operation) due to causes not related to sternum operation. No additional weakness, pain, or restricted movements of the shoulders due to missing sternum was observed. CONCLUSIONS: Our findings suggest that the use of free latissimus dorsi flap after complete sternectomy for infection has several advantages: it provides abundant tissue to allow radical and extensive debridement, obliterates completely the dead space, and helps to control infection. Even without additional chest wall reconstruction it gives enough stability to allow pain-free normal daily activities.

Effects of extradural anesthesia on microcirculatory blood flow in free latissimus dorsi musculocutaneous flaps in pigs.

Free musculocutaneous flaps are used frequently in plastic surgery to reconstruct soft-tissue defects after radical cancer surgery and trauma. Despite improved surgical techniques, some of these flaps fail due to insufficient blood supply. Extradural anesthesia causes both sensory (pain relief) and sympathetic (vasodilatation) block that may be advantageous in free-flap surgery. This hypothesis, however, has not yet been studied. An experimental model in pigs was developed in which clinical conditions for anesthesia and microvascular surgery on the lower extremity were simulated as closely as possible. The effects of extradural anesthesia as well as phenylephrine infusion, combined with general anesthesia, on central hemodynamics and on microcirculatory blood flow in skin and muscle of the latissimus dorsi free flap were studied. After surgery, seven animals received extradural anesthesia during stable normovolemic conditions and another seven during mild hypovolemia (10 percent blood loss). The extradural block was objectively evaluated using the temporal summation test. Thirty minutes after induction of extradural anesthesia, the animals received an intravenous infusion of phenylephrine 1 microgram/kg per minute over a period of 15 minutes. Multichannel laser-Doppler flowmetry was used to measure microcirculatory blood flow in skin and muscle of the free flap as well as in control skin and muscle on the same extremity simultaneously. In normovolemic animals, extradural block caused a 10 percent decrease in mean arterial pressure and cardiac output and an approximately 20 percent decrease in microcirculatory blood flow in both the skin and muscle of the flap (all changes were nonsignificant). In slightly hypovolemic animals, however, extradural anesthesia caused a significant decrease in cardiac output (31 percent, p < 0.01), mean arterial pressure (24 percent, p < 0.01), and in mean blood flow in the flap muscle (22 percent, p < 0.05) and skin (20 percent, p < 0.05). During phenylephrine infusion, mean arterial pressure increased significantly (p < 0.05) in both hypovolemic and normovolemic animals, while cardiac output and microcirculatory blood flow in the flap remained almost unchanged. Extradural anesthesia does not improve microcirculatory blood flow in free musculocutaneous flaps in pigs. It causes a significant decrease in cardiac output, mean arterial pressure, and microcirculatory blood flow in slightly hypovolemic animals. During phenylephrine infusion, the microcirculatory blood flow in free flaps slightly improves due to the increase in mean arterial pressure. We suggest that extradural anesthesia for microvascular surgery should be used with great caution until human data are available.

[Body contouring by removal of skin and fatty tissue]. / Körperformung durch Entfernung von Haut und Fettgewebe.

There is an increasing demand for surgical correction of the body contour in the modern society. We present a summary of the indications and techniques of the most important interventions on the abdomen, hip, thigh and arm. The operations aim at the correction of localized excesses of fat and skin tissue with liposuction and dermolipectomy. Liposuction is performed through small skin incisions, which results in minimal scar formation; and which is associated with minimal complication rates. The indication for liposuction is restricted to the conditions in which the overlying skin is capable to retract and adapt itself to the new contour. Otherwise, or if an excess of skin is the cause of the deformity, a dermolipectomy is required. In this case, the incisions are chosen in a way that the resulting scar may be hidden as well as possible.

An old dream revitalised: preconditioning strategies to protect surgical flaps from critical ischaemia and ischaemia-reperfusion injury.

