Free vascularised fibula transplantation for treatment of a fractured femur after radiation therapy.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
P M Werker
Publications and source records attributed to P M Werker.
[Fifty years of plastic surgery in the Netherlands. IX. Reconstructive surgery illustrated by breast reconstruction].
The earliest reports on reconstructive surgery are more than two thousand years old. However, the most significant developments took place in the past four decades. At the beginning of the 21st century we are able to perform reconstructions with a moderate functional and good cosmetic result and limited donor site morbidity. The reconstructive options regarding the mammary region include application of mammary implantation only, and techniques in which autologous tissues are applied, with or without implantations. Autologous tissue is used in transposition of the M. latissimus dorsi, in application of the myocutaneous flap of the M. rectus abdominis ('transverse rectus abdominis myocutaneous flap' (TRAM flap)), which is refined in the 'deep inferior epigastric artery perforator' (DIEP) flap procedure.
Female↗
[Custom-made gold plate prosthesis in the upper eyelid in patients with facial paralysis: improved eyelid closure with less effects on other eye complaints].
OBJECTIVE: To obtain insight into the results of treatment of lagophthalmos by gold weight implantation in the upper eyelid. DESIGN: Retrospective. METHODS: The records of all 37 patients treated in the Netherlands (1986-1998) were reviewed. All traceable patients (n = 33) were sent a questionnaire and invited for clinical evaluation of the treated eye (n = 28). RESULTS: The average follow-up was 44 months (range: 3-150). Twenty-seven patients (82%) reported improved eye closure. After 6 weeks 13 patients (48%) had no eye complaints (dry eye, epiphora, conjunctivitis). At the clinical evaluation 10 patients (36%) had no such complaints. Nine patients (27%) had to undergo a reintervention because of malposition or spontaneous extrusion of the gold weight. It was removed in 4 of them. Upon closure the average residual palpebral aperture was 1.17 mm (range: 0-5) in the patients with gold weight in situ and 6.00 mm (5-10) in the patients in whom the implant had been removed. CONCLUSION: A better eye closure was obtained in 82% of the patients, while eye complaints resolved in 36% of them.
Adolescent↗
Improving the preservation of isolated rat skeletal muscles stored for 16 hours at 4 degrees C.
BACKGROUND: Limiting factors for long-term cold preservation of isolated skeletal muscles are increased intracellular calcium levels, the occurrence of hypercontraction, and the overproduction of oxygen free radicals. In the present study, we investigated whether muscle preservation during cold storage could be improved by additives that can protect against such processes or by oxygen supply. METHODS: The soleus (SOL) and a strip of the cutaneus trunci muscle (CT) from the rat were isolated and stored for 16 hr at 4 degrees C in Bretschneider's Histidine Tryptophane Ketoglutarate (HTK) and subsequently acclimatized in Krebs-Henseleit solution for 90 min at room temperature. The protective effects of 2,3-butanedione monoxime (BDM; reduces intracellular calcium release and inhibits fiber contraction) and of the following antioxidants were investigated: N-tert-butyl-alpha-phenylnitrone (PBN), trolox, desferal, and deferione. The antioxidants and BDM were added to both HTK and Krebs-Henseleit solution. Dose-response curves were made for each of the additives (n> or =4 for each dose). To evaluate the effect of oxygen supply, HTK was aerated with 95% O2/5% CO2. Muscle function (P0), energy metabolism (ATP), and cytoarchitecture were analyzed. The measured values were compared with those of fresh unstored muscles (% of control) and with those of muscles stored in HTK without any additive (multivariate analysis of variance, P<0.05). RESULTS: We found a significant protection of the contractile function (P0) of both muscles after the addition of 1 mM of trolox (SOL: 46% of control; CT: 53%) and after the addition of 3 mM or 0.3 mM of deferione to the SOL and CT, respectively (P0 for both muscles: 55%), whereas no protection was found with PBN (0.03-1 mM) and Desferal (0.001-1 mM). The addition of BDM (10 or 30 mM) resulted in the highest increase of P0 (84% and 60% for the SOL and CT, respectively). The combinations BDM-trolox and BDM-deferione did not further improve the preservation of the SOL function, but P0 values (88% and 91% of control, respectively) were not different from those found for control muscles. Oxygenation of HTK was only beneficial for the SOL (P0: 83%). The improved preservation of muscle function was accompanied by a reduction of the twitch threshold current, increased by storage, suggesting a protective effect of the intervention on the preservation of the muscle cell membrane integrity. Biochemical and histological data corresponded well with the functional data. CONCLUSIONS: The results showed that the addition of BDM and antioxidants (trolox and deferione) to the bathing solutions improved the preservation of the function, metabolism, and cytoarchitecture of isolated skeletal muscles after cold storage for 16 hr.
