Paul J. Guelinckx

Acral myxoinflammatory fibroblastic sarcoma with unique clonal chromosomal changes

Abstract. Acral myxoinflammatory fibroblastic sarcoma is a rare tumor of the distal extremities. We present the hitherto unreported karyotypic abnormalities of this new entity. The tumor presented as a mass in the dorsum of the foot in a 53-year-old woman and showed the typical virocyte-like and lipoblast-like cells in a myxoid and inflammatory background. Cytogenetic analysis revealed a complex karyotype with a reciprocal translocation t(1;10) (p22;q24) in addition to the loss of chromosomes 3 and 13. Fluorescence in situ hybridization with the 769E11YAC and BAC 31L5 and 2H23 probes showed the breakpoint to be located proximally to BCL10 and distally to GOT1 genes on chromosomes 1p22 and 10q24, respectively. The presence of these clonal chromosomal changes supports the neoplastic nature of acral myxoinflammatory fibroblastic sarcoma and underscores that it represents a separate entity.

Scanning Electron Microscopy of Irradiated Recipient Blood Vessels in Head and Neck Free Flaps

Irradiated and control recipient blood vessels in a similar patient population were studied with scanning electron microscopy. The vessels that were biopsied were then anastomosed to a free flap. Irradiated arteries display a significantly greater wall thickness and higher incidence of intimal dehiscence compared with control arteries. Fibrin deposition, microthrombi, and endothelium cell dehiscence are present more frequently in irradiated vessels than in control vessels. Details of the preparation and anastomotic technique for irradiated blood vessels are discussed. Microvascular surgery in irradiated human blood vessels carries with it a higher risk of thrombosis due to preexisting vessel wall damage. This risk can be minimized by experience and attention to detail.

Muscle transplantation for reconstruction of a smile after facial paralysis past, present, and future

Reconstruction of a natural, spontaneous, symmetrical smile remains the ultimate goal of reanimation of the mid‐face after facial paralysis. Recently the one‐stage mini‐gracilis muscle transplantation, innervated by the contralateral facial nerve, has been introduced to solve this difficult problem. This paper illustrates by means of a historical review the numerous procedures which have led to the development of this intervention. Moreover, it addresses relevant differences between the classical two‐stage procedure using a cross‐facial nerve graft and the recently advocated one‐stage procedure. The underlying neurophysiological mechanism and determination of the final functional outcome of the neurovascular muscle transfer to the face are discussed, and areas which deserve future research are mentioned.

Anal Sphincter Reconstruction with the Gluteus Maximus Muscle: Anatomic and Physiologic Considerations Concerning Conventional and Dynamic Gluteoplasty

Myoplasties have acquired an important place in anal sphincter repair. The use of the gluteus maximus muscle for sphincterplasty was reported initially in 1902. However, in 1952, the gracilis sphincterplasty became more popular because of the accessibility of this muscle. Unfortunately, continence rates, especially after graciloplasty, remained unpredictable because of inability to maintain muscle contraction despite training programs. Training should induce a shift in muscle fiber type distribution toward a more fatigue-resistant composition, with predominance of type I fibers. In order to obtain a more pronounced adaptation in the contractile, histochemical, and metabolic properties of muscle fibers, postoperative intermittent long-term stimulation of the graciloplasty was performed. As these results and the results of dynamic cardiomyoplasty with an implantable myostimulator proved to be successful, implantable pulse generators were used after graciloplasty. Subsequently, continence rates after graciloplasties improved significantly. These data encouraged us to perform dynamic gluteoplasties for anal sphincter repair. This paper presents the results in 7 patients treated by conventional and 4 patients treated by dynamic gluteoplasty. Advantages and disadvantages of gluteoplasty were compared with those of graciloplasty. The neurovascular pedicle of the gluteoplasty underwent less traction after transposition compared with the graciloplasty based on cadaver studies. Gluteus muscle transfer far exceeded the amount of muscle tissue of a normal anal sphincter despite muscle atrophy after transposition. This guaranteed a contractile muscle cuff around the anal canal in contrast to the tendinous sling after graciloplasty. Because of the excellent vascularization of the muscle, microperforations of the rectal mucosa caused by submucosal dissection were sealed, and implantation of electrodes and a pulse generator in one surgical intervention was well tolerated. The myoplasty induced a double curvation of the anal canal in contrast to the graciloplasty, which enhanced the natural anorectal angle. Patient evaluation revealed continence for stool in 9 of the 11 patients; 7 of the 11 patients also were continent for liquids, among them all of the patients who had undergone dynamic gluteoplasties. Mean basal pressure after dynamic gluteoplasty was 49 mmHg, which is lower than the reported mean basal pressure (62 mmHg) during stimulation after dynamic graciloplasty. Squeeze pressure after gluteoplasty, with or without stimulation, proved to be similar to or higher than that obtained in dynamic graciloplasty. Comparing our results of conventional gluteoplasty with the results of graciloplasty prior to stimulation, higher pressures were obtained by the gluteoplasty, especially in squeeze pressures. In the last 5 patients intraoperative pressure measurements were used to restore the optimal resting length of the muscle after transposition. An intraluminal pressure of at least 40 mmHg during rest and 80 to 120 mmHg during stimulation should be obtained to guarantee a future continent sphincter.