The prevention of ischaemia and the adequate restitution of blood flow to ischaemic tissue are pivotal to halt the progression of cellular injury associated with decreased oxygen and nutrient supply. Accordingly, the search for novel strategies which aim at preventing ischaemia-reperfusion-induced tissue damage is still of major interest in flap surgery. Preconditioning represents an elegant approach to render the tissue more resistant against deleterious ischaemic insults. For many decades, 'surgical delay' has been the standard method of tissue preconditioning. During the last 10 years, ischaemic preconditioning was added to the repertoire of plastic surgeons to protect flaps from ischaemic necrosis. The invasiveness and expenditure of time of these procedures, however, have always been major drawbacks, hindering a wide distribution in clinical practice. Consequently, the motivation has all along been to further refine and simplify protective strategies. Recent experimental studies have now shown that efficient protection from ischaemic necrosis can also be achieved by remote preconditioning or pretreatment with chemical agents and growth factors, which mimic the action of surgical delay and ischaemic preconditioning. In addition, the local application of unspecific stressors, including both heating and cooling, have been shown to effectively improve flap microcirculation and, thus, tissue survival. In view of successful translational research, it is now time that the efficacy of these novel preconditioning procedures is proven in prospective randomised clinical trials.

The influence of local and systemic preconditioning on oxygenation, metabolism and survival in critically ischaemic skin flaps in pigs.

Stress proteins represent a group of highly conserved intracellular proteins that provide adaptation against cellular stress. The present study aims to elucidate the stress protein-mediated effects of local hyperthermia and systemic administration of monophosphoryl lipid A (MPL) on oxygenation, metabolism and survival in bilateral porcine random pattern buttock flaps. Preconditioning was achieved 24h prior to surgery by applying a heating blanket on the operative site (n = 5), by intravenous administration of MPL at a dosage of 35 microg/kg body weight (n = 5) or by combining the two (n = 5). The flaps were monitored with laser Doppler flowmetry, polarographic microprobes and microdialysis until 5h postoperatively. Semiquantitative immunohistochemistry was performed for heat shock protein 70 (HSP70), heat shock protein 32 (also termed haem oxygenase-1, HO-1), and inducible nitrc oxide synthase (iNOS). The administration of MPL increased the impaired microcirculatory blood flow in the proximal part of the flap and partial oxygen tension in the the distal part by approximately 100% each (both P<0.05), whereas both variables remained virtually unaffected by local heat preconditioning. Lactate/pyruvate (L/P) ratio and glycerol concentration (representing cell membrane disintegration) in the distal part of the flap gradually increased to values of approximately 500 mmol/l and approximately 350 micromol/l, respectively (both P<0.01), which was substantially attenuated by heat application (P<0.01 for L/P ratio and P<0.05 for glycerol) and combined preconditioning (P<0.01 for both variables), whereas the effect of MPL was less marked (not significant). Flap survival was increased from 56% (untreated animals) to 65% after MPL (not significant), 71% after heat application (P<0.05) and 78% after both methods of preconditioning (P<0.01). iNOS and HO-1 were upregulated after each method of preconditioning (P<0.05), whereas augmented HSP70 staining was only observed after heat application (P<0.05). We conclude that local hyperthermia is more effective in preventing flap necrosis than systemic MPL administration because of enhancing the cellular tolerance to hypoxic stress, which is possibly mediated by HSP70, whereas some benefit may be obtained with MPL due to iNOS and HO-1-mediated improvement in tissue oxygenation.

Mode-locked laser diode with an ultrafast integrated uni-traveling carrier saturable absorber.

A novel two-section integrated mode-locked laser diode (MLLD) with a separate ultrafast uni-traveling carrier (UTC) saturable absorber section and semiconductor optical amplifier gain section is demonstrated. The UTC absorber is composed of a thin p-InGaAsP absorbing layer and an intrinsic InGaAsP collecting layer. By confining the photoexcitation process to the thin highly doped absorbing layer, the diffusion-limited hole extraction process is greatly enhanced. The investigated MLLD produces 600 fs uncompressed optical pulses at a 42 GHz repetition rate.

The dissection of the rectus abdominis myocutaneous flap with complete preservation of the anterior rectus sheath.

