Virtual reality techniques in reconstructive surgery.
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Bone Transplantation↗
Biomedical subjects
W D Boeckx
Publications and source records attributed to W D Boeckx.
Horseshoe expanded scapular free flap shows no venous congestion.
The free scapular flap is a reliable solution when a relatively thin cutaneous flap is required, but its dimensions limit its use in large defects. The pre-transfer expansion of the flap has extended its clinical applications, but problems still occur. Distal marginal venous congestion and subsequent partial necrosis of the flap can occur during the conventional round-shaped expansion of the flap. Here, we present a new pattern of flap pre-expansion: the 'horseshoe'-shaped expansion. The main indications for this procedure and the surgical details are described. Advantages and disadvantages over the conventional expanded free scapular flap are discussed.
Adolescent↗
Scanning electron microscopic analysis of the stapled microvascular anastomosis in the rabbit.
BACKGROUND: Despite the high percentages of experimental and clinical patency rates achieved using so-called mechanical anastomotic devices (Unilink; 3M, St. Paul, MN; vascular staples) they remain little known and occasionally used. METHODS: The VCS Auto Suture microstapler technique for microvascular anastomosis was tested experimentally and compared with the conventional "gold standard" 10/0 end-to-end microvascular technique. Thirty carotid arteries on one side of 30 rabbits were stapled using nonpenetrating 0.9-mm (small) VCS Auto Suture microclips, and the other 30 carotid arteries on the other side were sutured in a conventional way with 10/0 monofilament nylon. A 100% patency rate was achieved on both sides. Biopsy was performed in five groups of rabbits at different time intervals postoperatively, and the specimens were examined under scanning electron microscopy. RESULTS: All 60 anastomoses were patent. Histomorphologic examination of the anastomotic site revealed no major differences between sutured and stapled groups. CONCLUSIONS: Stapled microvascular anastomosis technique is fast and reliable.
Anastomosis, Surgical↗
The fate of the oblique abdominal muscles after free TRAM flap surgery.
During recent years, clinical research on the donor site morbidity after free or pedicled transverse rectus abdominis myocutaneous (TRAM) flap surgery has been focusing on the reduced flexion capacity of the abdominal wall. However, the rectus abdominis muscles have close interactions with their synergists and antagonists and collaborate with their neighbouring muscles. The purpose of this study was to examine the consequences of partially resecting the rectus abdominis muscle on the different muscle groups of the abdominal wall. Twenty free TRAM flap patients, 12-61 months (mean 32.1 months) after surgery, were clinically examined, evaluated for curl-up performance and underwent isokinetic dynamometry for flexion, extension and rotation. The patients were compared with 20 non-operated controls. Nineteen patients answered a questionnaire. Abdominal wall abnormalities occurred in 10 patients: umbilical asymmetry (n = 3), abdominal wall asymmetry (n = 4), lower abdominal bulging (n = 2) and hernia (n = 1). Curl-up performance was less in the TRAM flap patients (P = 0.001, Mann-Whitney). Isokinetic flexion, extension and rotation were also less in the TRAM flap patients (Fisher's exact test). This study indicates that what has been believed to be 'limited' surgical damage to the abdominal wall leads to an important reduction in flexion strength but to an even more important reduction of rotation strength due to bilateral displacement and damage of the insertion of the oblique muscles. Partial compensation by synergists is variable and unpredictable on an individual basis. These functional disorders can potentially lead to important changes in activities of daily life.
Abdominal Muscles↗
The donor site morbidity of free DIEP flaps and free TRAM flaps for breast reconstruction.
This study was undertaken to demonstrate that the deep inferior epigastric perforator (DIEP) flap can provide the well-known advantages of autologous breast reconstruction with lower abdominal tissue while avoiding the abdominal wall complications of the transverse rectus abdominis myocutaneous (TRAM) flap. Eighteen unilateral free DIEP flap breast reconstruction patients were assessed 12-30 months (mean 17.8 months) after surgery. Clinical examination, physical exercises and isokinetic dynamometry were performed preoperatively and two months and one year postoperatively. Intraoperative segmental nerve stimulation, visual evaluation and postoperative CT scans were also used to quantify the damage to the rectus muscle. The 18 patients were then compared with 20 free TRAM flap patients and 20 non-operated controls. Two DIEP flap patients presented with abdominal asymmetry. A limited decrease of trunk flexing strength was noticed but rotatory function was intact. Ten of the TRAM flap patients had umbilical or abdominal asymmetry, bulging or hernias. TRAM flap patients showed a statistically significant reduction in strength to flex and to rotate the upper trunk compared to both the one year postoperative DIEP flap group and the control group. The answers to a questionnaire revealed impairment of activities of daily living for some TRAM flap patients while the activities of all DIEP flap patients were unaffected. Our data demonstrate that the free DIEP flap can limit the surgical damage to the rectus abdominis and oblique muscles to an absolute minimum. We believe it is worthwhile to spend extra operative time, the main disadvantage of this technique, to limit late postoperative weakness of the lower abdominal wall.
