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Biomedical subjects

D Lidman

Publications and source records attributed to D Lidman.

At least 19 recordsLinked to original sources
PubMed2001

Changes in a rat facial muscle after facial nerve injury and repair.

This study describes changes in a rat facial muscle innervated by the mandibular and buccal facial nerve branches 4 months after nerve injury and repair. The following groups were studied: (A) normal controls; (B) spontaneous reinnervation by collateral or terminal sprouting; (C) reinnervation after surgical repair of the mandibular branch; and (D) chronic denervation. The normal muscle contained 1200 exclusively fast fibers, mainly myosin heavy chain (MyHC) IIB fibers. In group B, fiber number and fiber type proportions were normal. In group C, fiber number was subnormal. Diameters and proportions of MyHC IIA and hybrid fibers were above normal. The proportion of MyHC IIB fibers was subnormal. Immediate and delayed repair gave similar results with respect to the parameters examined. Group D rats underwent severe atrophic and degenerative changes. Hybrid fibers prevailed. These data suggest that spontaneous regeneration of the rat facial nerve is superior to regeneration after surgical repair and that immediacy does not give better results than moderate delay with respect to surgical repair. Long delays are shown to be detrimental.

Adenosine Triphosphatases↗
PubMed2001

Specificity of reinnervation and motor recovery after interposition of an artificial barrier between transected and repaired nerves in adjacency--an experimental study in the rat.

Non-specific re-innervation of target organs caused by misdirected axonal growth at the repair site is regarded as one reason for a poor functional outcome after peripheral nerve transsection and repair. This study investigates the rate of aberrant re-innervation and its influence on motor recovery in the rat sciatic nerve using artificial sheets as barrier between tibial and peroneal nerves. The sciatic nerve was transsected and repaired as follows: epineural sutures (A x 6), fascicular repair of tibial and peroneal nerves respectively (B x 8), and the same as in group B, but separating both nerves using an Integra-sheet with silicone (C x 8), or Integra without silicone (D x 8). As control, solely the tibial nerve was transsected and repaired (E x 5). Final investigations after 4 months revealed that in group C, 50% of the Integra-silicone sheets were dislocated. No dislocation was found in group D. Muscle contraction force of the gastrocnemius muscle was significantly higher in group E as compared to all other groups. However although not significant, group D showed a consistently higher muscle contraction force than groups A, B, and C. Histology in groups A, B, and C with dislocated sheets demonstrated multiple axons growing from the tibial to the peroneal nerve and vice versa. In groups D and E, no such axonal growth was visible. These findings were confirmed by a significantly higher rate of specific reinnervation of the soleus muscle using sequential retrograde double labelling technique. Results of this study suggest that an artificial sheet such as Integra bears the potential of preventing aberrant re-innervation between repaired adjacent nerves resulting in improved motor recovery. Clinically, this technique may be of importance for brachial plexus, sciatic nerve, and facial nerve repair.

Animals↗
PubMed2000

Severe contusion of the femoral vessels in rats alters tissue oxygenation and microvascular blood flow regulation in the skeletal muscles of the limb.

BACKGROUND: Severe contusion of an artery often presents clinical problems in that it affects flow distal to the injury. However, the effect of a contusion on the microvascular flow regulation in the distal part of the limb is still largely unknown. METHODS: A multipoint microelectrode technique was used to assess both tissue oxygenation (PtO2) and microflow (hydrogen clearance) on the skeletal muscle surface in a standard contusion injury to the femoral vessels in rats. RESULTS: A significant increase in and an altered distribution of (PtO2) as well as a reduction in and altered distribution of microflow on the muscle surface distal to the injury was found in all animals (n = 27) compared with the uninjured control leg. These findings could not be reproduced experimentally by sympathectomy or when the adjacent skeletal muscle alone was injured. CONCLUSION: The results suggest that the changes observed distal to the injury are of vascular origin, possibly as a result of endothelial damage at the site of the contusion.

Animals↗
PubMed1999

The functional result two years after a microsurgical penile replantation. Case report.

We describe the technique of microsurgical penile replantation and a case followed up after two years. The patient was a young man with decompensated schizophrenia who emasculated himself with a kitchen knife. A particularly good functional result was achieved including restoration of sensation in the penile shaft and in the glans, and return of erectile capacity.

Adult↗
PubMed1997

Clinical experiences of the pedicled extensor digitorum brevis flap.

The extensor digitorum brevis muscle of the dorsum of the foot is well suited both anatomically and from the point of functional deficit to use as a pedicled muscle flap in the lower parts of the leg. We demonstrate the extensive anatomical reach of the flap and our results in a series of 16 patients who required reconstruction, in 15 of whom the flap survived successfully. Even the flap that failed partly achieved its goal in that its application induced enough granulations on the exposed anterior tibial tendon for a skin graft to take.

