Search PubMed⌕ Search

Biomedical subjects

J Holle

Publications and source records attributed to J Holle.

At least 37 records · Page 2Linked to original sources
PubMed1997

[Present status and future aspects of the respiratory pacemaker].

Under certain conditions, phrenic pacing is a rare but most effective and attractive alternative for long-term ventilation. General indications concern diseases of the breathing center, for example Undine's disease (loss of CO2 sensitivity) in infants and high cervical spinal cord lesions in the level of C0 to C3. Despite of the advantage of physiologic respiration mode (no positive air pressure) compared to long-term ventilation, the phrenic pacemaker enables high life quality for the patients due to possibilities of closing of tracheostoma (Vienna system), an optimum in mobility and high cost effectiveness. International research and development in this area concerns 1. nerve transposition of an innervated nerve to a denervating phrenic nerve, 2. additional stimulation of thoracal muscles for inspiration, 3. additional stimulation of expiration, 4. endoscopic operative positioning of the electrodes, 5. development of a pacer with sensor input for an individual respiration rhythm (controlled by the vocal cord) and 6. development of a fully implantable system Improvements of the present pacemaker system may lead to enlargement of indications, for example use in patients with severe nocturnal arrhythmias in respiration.

Adult↗
PubMed1997

The external oblique muscle free flap.

To date, the external oblique muscle has been considered to have a purely segmental vascular supply and therefore has been used surgically only as a pedicled flap. To better define the vascular anatomy and nerve supply of the muscle, we performed arterial injection studies and dissected the nerves that entered the muscle in 35 human cadavers. We found that in addition to the segmental arteries, one or two large branches of the deep circumflex iliac artery contributed significantly to the blood supply of the external oblique muscle in 33 of the 35 cadavers. We also found that the lateral cutaneous branches of the intercostal nerves entered and supplied the muscle near its origin from the rib in a strictly segmental pattern. These anatomic findings enabled us to transplant the external oblique muscle successfully as a free flap based on the deep circumflex iliac vessels in six patients. The muscle flap is thin, pliable, and can be combined with an iliac bone or an abdominal skin transplant. Its vascular pedicle is long (mean 12 cm) and of adequate diameter for microvascular repair. The donor scar of the flap is inconspicuously situated along the inguinal ligament and the iliac crest. Finally, since the muscle has a multiple nerve supply, it has the potential to provide several functional units at the recipient site when transplanted as a functional free flap.

Abdominal Muscles↗
PubMed1997

Scarpa's fascia flap: anatomic studies and clinical application.

Fascia and fascia-subcutaneous flaps are thin, pliable, and well-vascularized tissue with aesthetic and functional advantages, particularly for the extremities and in the head and neck region. Although various donor sites have been used for these flaps, there is an occurrence of unsatisfactory donor-site defects that are often complicated by conspicuous, widened scars or alopecia. In addition, flap elevation is sometimes prolonged because of the demanding operative procedures as well as the impossibility of a two-team approach. In this anatomic and clinical study we present a new fascial flap that results in a minimal donor-site defect and a short and easy operative procedure. Scarpa's fascia, which can be used as both a free and a pedicled flap, is a well-defined single membranous sheet within the subcutaneous tissue layer at the lower abdominal wall. We studied its distribution, structure, and vascular supply in 27 fresh cadaver specimens. In addition, computed tomographic (CT) and ultrasound studies were performed in 13 healthy volunteers and in 3 cadavers before and after injection of diluted contrast material in the superficial epigastric artery. Finally, histologic examinations were done with hematoxylin and eosin or with reticulum and elastin. Our studies showed that Scarpa's fascia provides a thin, pliable, and well-vascularized flap pedicled on the superficial epigastric artery. After successful application of the Scarpa's fascia flap as a free flap in 3 patients and as a pedicled option in 1 patient, we can recommend this flap as a valuable tool for the reconstructive surgeon.

Abdominal Muscles↗
PubMed1997

The vertically based deep fascia turnover flap of the leg: anatomic studies and clinical applications.