Abdominal Muscles↗
Refinements in free flap breast reconstruction: the free bilateral deep inferior epigastric perforator flap anastomosed to the internal mammary artery.
Besides the enormous advantages of reconstructing the amputated breast by means of a conventional TRAM flap, the main disadvantage remains the elevation of small (free TRAM) or larger (pedicled TRAM) parts of the rectus abdominis muscle. In order to overcome this disadvantage, the free Deep Inferior Epigastric Perforator (DIEP) skin flap has recently been used for breast mound reconstruction with excellent clinical results. After achieving favorable results with eight unilateral DIEP-flaps, we were challenged by an abdomen with a midline laparotomy scar. By dissecting a bilateral DIEP flap and making adjacent anastomoses to the internal mammary artery we were able to achieve sufficient flap mobility for easy free flap positioning and breast shaping. Intraoperative segmental nerve stimulation, postoperative functional abdominal wall tests and CT-scan examination showed normal abdominal muscle activity. On the basis of a case report, the technical considerations and advantages of anastomosing the bipedicled DIEP flap to the internal mammary artery are discussed.
Adult↗
Scanning electron microscopic study of thrombus formation in an end-to-side anastomosis of the rat carotid artery.
The healing of conventional microvascular end-to-side anastomoses has been reported in several studies. The authors studied thrombus formation under scanning electron microscopy (SEM) in an end-to-side anastomotic model in rat carotid arteries. Twenty anastomoses were carried out with 10-0 nylon interrupted sutures. Thrombus formation was evaluated 30 min after clamp release. The findings indicated that the first 30 min are the most critical time for thrombus formation. Thrombi underwent partial lysis or embolization after this time, and gross intraluminal thrombi did not recur. Thrombus formation was studied at four different sites in the end-to-side anastomoses. The sites of needle holes and sutures were primary locations for thrombocyte adhesions and aggregations in normal, vascular anastomoses.
Anastomosis, Surgical↗
Experimental transferable vascular bed for laryngotracheal reconstruction: further observations.
Free fascia flaps have proven most reliable in providing a vascular bed for an epithelial free graft without adding bulk. They may be a useful tool for laryngotracheal reconstruction. A free flap consisting of a vascular network running in connective tissue can be developed on the rabbit external ear. The vascular characteristics of this flap were examined to test the reliability of the transferable vascular bed in laryngotracheal repair. The perichondrial free flap is useful for bringing an internal lining inside the lumen and for circumferential protection of supporting tissue. However, the natural tendency for surface contraction of perichondrium is a major disadvantage.
Animals↗
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.
Animals↗
Possibilities in hypopharyngeal reconstruction--comparative study.
A comparative study between three types of hypopharyngeal reconstruction after laryngopharyngectomy is presented by evaluation of the following parameters: complications, duration of hospitalization and postoperative swallowing time. Each group contains the five most recently cases treated at the E.N.T. department of the K.U. Leuven. In recent years, the following types of hypopharyngeal reconstruction were used: the pectoralis major flap, the free radial forearm flap and the revascularized jejunum interposition. For reconstruction of circumferential hypopharyngeal defects after total laryngopharyngectomy, the jejunal graft presents hopeful results.
Forearm↗
Hypopharyngeal stenosis and fistulas. Use of the radial forearm flap.
The radial forearm flap is a thin, pliable, and well-vascularized fasciocutaneous flap. The forearm flap is, in selected cases, along with the pediculated regional and distant musculocutaneous flaps, a versatile method for pharyngeal reconstruction. We describe the use of the flap in nine clinical cases of hypopharyngeal stenosis and fistulas. The advantages of this method for hypopharyngeal reconstruction are presented.
Adult↗
Early ovum and embryo loss after microsurgical anastomosis of the rabbit oviduct.
After resection and reanastomosis, ovum recovery and fertilization were studied in the rabbit oviduct. From these data the ovum and embryo loss was calculated. Loss was most pronounced in ampullary operated tubes and after a short recovery period.
Anastomosis, Surgical↗
Ovum recovery after microsurgical reanastomosis of the rabbit oviduct.