Animals↗
Effect of vascular freezing on the histopathology of dissected small vessels in the rat: vascular freezing does induce intimal hyperplasia in arteries and veins.
Intimal hyperplasia is the primary response of a vessel wall after injury. It may be the single most significant factor affecting long-term patency. The purpose of this study was to find out whether freeze injury, inflicted on rat microvessels, would be followed by intimal hyperplasia. Toward this aim, we exposed the superficial femoral vessels in the rat. On one side they were frozen using liquid nitrogen spray. The other side was dissected as the control. Vessel segments, harvested immediately and after 1, 2, 3, and 5 months, were studied light microscopically for the occurrence and content of intimal hyperplasia. In the arteries a considerable intimal hyperplasia was found within a 4-week interval, persisting for at least 5 months, as a result of the freeze injury. In the veins, the intimal hyperplasia was much less marked but was nevertheless demonstrable. These findings are not in agreement with earlier studies, in which freezing of injured rat microarteries with liquid nitrogen spray was followed by complete regeneration of the vessel wall, without intimal hyperplasia taking place. The factors contributing to these differences are discussed. It is concluded that freezing of a vessel wall is followed by intimal hyperplasia, which is part of the normal healing process.
Animals↗
Retrospective outcome analysis of staged flexor tendon reconstruction.
Forty staged flexor tendon reconstructions were done in 38 patients between 1991 and 1997. Results were assessed by clinical examination and questionnaire. At follow-up (mean, 35 months) a tenolysis had already been done in 12 cases. In the long fingers there was a significant difference between total active motion (187 degrees ) and total passive motion (237 degrees ). There was also a significant difference between active (24 degrees ) and passive (58 degrees ) IP motion in the thumbs. The mean power grip was 82%, pinch grip 74% and key grip 63% of the contralateral hand. None of the ten FPL reconstructions could be graded as excellent; four were good, using the criteria of Buck-Gramcko et al. (1976). Twenty-eight of the FDP reconstructions had excellent or good results. These results were better than the subjective scores given by the patients, 24 of whom complained of functional problems in daily life at follow-up.
Adolescent↗
Sequential segmental neuromuscular stimulation reduces fatigue and improves perfusion in dynamic graciloplasty.
Dynamic graciloplasty is used as a treatment modality for total urinary incontinence caused by a paralyzed sphincter. A problem with this application is undesirable fatigue of the muscle caused by continuous electrical stimulation. Therefore, the neosphincter must be trained via a rigorous regimen to transform it from a fatigue-prone state to a fatigue-resistant state. To avoid or shorten this training period, the application of sequential segmental neuromuscular stimulation (SSNS) was examined. This form of stimulation proved previously to be highly effective in acutely reducing fatigue caused by electrical stimulation. The contractile function and perfusion of gracilis muscles employed as neosphincters were compared between conventional, single-channel, continuous stimulation, and multichannel sequential stimulation in 8 dogs. The sequentially stimulated neosphincter proved to have an endurance 2.9 times longer (as measured by halftime to fatigue) than continuous stimulation and a better blood perfusion during stimulation (both of which were significant changes, p < 0.05). Clinically, this will not antiquate training of the muscle, but SSNS could reduce the need for long and rigorous training protocols, making dynamic graciloplasty more attractive as a method of treating urinary or fecal incontinence.