Although fasciocutaneous turnover flaps are a simple and fast method for covering soft-tissue defects of the lower leg, many reconstructive surgeons have their doubts about them. They revolve around the lack of criteria for safely designing these random-pattern flaps and around the risk of donor site problems. A vertically based deep fascia turnover flap with a paratibial or parafibular pedicle is presented. Anatomic studies of 36 injected lower limbs showed the deep fascia to be supplied by a mean of 61 vessels. As musculofascial, septofascial, and periosteofascial branches, these contribute to a richly anastomosing vascular network within the deep fascia. Along the deep transverse septum at the medial tibial border, the anterior and posterior peroneal septa, and between the anterior tibial and extensor muscles, the fascia is supplied by segmental vessels in a clearly defined arrangement. Pedicled on these vessels, the deep fascia is a useful candidate tissue for transversely oriented turnover flaps. These are particularly well suited for covering pretibial or prefibular soft-tissue defects. Unlike adipofascial turnover flaps, the transversely oriented deep fascia turnover flap keeps its subcutaneous layer with its intact vascular plexus so that the overlying skin is adequately perfused even in patients with sizable flaps or an extremely thin skin. Clinical experience with the vertically based paratibial or parafibular deep fascia turnover flap in six patients confirmed its usefulness for covering small to medium-sized soft tissue defects of the lower leg.

Adult↗
PubMed1997

[Tissue preparation in combined scapula flap for microsurgical reconstruction of defects of the oromaxillofacial area].

Nowadays, in congenital or acquired large oro-maxillofacial defects microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aim of reconstruction includes not only restoration of stable continuity and esthetic contour, but also the restoration of a functioning "chewing organ". For reconstruction in maxillary and midface defects, we prefer the scapular flap for a single-step reconstruction. Tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable soft tissue conditions at the time of microsurgical reconstruction. Following dental restoration, full oral function is given. This single-stage procedure improves the psychosocial situation of the patient considerably when compared with conventional multi-stage reconstruction.

Adult↗
PubMed1996

Effect of the CO2 milliwatt laser on neuroma formation in rats.

BACKGROUND AND OBJECTIVE: The purpose of this study was to determine whether the milliwatt laser can suppress neuroma formation at the end of a divided nerve. STUDY DESIGN/MATERIALS AND METHODS: The peripheral nerves of eight rats were transected with microscissors and the cross-sectional area of their proximal ends was irradiated using the CO2 milliwatt laser. The power ranges used were similar to those applied to weld neural tissue. RESULTS: None of the eight irradiated nerve ends formed a neuromatous bulb and only one of them regenerated into the surrounding tissues. Histologically, these nerve ends did not show the disorganized picture of classic neuromas. On morphometric measurements, they contained less connective tissue than the control nerve ends (P < 0.001) and their nerve fibers were larger in diameter (P < 0.001) and better myelinated (P < 0.001). CONCLUSION: These findings in rats show that the CO2 milliwatt laser has the ability to suppress neuroma formation at the end of a divided nerve.

Animals↗
PubMed1996

Endoscopic carpal tunnel release using a single-portal system.

In this prospective clinical study, we present our experience with a new single portal carpal tunnel release kit. The safety and efficacy of this new device was assessed and compared with a consecutive control group treated with conventional open carpal tunnel release. 126 patients were enrolled in this study, 64 of them were treated endoscopically (group 1) and 62 by open release of the carpal ligament (group 2). Follow-ups were conducted at 1, 3, 6, 12 and 24 weeks postoperatively. A serious intraoperative complication in group 1 was a transection injury of a branch of the superficial palmar arch. No intraoperative complications were noted in group 2. Postoperative evaluation revealed significantly less scar tenderness in group 1 at 1 week (P < 0.001), 3 weeks (P < 0.001) and 24 weeks (P < 0.05) compared to group 2. Functional status at 1 week was significantly (P < 0.05) better in group 1 than in group 2 but not at later times. Grip strength at 1 week (P < 0.001), 3 weeks (P < 0.05) and 12 weeks (P < 0.05), and pinch strength at 3 weeks (P < 0.001) were significantly higher in group 1. No significant differences between the groups were obtained regarding postoperative symptom severity. The new device provides a reliable tool for single portal carpal tunnel release, although the risk of inadvertent damage to the neurovascular structures always remains a possibility with the endoscopic carpal tunnel technique.

Activities of Daily Living↗
PubMed1996

Prefabrication of combined scapula flaps for microsurgical reconstruction in oro-maxillofacial defects: a new method.

Nowadays, in congenital or acquired large oro-maxillofacial defects, microsurgical reconstruction is mainly performed by revascularized osseous, osteocutaneous, or osteomyocutaneous distant flaps. The aims of reconstruction include not only restoration of stability and aesthetic contour, but also the restoration of a functioning 'chewing organ'. In addition to bulkiness of the flaps, the stepwise surgical procedure (microvascular reconstruction, osseointegration of implants, secondary correction of flaps including preprosthetic surgery, etc.) prevents physiological oral function for a long time, and has some implications for creating an alternative method of microsurgical reconstruction with newly designed flaps. For reconstruction in maxillary and midface defects we prefer the use of the scapula flap. Since modern diagnostic methods allow comprehensive planning and defining of all relevant anatomical and functional factors in advance, the 'simultaneous' microvascular reconstruction by prefabricated scapula flaps has become possible and offers some advantages. The tissue prefabrication results in osseointegrated implants and thin mucosal linings with stable peri-implant soft tissue conditions at the time of microsurgical reconstruction. Postoperatively, after immediate dental restoration full oral function is attained. The 'simultaneous' reconstruction improves the psychosocial situation of the patient considerably.