Parallel-fibered muscles transplanted with neurovascular repair into bipennate muscle sites in rabbits.

Experiments were performed on 20 New Zealand White male rabbits. Our hypotheses were that (1) latissimus dorsi (LTD) muscles transplanted into the site of a bipennate rectus femoris (RFM) muscle with neurovascular repair would retain their parallel-fibered structure and (2) the parallel-fibered structure of latissimus dorsi grafts would reduce their total fiber cross-sectional area and adversely affect force development relative to that of bipennate rectus femoris grafts and muscles. Compared with their respective donor muscles, 120 to 150 days after grafting, latissimus dorsi and rectus femoris grafts showed no change in the number of fibers and a decrease in the mean single-fiber cross-sectional area to approximately 70 percent. The latissimus dorsi grafts, which remained parallel-fibered, developed maximum forces 34 and 23 percent of the values for fully activated rectus femoris grafts and muscles, respectively. The deficit in the maximum force of the latissimus dorsi grafts resulted primarily from the smaller total-fiber cross-sectional area as a result of the parallel-fibered structure.

Scanning electron microscopic study of microvascular anastomoses on irradiated vessels: Long‐term effect of irradiation

A study was performed to determine the effect of preoperative irradiation on microvascular arterial anastomoses. The study focused on microthrombi and epithelial regeneration. Using scanning electron microscopy (SEM), a clear difference was seen comparing nonirradiated to irradiated vessels. No difference was found between short‐ and long‐term effects of irradiation.

The effect of unilateral partial facial paralysis and muscle ablation on craniofacial growth and development: an experimental study in the rabbit.

&NA; The effect of unilateral partial facial nerve ablation and unilateral partial midface muscle ablation on craniofacial growth and development was investigated. New Zealand White rabbits (12 days old) were randomly assigned to three experimental groups: control group, to study normal craniofacial growth and development (n = 15); nerve ablation group, surgically induced unilateral paralysis of the buccal branches of the facial nerve (n = 15); and muscle ablation group, surgical unilateral ablation of the facial muscles innervated by the buccal branches of the facial nerve (n = 12). All animals were operated on at the age of 12 days; follow‐up evaluations were performed at the ages of 2 months and 6 months. The age of 2 months represents the endpoint of the prepubertal craniofacial growth and development. At the age of 6 months, the animals are fully grown; therefore, the time period between 2 and 6 months is regarded as the pubertal growth period. Computerized dorsoventral roentgencephalometric (measurement of distances and angles) and computer tomographic (threedimensional volumetric measurements) investigations were performed at both ages. Additional dry skull measurements were performed to determine more precisely the bone segments involved in the craniofacial growth alterations studied. The obtained results indicated the following. Unilateral partial facial paralysis involving the midface resulted in growth alterations analogous to those seen after unilateral total facial paralysis. The growth alterations were not to be seen as a growth restriction (reduction in bony volume) but as growth misdirections (alterations in shape). Major growth alterations were present in those regions closely related to the facial musculature, namely the nasal, maxillary, and premaxillary regions, resulting in a snout deviation toward the operated side. The growth alterations occurred during prepuberty and remained rather stable during puberty. Morphologic signs of muscle denervation were related to the craniofacial growth disturbances. The growth alterations after unilateral partial facial paralysis were mainly biomechanically induced, as they were analogous to those observed after unilateral midfacial muscle ablation. The fact that after unilateral midfacial muscle ablation at the age of 6 months the severity of the alterations had increased was attributed to the scar formation inherent to the surgical procedure. (Plast. Reconstr. Surg. 102: 1894, 1998.)