Animals↗
Use of the rectus abdominis muscle for abdominal stoma sphincter construction: an anatomical feasibility study.
Permanent fecal abdominal stomas significantly decrease quality of life. Previous attempts to create continent stomas by using dynamic myoplasty procedures have resulted in disappointing outcomes, primarily owing to denervation atrophy of the muscle flap that was used in the creation of the sphincter and because of muscle fatigue resulting from continuous electrical stimulation that is received by the flap to force contraction. On the basis of these problems, we designed two separate studies: an anatomical study addressing flap denervation and a functional study addressing muscle fatigue. The present study addresses the first topic and was designed to develop a rectus abdominis muscle flap into a sphincter that was anatomically situated to create a stoma while preserving as much innervation as possible. In 24 rectus abdominis muscles of human cadavers, the neurovascular anatomy was defined, then the anatomical feasibility of two different muscle flap configurations was considered. The flaps investigated were the peninsula flap and island flap designs, with both using the most caudal segment of the rectus abdominis muscle in construction of the sphincter. Neither flap design required the killing of a nerve for stoma sphincter creation, resulting in minimal muscle denervation. The conclusion of our comparison was that the above, in conjunction with other features of the island flap design, such as muscle overlap after sphincter formation and abdominal wall positioning of the sphincter, made the island flap design better suited to stoma sphincter construction.
Abdomen↗
Sequential segmental neuromuscular stimulation: an effective approach to enhance fatigue resistance.
Electrical stimulation of skeletal muscle flaps is used clinically in applications that require contraction of muscle and force generation at the recipient site, for example, to assist a failing myocardium (cardiomyoplasty) or to reestablish urinary or fecal continence as a neo-sphincter (dynamic graciloplasty). A major problem in these applications (muscle fatigue) results from the nonphysiologic manner in which most of the fibers within the muscle are recruited in a single burst-like contraction. To circumvent this problem, current protocols call for the muscle to be put through a rigorous training regimen to transform it from a fatigue-prone to a fatigue-resistant state. This process takes several weeks during which, aside from becoming fatigue-resistant, the muscle loses power and contraction speed. This study tested the feasibility of electrically stimulating a muscle flap in a more physiologic way; namely, by stimulating different anatomical parts of the muscle sequentially rather than the entire muscle all at once. Sequential segmental neuromuscular stimulation (SSNS) allows parts of the muscle to rest while other parts are contracting. In a paired designed study in dogs (n = 7), the effects of SSNS on muscle fatigability and muscle blood perfusion in gracilis muscles were compared with conventional stimulation: SSNS on one side and whole muscle stimulation on the other. In SSNS, electrodes were implanted in the muscles in such a way that four separate segments of each muscle could be stimulated separately. Then, each segment was stimulated so that part of the muscle was always contracted while part was always resting. This type of stimulation permitted sequential yet continuous force generation. Muscles in both groups maintained an equal amount of continuous force. In SSNS muscles, separate segments were stimulated so that the duty cycle for any one segment was 25, 50, 75, or 100 percent, thus varying the amount of work and rest that any segment experienced at any one time. With duty cycles of 25, 50, and 75 percent, SSNS produced significantly (p < 0.01) enhanced resistance to fatigue. In addition, muscle perfusion was significantly (p < 0.01) increased in these sequentially stimulated muscles compared with the controls receiving whole muscle stimulation. It was concluded that SSNS reduces muscle fatigue and enhances muscle blood flow during stimulation. These findings suggest that using SSNS in clinical myoplasty procedures could obviate the need for prolonged training protocols and minimize problems associated with muscle training.
Animals↗
[Free muscle transplantation after complex fractures of the lower leg and ankle: results from 32 patients].