Adult↗
PubMed1996

Vienna phrenic pacemaker--experience with diaphragm pacing in children.

Eight children, five boys and three girls, aging from 2 to 13 years (M = 9 +/- 3) were treated with the "Vienna phrenic pacemaker". Indication for implantation was central alveolar hypoventilation syndrome (CAH) in one case and total ventilatory insufficiency due to high cervical cord or brain stem lesion (SCI) in seven cases. Four electrodes were applied to each phrenic nerve via sternotomy. Both hemidiaphragms were paced synchronously with increasing duty cycles to condition the diaphragms for continuous electrophrenic respiration (EPR). EPR could be performed successfully in all children but one. Four children could achieve chronical EPR, one is in conditioning period. Two patients could not be discharged from hospital due to parental neglect and died after two and three years of intermittent stimulation. Six children could be discharged from hospital, two of them died after one and four years of chronic pacing. In one case tracheotomy could be closed definitively. Ventilatory insufficiency due to CAH and SCI can be treated even in children with diaphragm pacing, provided the indication for implantation, containing medical and social aspects, was made correctly. Diaphragm pacing probably will not lengthen life of severely injured children but it can increase the quality of their life and therefore should be preferred to positive pressure mechanical ventilation.

Adolescent↗
PubMed1996

The prefabricated combined scapula flap for bony and soft-tissue reconstruction in maxillofacial defects--a new method.

A concept for improving the precision of reconstruction of the maxilla in terms of form and function, including gnathologic, functional, and prosthetic aspects, is presented with a prefabricated combined scapula flap. In four cases, a bony flap from the lateral border of the scapula with osseointegrated titanium implants, covered with skin grafts and encapsulated with a Goretex sheet to create a stable soft-tissue coverage, was performed. Three months later, the prefabricated combined scapula flap was harvested and transferred to reconstruct a maxillary bony and soft-tissue defect in the face using microsurgical vascular anastomoses to the facial vessels. One flap was lost because of vascular thrombosis and was repeated successfully 1 year later. In each of the four cases, full dental rehabilitation and marked improvement of the facial contour was achieved in a single surgical intervention of the face. For this purpose, new radiodiagnostic methods for precise correlation between the maxillofacial defect and the donor area were use. With this new concept, an organ-specific reconstruction of soft-and bony-tissue defects of the alveolar ridge and the hard palate, with a pseudogingiva and teeth, is possible in an optimal way.

Adolescent↗
PubMed1995

Long term results of inflatable mammary implants.

In this retrospective study, the long term results of 167 inflatable mammary implants in 77 patients who underwent either breast reconstruction or augmentation between 1972 and 1990 were evaluated. All inflatable implants were manufactured by Heyer-Schulte/Mentor company, and were equipped with a posterior leaf valve (style 1800). The mean follow-up was 9 years (SD = 4.3). Complete deflation was found in 23.9% of the implants (22.2% deflation rate from 1972 to 1984 and 25.5% from 1985 to 1992). The incidence of this complication was significantly higher in patients who underwent previous open (p = 0.012) or closed (p = 0.038) capsulotomy. Severe contracture of the implant fibrous capsule (BAC 3 and 4) was found in 37.6% of the patients. Its incidence increased significantly when the postoperative blood loss (assessed by the volume of blood collected by suction drainage) exceeded 250 cc (p = 0.025). Neither the site of the implant (submuscular/subglandular) nor the indication for surgery (reconstruction/augmentation) influenced the rate of severe capsular contracture significantly in this retrospective study.

Adolescent↗
PubMed1995

The extended gracilis muscle flap for reconstruction of the lower leg.

The width of the gracilis muscle was measured before and after removal of the epimysium in 10 fresh cadavers. The average extent of muscle widening achieved by epimysium removal was over 100% (mean 112.6%; standard deviation 11.9%). This extended muscle flap enabled us to cover successfully even large soft tissue defects measuring up to 300 cm2. In 27 consecutive patients, soft tissue defects of the lower leg with exposed bone have been repaired by free tissue transfer of a gracilis muscle flap, covered with split skin grafts. The advantages of the gracilis muscle flap were the low donor site morbidity with almost no recognisable functional loss, the easy surgical access, the thin and flat shape of the muscle, and its adequate size after excision of the epimysium. Reconstruction with a gracilis muscle flap resulted in an inconspicuous, stable, and flat contour of the lower leg. The entire length of the vascular pedicle of the gracilis muscle was easily harvested in our patients by routinely dissecting the pedicle on both sides of the adductor longus muscle.