Use of a composite fascial carrier for laryngotracheal reconstruction

A vascularized fascia flap may be used as a vascular carrier for free mucosal and cartilage grafts. This composite reconstruction technique has been performed in clinical situations with complex laryngeal or tracheal defects. This paper describes the technique and the rationale for applying this concept to some particular laryngotracheal defects. Morphologic and histologic aspects of this composite reconstruction technique using a transferable recipient bed are discussed.

Mandibular condylar growth alterations after unilateral partial facial paralysis: an experimental study in the rabbit.

&NA; In a previous study in the rabbit, the authors defined the macroscopic growth alterations after unilateral partial facial paralysis. Dry skull measurements revealed a reduced premaxillary, maxillary, mandibular, and anterior corpus length with a simultaneous increase in mandibular ramal height on the paralyzed side. The authors hypothesize that these mandibular growth alterations are, among others, caused by alterations in condylar growth activity and that an altered occlusal relationship may be involved in the adaptive condylar growth response after facial paralysis. A total of 84 New Zealand White rabbits were used for this study. The animals were randomly assigned to either a control group that was not operated on (n = 28), a group that underwent a sham‐operation (n = 28), or an experimental group (n = 28). In the sham‐operation group, the facial nerve was dissected as in the experimental group but was left intact. In the experimental group, a left‐side partial facial paralysis involving the midfacial muscles was induced by an operation at the age of 12 days. After different follow‐up time intervals of 3.5, 7, 14, 21, 28, 42, and 56 days, four control, four sham‐operation, and four experimental animals (all randomly selected) were killed for histomorphometric measurements of the left control and sham condyles and the left‐side and right‐side experimental condyles. No significant differences between the control and sham‐operation groups were found. The other results revealed that shortly after the paralysis in the experimental group, as compared with the controls, a decrease in condylar growth activity was seen before a catch‐up increase in activity, as expressed by the time‐sequenced decrease and increase in the height of the functional and hypertrophic chondroblast layer. The response on the right side was analogous, though less intense. It is suggested that the mandibular ramal growth alterations might be the result of a chain of adaptations involving the lateral pterygoid muscle and the condylar growth activity. The unilaterally restricted length increment of the maxillary snout, as a result of the loss of tensile forces caused by paralysis of the midfacial musculature, necessitated an adaptation in the position of the mandible to maintain a normal occlusal relationship. Subsequently, the function of muscles involved or influenced by an altered mandibular position, such as the lateral pterygoid muscle, were changed. These altered muscle activities induced condylar growth adaptations, which in turn explained the alterations in mandibular ramal growth.

Perichondrial microvascular free transfer: creation of a compound flap for laryngeal reconstruction in rabbits.

A free revascularized compound perichondrial flap was used over an intralaryngeally placed stent for reconstruction of a frontal laryngeal defect. The microvascular flap replaced the cartilaginous and mucosal defect. Short-term results showed successful reconstruction with a patent airway and viable mucosa. The vascularized sheet of perichondrium was not chosen for its neochondrogenetic effect, but it served as a vascular bed, nourishing the mucous and cartilaginous components in the compound flap. It is suggested that for clinical purposes the reliable fascia forearm flap, which is available in large amounts, can be used as a transferable vascularized bed with a thickness comparable to that of the perichondrial flap.