OBJECTIVE: To describe the results of free vascularized muscle transfer for treatment of complications of severe open fractures of the distal tibia and ankle region. DESIGN: Retrospective. METHODS: In 1994-1998, 32 patients underwent free muscle transfer for soft tissue reconstruction after high energy injury to the distal tibia and ankle region. In six patients reconstruction took place within one week after the injury (group 1); 13 patients underwent free muscle transfer in combination with (re)osteosynthesis and cancellous bone grafting for treatment of infected (defect) pseudarthrosis (group 2); chronic posttraumatic osteitis existed for an average of 12 years in six patients (group 3); in seven patients the indication was determined by unstable scar tissue, cosmetic reasons, or as preparation for corrective osteotomy (group 4). RESULTS: Three haematomas and two thrombembolic complications were encountered. Amputation could not be avoided in three patients. Consolidation of the fracture, pseudarthrosis or arthrodesis and/or eradication of infection was accomplished in all remaining 29 patients. An average of 2.2 (range: 0-7) reinterventions were additionally needed in groups 1-3, including reosteosynthesis, sequestrectomy, cancellous bone grafting and/or arthrodesis. CONCLUSION: In case of severe open fracture of the distal tibia and/or ankle region, free vascularized muscle transfer provided cover of the fracture or pseudarthrosis region, thereby improving local vascularisation. This treatment protects the underlying bone, enhances osteogenesis and improves resistance to infection.
Adult↗
Microcirculatory changes following different temperature washouts in a free flap model.
In spite of the extensive experimental work on vascular washout in free flap surgery, an optimal temperature for the washout solution has not been established. This study was designed to determine the effect of the washout solution temperature on the degree to which the microcirculation is cleared of blood. The cremaster muscle flap in the rat was used, in which the microcirculation can be directly viewed and the presence of blood and perfusion parameters within various vessels can be measured during and after washout. Washout was started with a single, high-pressure infusion and continued at 130 mmHg for 15 minutes. The temperature of the washout solution was either 2-3, 20-22, or 35 degrees C. In all three groups, washout cleared the microcirculation almost completely within the first minute. However, we observed that a cold or room temperature washout cleared the microcirculation more completely than a warm washout did. The temperature of the washout solution did not effect post washout capillary perfusion and/or arterial diameters.
Animals↗
Contractile properties of rat skeletal muscles following storage at 4 degrees C.
The purpose of this study was to assess the potential of preservation solutions for protecting skeletal muscle function during storage at 4 degrees C. The soleus and the cutaneus trunci (CT) from the rat were stored for 2, 8 or 16 h at 4 degrees C in University of Wisconsin solution (UW), HTK-Bretschneider solution (HTK) or Krebs-Henseleit solution (KH). After storage, muscles were stimulated electrically to analyse the isometric contractile properties, such as the maximum tetanic tension (P(0)). Histological analysis was also performed. In separate experiments, the effect of the diffusion distance on muscle preservation was studied by bisecting the soleus. After 8 h of storage in UW or HTK, the contractile properties of the CT were similar to those of the control, whereas those of the soleus were reduced (P(0) values of 16% and 69% of control in UW and HTK respectively). At 16 h, the contractile properties of the CT (P(O) 28%) were again better preserved than those of the soleus (P(0) 9%). Muscle function deteriorated most after storage in KH (P(0) at 16 h: soleus, 3%; CT, 17%). The bisected soleus was equally well preserved as the CT (P(O) of bisected soleus at 8 h in UW and HTK: 86%). The functional data corresponded well with the histological data, which showed increasing muscle fibre derangement with increasing storage time. For both muscles and all solutions, the threshold stimulus current increased with increasing storage time (control, 0.1 mA; 16 h, 1.2 mA) and was strongly correlated with the deterioration in contractile properties. It is concluded that, at 4 degrees C, muscle is preserved better in UW and HTK (intracellular-like solutions) than in KH (extracellular-like solution). The soleus and CT were best protected in HTK. The diffusion distance is a critical factor for successful preservation of muscle function at 4 degrees C. The reduced function after 16 h of storage at 4 degrees C was caused by hypercontraction and necrosis of about 25% of the muscle fibres, and by deterioration of the electrical component of excitation-contraction coupling of the remaining fibres.