Harvesting the rectus abdominis myocutaneous flap results in defects in both the rectus abdominis muscle and the anterior rectus sheath, which may be circumvented by dissecting a perforator flap (DIEP flap) instead. However, the latter is associated with a reduction in the number of myocutaneous perforators nourishing the flap, which has been hypothesised to lead to an increased risk of partial flap failure. We present a technical modification that maintains all the feeding perforators within the flap while fully preserving the anterior rectus sheath. The anterior rectus sheath is incised along a line connecting the perforators. A muscle cuff including all the feeding perforators was raised with the flap. This technique was used in 20 consecutive patients. Nine patients underwent free TRAM flap transfers for breast reconstruction (10 flaps), and 11 patients underwent thoracic-wall reconstruction with a superiorly based pedicled flap. The median follow-up was 11 months. One patient with a pedicled flap developed a partial failure that required surgical revision; all other flaps healed spontaneously. One patient in each subset had preoperative abdominal-wall laxity that was partly corrected after surgery; no abdominal bulging or hernia occurred in the other patients. Our results suggest that the technical modification presented here may enable the surgeon to dissect a rectus abdominis myocutaneous flap with maximal perforator-related flap perfusion and minimal donor-site morbidity. An advantage over the DIEP flap is that this technique is applicable to both free and pedicled flaps.

Comparative objective and subjective analysis of temporalis tendon and microneurovascular transfer for facial reanimation.

The aim of this study was to compare objectively and subjectively the results after temporalis tendon and microneurovascular transfer for reanimation of the paralysed face. For the objective analysis, measurements of the distances between static and dynamic points in three-dimensional space were performed at rest and during smiling. The patients were assessed subjectively by non-professionals scoring videotapes. The range of motion of the oral commissure on smiling was 1.7 mm (0.8, mean and SE) after tendon and 5.5 mm (1.6) after microneurovascular transfer (P < 0.05) without showing teeth, and 0.6 mm (1.3) vs 3.6 mm (2.4, ns) with showing teeth. Compared with the healthy side, the excursions reached 6% (16) after tendon and 71% (26, P < 0.05) after microneurovascular transfer for smiling without, and -4% (14) vs 19% (14, ns) for smiling with showing teeth, respectively. Virtually no difference was found in the measurements at rest as well as in the subjective evaluation. Swelling of the cheek (28%) and tethering of the skin (24%) were shown to be the most disturbing symptoms after microneurovascular transfer. Better excursion and symmetry of the oral commissure were achieved by microneurovascular reconstruction for voluntary smile. However, the aesthetic outcome after microneurovascular transfer is markedly impaired by chronic complications including swelling of the cheek and tethering of the skin, which were not detected by the three-dimensional measurement technique used. We conclude that the aesthetic appearance should be considered equally important as the range of motion in the reanimated face.

Squamous cell carcinoma of the penile skin in a neovagina 20 years after male-to-female reassignment.

We present a patient who underwent male-to-female reassignment, and then developed squamous cell carcinoma during a complicated long-term follow-up. In very rare cases, squamous cell carcinoma may be considered in the differential diagnosis of sustained ulceration in neovaginas constructed by inverting the penile skin in male-to-female reassignments, in particular because clinical examination may be hampered by contractile scar formation of the neovaginal canal. Despite the lack of statistical evidence, it may be assumed that the heterotopic penile skin is at an increased risk of developing HPV-induced squamous cell carcinoma, especially if, over the years, there is a personal history of venereal warts.

Effects of epidural anaesthesia on microcirculatory blood flow in free flaps in patients under general anaesthesia.

It has been suggested that epidural anaesthesia may increase blood flow in free flaps on the lower extremity. The objective of the present study was to test this hypothesis in 21 patients undergoing reconstructive surgery of the lower extremity with free muscle (n = 8), fasciocutaneous (n = 6) or musculocutaneous (n = 7) flaps. Microcirculatory blood flow was measured continuously with a multichannel laser Doppler flowmetry, both in muscle and skin of the free flap as well as in the intact skin and muscle on the same extremity. After completion of surgery, general anaesthesia was continued and the epidural block was induced by an injection of 2% lignocaine-hydrochloride into a pre-operatively inserted and tested epidural catheter. The epidural block caused no change in microcirculatory flow in the intact skin and muscle, however, it resulted in a marked decrease in microcirculatory blood flow in all the free flaps studied (20-30%; P < 0.05). The epidural block also caused a significant decrease in mean arterial blood pressure, from 85 (+/- 2.8) mmHg to 68 (+/- 2.8) mmHg (P < 0.01). It was concluded that epidural anaesthesia may decrease microcirculatory blood flow in free flaps on the lower extremity by diverting flow away from the flap to normal intact tissues (a steal phenomenon).