Adolescent↗
PubMed1995

Donor-site morbidity of the gracilis flap.

To determine whether there is a specific donor-site morbidity inherent in the elevation of the gracilis flap, we retrospectively examined 42 patients who underwent elevation of their gracilis muscles. We found, on dynamometric measurement, that the adduction strength of the hip joint was decreased by 11 percent when the gracilis muscle was elevated. This decrease in strength was not noticed by the patients. We also found an area of hypesthesia corresponding to the cutaneous territory of the obturator nerve in 40.5 percent of the patients. In addition, many patients were dissatisfied with the aesthetic appearance of the donor site, and a contour deformity of the thigh was present when a myocutaneous flap was elevated. Therefore, we conclude that the gracilis flap has a low but definite rate of donor-site morbidity. The advantages of the flap outweigh by far, however, the sequelae at the donor site.

Adult↗
PubMed1992

Long-term results of nervous tissue alterations caused by epineurial electrode application: an experimental study in rat sciatic nerve.

In order to evaluate the long-term effects of epineurial electrode application for functional electrical stimulation (FES) the left sciatic nerve of seven rats was exposed. Four ring-shaped stainless steel wire electrodes were sutured to the epineurium of each nerve in the same manner as performed clinically for carrousel stimulation in man. The nerves were reexposed 1 year after implantation and the stimulation threshold to obtain a tetanic contraction in the lower limb was determined for each electrode. Afterwards the animals were sacrificed. The electrodes were excised and cross sections of the sciatic nerve directly at site of the electrodes, 2-mm proximal and 2-mm distal to them were harvested for histologic and planimetric assessment of nerve lesions. The area of damaged neural tissue was expressed as a percentage of the total cross-sectional area within the perineural sheath. The sciatic nerves of the right side served as controls. The values for the stimulation thresholds ranged between 0.1 and 1.0 mA (mean 0.43 mA). By morphometric examination five of seven nerves were seen altered, the altered areas captured between 1% and 4.8% of the total cross-sectional area of the nerves within the perineural sheath. Besides two specimens, all altered nerve segments exhibited distinct signs of nerve fiber regeneration. The clinical implications of the results for long-term electrical stimulation, such as phrenic pacing, are discussed.

Animals↗
PubMed1991

Histological assessment of nerve lesions caused by epineurial electrode application in rat sciatic nerve.

The left sciatic nerve of 36 rats was exposed and four ring-shaped stainless steel wire electrodes were sutured to the epineurium of each nerve in the same manner as performed clinically for "carousel stimulation" in man. The rats were sacrificed 10 days (Group 1), 3 weeks (Group 2), or 3 months (Group 3) after implantation. The electrodes were excised, the nerves were embedded in Epon, and semithin sections were obtained for histological and planimetric assessment of lesions caused by the epineurially sutured electrodes. The right sciatic nerves served as controls. The total area of neural tissue within the perineurium was determined at three levels: at the site of the electrodes, 8 mm proximal, and 8 mm distal. The area of neural tissue damaged by the surgical procedure was expressed as a percentage of the total area. In Group 1, nine of 12 nerves showed lesions ranging from 0.39% to 25.39% of the total area of neural tissue, in Group 2 eight of 11 sciatic nerves showed lesions ranging from 0.24% to 13.03% of the total area, and in Group 3 five of 12 nerves showed lesions ranging from 0.21% to 4.96% of the total area. The pathologically altered areas in Groups 2 and 3 exhibited distinct signs of nerve fiber regeneration. The reasons for the decrease in damage from Group 1 to Group 3 and the clinical implications of the results for long-term electrical stimulation are discussed.

Animals↗
PubMed1989

[Reconstruction of deformities of the external ear].

Microtia is a rare malformation. Reconstruction of microtia is not a routine operation because of its rarity of occurrence and the complex deformity. In this paper the indication for surgical treatment, technique, results and complications are discussed. Two different operation methods were used in our patients. A multiple-stage and a single-stage reconstruction procedure. We used autogenous rib cartilage. Five of the seven treated patients came to the follow-up examination. Reconstruction was performed 2 years ago in two cases and between 4 and 12 years ago in three cases. Our patients were content with the result in so far as they would be prepared to undergo treatment again. Carefully built rib framework is an essential prerequisite for a successful postoperative result. Microtia represents a greater psychological problem than a cosmetically imperfect result after reconstruction.

Adolescent↗