Animals↗
Three parameters optimizing closed-loop control in sequential segmental neuromuscular stimulation.
In conventional dynamic myoplasties, the force generation is poorly controlled. This causes unnecessary fatigue of the transposed/transplanted electrically stimulated muscles and causes damage to the involved tissues. We introduced sequential segmental neuromuscular stimulation (SSNS) to reduce muscle fatigue by allowing part of the muscle to rest periodically while the other parts work. Despite this improvement, we hypothesize that fatigue could be further reduced in some applications of dynamic myoplasty if the muscles were made to contract according to need. The first necessary step is to gain appropriate control over the contractile activity of the dynamic myoplasty. Therefore, closed-loop control was tested on a sequentially stimulated neosphincter to strive for the best possible control over the amount of generated pressure. A selection of parameters was validated for optimizing control. We concluded that the frequency of corrections, the threshold for corrections, and the transition time are meaningful parameters in the controlling algorithm of the closed-loop control in a sequentially stimulated myoplasty.
Algorithms↗
Muscular urinary sphincter: electrically stimulated myoplasty for functional sphincter reconstruction.
PURPOSE: To reconstruct an electrically stimulated muscular urinary sphincter (MUS) using a tailored gracilis muscle free flap with intact nerve. MATERIALS AND METHODS: Unilateral surgically tailored gracilis muscle free flaps were transferred into the pelvis in eight dogs, leaving the obturator nerve intact. The muscle's pedicle vessels were anastomosed to the inferior epigastric artery and vein in the pelvis and the muscle was wrapped around the bladder neck. Electrodes were inserted into the MUS and connected to a programmable pulse generator. After 8 weeks of training the MUS, the pulse generator was programmed to be "on" for 4 hours and "off' for 15 minutes in a continuous cycle. Urodynamic studies were performed periodically, and at the end of the experiment the MUS and proximal urethra were harvested for histology. Three control dogs had sham operations. RESULTS: All MUS's functioned well following the procedure. Histology of the MUS/urethra complex showed no evidence of stricture. Except for one dog, all urethras were easily catheterized. CONCLUSIONS: This electrically stimulated innervated free-flap MUS technique effectively increases bladder outlet resistance without producing urethral obstruction.
Animals↗
Function of rat skeletal muscles after storage at 10 degrees C in various preservation solutions.
1. The purpose of this study was to assess the potential of various preservation solutions, orginally designed for solid organs, to protect muscle function during cold storage. 2. The soleus (SOL) and the cutaneous trunci (CT) muscle from the rat were isolated and stored for 2, 4 or 8 h at 10 degrees C. The solutions used, listed in order from an intracellular to an extracellular-like composition, were: University of Wisconsin (UW), Euro-Collins (EC), HTK-Bretschneider (HTK), reversed St. Thomas' Hospital (ST2) and Krebs-Henseleit (KH). After cold storage, the muscles were tested by direct electrical stimulation to obtain the maximum twitch tension (Pt) and the maximum tetanus tension (P0). Subsequently, the muscles were prepared for morphological analysis. 3. In general, storage at 10 degrees C caused a gradual decrease of Pt and P0 with time. After 8 h of storage in the extracellular-like solutions KH and ST2, the P0 was about 50% (SOL) and 35% (CT) of control. Eight hours of storage in intracellular-like solutions resulted in a P0 of 50% of control for HTK, in a P0 of 40% (SOL) and 67% (CT) for UW, but in a P0 of 5% (SOL) and 26% (CT) for EC. These findings corresponded well with the morphological observations. 4. It is concluded that the effects of 10 degrees C storage on skeletal muscle function are not predominantly determined by the intra- or extracellular-like composition of the solutions used. Both UW and HTK were most effective (P0 > 50% of control) in preserving muscle function.