Evolution of ischemic tissue injury in a random pattern flap: a new mouse model using intravital microscopy.

BACKGROUND: Dissection of random pattern flaps may cause microcirculatory dysfunction and ischemia, which jeopardize wound healing due to impaired tissue viability. The aim of this study was to develop an in vivo model that enables continuous monitoring of the interplay between microcirculatory dysfunction, ischemia, and tissue injury by intravital microscopy. MATERIALS AND METHODS: A laterally based random pattern skin flap (15 x 11 mm) including the panniculus carnosus was raised in the back of mice and fixed into a dorsal skinfold chamber (n = 10). Arteriolar blood flow, functional capillary density, number of apoptotic cells, and area of tissue necrosis were analyzed by intravital fluorescence microscopy in the proximal, middle, and distal part of the flap at day 1, 3, 5, and 7 after surgery. Chamber preparations without flap harvesting served as controls (n = 6). RESULTS: At day 1, the distal part of the flap showed a decreased arteriolar blood flow (266 +/- 124 pl/s versus controls: 1418 +/- 351 pl/s; P < 0.05), which resulted in severe alteration of functional capillary density (43 +/- 11 cm/cm2 versus 270 +/- 7 cm/cm2; P < 0.001). The impaired microcirculation was associated with apoptotic cell death (277 +/- 50 cells/mm2 versus 50 +/- 5 cells/mm2; P < 0.05). Microcirculatory dysfunction persisted over 7 days, and, finally, resulted in 49 +/- 3% flap necrosis. CONCLUSIONS: This new model enables repetitive and simultaneous in vivo microscopic evaluation of microvascular hypoperfusion, apoptosis, and tissue necrosis in a random pattern flap. By the use of gene-targeted mice, it bears great potential to analyze distinct mechanisms of flap failure. It further represents an ideal tool to study novel protective strategies, including induction of angiogenesis, heat shock proteins, and HIF-1alpha.

A dynamic study of the circulation in the gracilis muscle in humans.

The aim of the present study was an evaluation of the relative importance of the proximal and distal pedicles for the perfusion of the gracilis muscle flap, as well as to evaluate the importance of the functional connections between the proximal and distal vascular territories. Ten gracilis muscles were investigated in nine patients. They were all operated on in the supine position under general anesthesia. Microcirculatory blood flow (MBF) in the muscle was measured by a dual-channel laser Doppler flowmeter. Two angled probes were sutured opposite to the entry of the proximal and distal pedicles into the muscle, and were kept in place throughout the measurements. Data were acquired on line via a multichannel interface with acquisition/analysis software to a portable computer. The following measurements were done: during baseline with both pedicles intact; during occlusion of the proximal pedicle; after clamp release; during occlusion of the distal pedicle; after clamp release; after motor-nerve transection; and after disinsertion of the muscle from bone attachments. After clamping the proximal pedicle, MBF decreased proximally to 57 +/- 5 percent (p < 0.01), but remained unchanged distally. After occlusion of the distal pedicle, MBF remained virtually unchanged proximally (92 +/- 4 percent, NS), but decreased to 72 +/- 6 percent (p < 0.05) distally. There was a significantly greater decrease in MBF when the proximal pedicle was clamped, than after clamping the distal pedicle (p < 0.01). There was a strong linear correlation (r = 0.85) between the proximal and distal MBF after occlusion of the corresponding pedicle. Transection of the motor nerve resulted in a moderate increase in MBF values proximally (130 +/- 10 percent, p < 0.05), but not distally (108 +/- 18 percent, NS). Detachment of the muscle led to a distinct increase of MBF in both vascular territories (proximally 175 +/- 28, percent p < 0.05; distally 157 +/- 20 percent, p < 0.05). These measurements demonstrated the dominant role of the proximal pedicle in the gracilis muscle in humans. Furthermore, it was shown that each of the two pedicles (proximal and distal) has its own vascular territory, and that both territories are partially connected by intramuscular vascular anastomoses. The predictable extent of blood flow varies in individual cases and should be measured intraoperatively. In cases of marginal perfusion to the distal part of the muscle, a delay procedure should be considered.