Causes for failure of pregnancy after tubal reconstructive surgery are incompletely understood. The impact of microsurgical resection reanastomosis on ovum recovery was studied in the rabbit oviduct. One hundred sixty rabbits were divided into three groups: one experimental group in which a resection reanastomosis was made in the ampullar or isthmic tubal segment, respectively, and two control groups. After mating, ovum recovery was evaluated. In ampullary operated oviducts the ovum recovery rate was significantly lower compared with recovery rates in isthmically operated and in control oviducts. Furthermore, in ampullary operated oviducts peritoneal transmigration of ova was frequently observed. Disturbances in ovum pickup from the ovarian surface or the peritoneal cavity seem to be responsible for the decrease in recovery rate found in the ampullary operated oviducts.
Animals↗
Ovum transport after microsurgical anastomosis of the rabbit oviduct.
From experimental work in rabbits it is known that pregnancy outcome is influenced unfavorably by tubal resection anastomosis in spite of the preservation of tubal patency. In 104 Dutch belted rabbits the impact of microsurgical resection anastomoses on ovum transport during the first 24 hours after ovulation was examined. In oviducts in which the ampulla had been operated on, ovum transport was delayed. Mucosal irregularities that interfere with normal ampullary transport by cilia activity may account for the delay noted. Alterations in the duration of ovum transport in the oviduct may influence pregnancy outcome by creating an inappropriate tubal environment for the early embryo or by creating asynchrony between the embryo and the endometrium. No changes were observed in transport in oviducts in which the isthmus had been operated on: even a small segment of isthmus seems to act as a physiologic sphincter and to prevent premature ovum entrance into the uterus.
Animals↗
Nerve fiber planimetry in acute and chronic nerve lesions and in nerve lesions in continuity.
The level of resection of damaged nerve tissue in acute and chronic nerve lesions was determined on the basis of the vascular structure, the consistency of the nerve during palpation, the amount of interfascicular connective tissue, and the mushroom formation of the fascicles. Intraoperative electrophysiologic recordings were performed on the cut nerve ends to determine the function of the axons. Postoperative planimetric analyses of cross sections made through the resected nerve stumps were performed to measure axonal and endoneural tube diameters and to correlate these results with the clinical criteria used through the operating microscope. Axons in the proximal nerve ends of acute and chronic nerve lesions displayed a similar mean diameter. Endoneural tubes in chronic nerve lesions shrunk significantly as nerve repair was delayed. In several nerve lesions in continuity, axons remained present across the injured site despite absence of electrical conduction. When comparing the results of axonal or endoneural tube diameters of chronic nerve lesions to the results of other studies or acute nerve lesions, we demonstrated that careful examination through the operating microscope provided valid information about the proper management and resection level of chronic nerve lesions. Electrophysiologic evaluation aided the surgical management but was not useful for the resection of the distal damaged nerve segment. The presence of an evoked potential in the proximal nerve ends guaranteed a nearly normal nerve fiber diameter distribution, while the absence of such a potential in the distal nerve ends indicated an abnormal, absent, or disturbed endoneural tube diameter histogram.
Acute Disease↗
Rectus femoris muscle grafts performed with and without vascular anastomosis: an experimental study in the rabbit.
To study the effect of vascular repair on muscle transplants, rectus femoris muscles in rabbits were grafted orthotopically with and without microsurgical blood vessel repair. The function and structure of the grafts were evaluated 90 days after operation. Contractile properties were measured in vivo. Muscle biopsies were stained for nerve and motor end-plate regeneration. The twitch tension and maximal tetanic tension returned respectively to 32 +/- 6% and 32 +/- 7% of control values in the vascular transplants. In the avascular transplants twitch tension and maximal tetanic tension were respectively 6 +/- 1% and 8 +/- 1% of control values. Poor regeneration of muscle fibres, infection, fibrosis and immature reinnervation were the reasons for failure of avascular transplants. The avascular muscle grafts had insufficient contractile properties and were more static than dynamic. In conclusion, large avascular muscle grafts should be avoided because of the likelihood of poor revascularisation with extensive ischaemic necrosis, resulting in scar tissue.
Animals↗
Experimental hydrosalpinx and salpingostomy in rabbits.
In 137 oviducts of New Zealand white rabbits different kinds of occlusion techniques were tested to induce hydrosalpinges. In 99 oviducts ligatured or clipped both at the fimbrial end and at the ampullary-isthmic junction 67 hydrosalpinges were achieved, whilst in 34 oviducts ligatured or clipped only at the fimbrial end one hydrosalpinx occurred. Most severe histological changes were seen after double clipping. Ligation of the blood vessels to and from the ampulla of 4 oviducts caused no hydrosalpinx formation. After cuff salpingostomy a higher number of patent oviducts was found than after double-loop salpingostomy.
Animals↗
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.
Arteries↗