Animals↗
Electrically stimulated free-flap graciloplasty for urinary sphincter reconstruction: a new surgical procedure.
In electrically stimulated (dynamic) graciloplasty for urinary incontinence, the gracilis muscle is transposed into the pelvis, and the distal part is used to reconstruct a neosphincter. Clinical outcomes using this technique have been disappointing due to stricture of the urethra caused by ischemia in the distal part of the gracilis and limited gracilis length available for neosphincter construction. Furthermore, the urethra is twisted by the contracting gracilis, rather than circumferentially squeezed. The purpose of the present study was to test the anatomical and functional feasibility of a new surgical approach to reconstruct a urinary sphincter, using the gracilis muscle as a free flap. In 12 human cadavers, the anatomical feasibility for creating a neosphincter by using the gracilis free flap was determined. In all cases, transfer of the gracilis muscle into the pelvis as a free flap (with the nerve intact) was feasible, and ample muscle was available to construct a neosphincter around the bladder neck. Gracilis neosphincter function was studied in seven dogs. The left gracilis muscle was subjected to transfer into the pelvis as an innervated free flap to create a neosphincter around the urethra. The right (control) gracilis muscle was lifted as a single pedicle flap, remained in situ, and was wrapped around a stent to mimic the urethra. Function (expressed as peak pressure generation and fatigue rate) and surface perfusion were determined for all gracilis muscles. In each dog, both sides were compared using the paired Student's t test for statistical analysis, and no significant difference was measured for the two groups. In conclusion, an innervated gracilis free flap can be used to create a neosphincter around the bladder neck. In an acute study in dogs, function and perfusion of the innervated gracilis free flap are not compromised.
Animals↗
The prepuce free flap: dissection feasibility study and clinical application of a super-thin new flap.
The aim of this study was to develop a free flap of the male prepuce. First, a dissection feasibility study was performed in eight male cadavers. Dissection proved feasible, and the mean surface area of the prepuce, when folded out, was 46.7 cm2. The mean pedicle length was 15 cm, with a mean diameter of the inferior external pudendal artery at its origin of 1.2 mm and a mean diameter of the inferior external pudendal vein at its origin of 1.9 mm. Next, a viability study was performed by isolating a prepuce free flap during male-to-female sex reassignment procedures. The flap as well as the residual skin of the penis shaft remained well perfused. Thereafter, the new prepuce free flap was successfully applied for the reconstruction of defects of the floor of the mouth, tongue, and oropharynx in two patients. The thinness and pliability of the flap, its large surface area, the long vascular pedicle, and the limited donor-site morbidity are the major advantages of this new flap. The possibility to raise the flap simultaneously with the tumor resection is an additional advantage. The small caliber of the flap artery seems to be the only drawback.
Aged↗
Review of facilitated approaches to vascular anastomosis surgery.
BACKGROUND: There is an increasing demand for an easier, quicker, less damaging, but reliable procedure to create a vascular anastomosis. This demand is not new but is revitalized by the movement of vascular procedures in various specialties, including cardiac surgery, toward minimally invasive procedures. This article reviews the most important representatives of devices or methods that have been developed in the last two centuries. METHODS: A thorough literature search was performed. The outcome is presented and discussed in four parts: (1) stapling and clipping devices, (2) coupling devices, (3) glues, and (4) laser welding. RESULTS: Stapling devices have not become the standard fashion to create an anastomosis because they are too complicated to use. In selected cases clips have potential in vascular surgery. There is a ring-pin coupling system available that is easy to use and especially suitable for creating an end-to-end anastomosis. The ideal glue is yet to be developed, and the currently available laser welding techniques have to become refined. CONCLUSIONS: It is anticipated that the future lies in hybrid techniques that combine sutures or clips with glues or laser-welding techniques.
Anastomosis, Surgical↗