Adolescent↗
PubMed1997

Repair of the mandibular branch of the rat facial nerve through transmedian grafting in one or two stages. Morphological evaluation.

This study examined by electron microscopy the normal fibre composition of the mandibular branch (MB) of the rat facial nerve and the outcome of axon regeneration in the MB after transmedian grafting in one or two stages. The average normal MB contained 2,185 axons, 17% of which were unmyelinated. The myelinated axons had a unimodal diameter distribution (range 1.5-9.5 microns, mode 4.5 microns). After superior cervical ganglionectomy, the MB lost 1/3 of the C-fibres and 10% of the myelinated axons. In neonatally capsaicin-treated rats the occurrence of unmyelinated axons was reduced by about 50%. After repair in one or two stages the MB contained more myelinated and unmyelinated axons than normal. The myelinated axons showed a unimodal size distribution with a subnormal diameter range. Statistical comparisons showed that MBs from both experimental groups were significantly abnormal with respect to total axon number as well as numbers of unmyelinated and myelinated axons. In these respects the grafted MBs did not differ significantly from each other. However, the myelinated axons in MBs from one-stage cases showed larger mean and maximum diameters compared to MBs from two-stage cases. These data suggest that the normal MB of the rat contains myelinated and unmyelinated sympathetic axons and that about half the C-fibres in the normal MB come from capsaicin-sensitive sensory neurons. The comparison of the two reparative procedures used provides evidence in favor of the one-stage alternative.

Animals↗
PubMed1996

Simplified external fixation for primary management of severe musculoskeletal injuries under war and peace time conditions.

This study was undertaken to document whether a basic set of a new unilateral external fixation device could provide sufficient stability in complex musculoskeletal injuries involving upper and lower extremities and in patients with unstable pelvic ring disruptions. The initial clinical evaluation was performed in Sweden (stage 1) followed by field evaluation at the Swedish Field Hospital during the Mogadishu conflict in Somalia (stage 2). In stage 1, there were 90 patients with 116 acute limb injuries and six patients with an unstable pelvic ring disruption. Ninety limb injuries and all six pelvic fractures were primarily stabilized by the external fixation device. The other 26 fractures were managed at the index operation with intramedullary nailing, open reduction, and internal fixation or cast immobilization. Twelve patients had a local pedicle or free vascularized flap for soft tissue coverage. One multiply injured with an open Gustilo IIIB tibial shaft fracture had an early amputation. The basic set provided adequate stabilization for soft tissue recovery in 89 limb injuries (89 of 90), thereby providing optimal conditions for continued management to skeletal consolidation in 88 patients. Hemodynamic stabilization was achieved in all six patients with unstable pelvic fractures. In stage 2, there were 63 patients with war injuries and 33 patients injured in traffic accidents. All were managed under field conditions. The basic set was sufficient for soft tissue recovery in all 96 cases. It is concluded that the rigidity of this device is adequate for stabilization of severe musculoskeletal injuries requiring major surgical procedures. In addition, the simplicity of this device, which allows for only a limited number of possible configurations makes it suitable for inexperienced surgeons working under war or mass-casualty conditions to manage these complex musculoskeletal injuries.

Adolescent↗
PubMed1994

Microvascular surgery after severe contusion of the femoral artery in rats.

Thirty three rats were subjected to severe contusion of the femoral region by a heavy falling object. The injury was directed towards the palpated femoral vessels in a standard way as described in a previous study. One hour after the injury microvascular surgery was performed on the damaged part of the femoral artery. In 17 animals the artery was transected at the centre of the injured part. The ends were then anastomosed without resection. In the remaining 16 animals the damaged part of the artery was resected and a long arterial graft taken from the opposite, uninjured leg was substituted. Postoperatively the animals were observed for two hours. Arterial patency was evaluated immediately after injury, at the end of operation and after one and two hours. After the animals had been killed, transverse sections of the damaged arteries from 28 of the 33 were examined by light microscopy. Signs of severe contusion was found in 82% of the specimens. The overall number of injured arteries was 97%. The patency rate after transection treated by direct suture was 71%, and after resection and vascular grafting it was 100%.

Anastomosis, Surgical↗
PubMed1994

Lymphoedema of the lower extremities after surgery and radiotherapy for cancer of the cervix.

Fifty-four women were examined to find out the incidence of lymphoedema after treatment of cancer of the uterine cervix. The women had all had total hysterectomy and excision of the pelvic lymph nodes and 53 had also received radiotherapy. The character and severity of problems experienced by the patients in their daily living were assessed by an interview. Twenty-two of the patients (41%) had a unilateral increase in volume of 5% or more in one leg compared with 15 healthy controls in whom the difference between limbs did not exceed 4%. Of the 54 patients 15 (28%) had a slight swelling (> 5% volume increase); 3 (6%) had moderate swelling (> 10% volume increase); and 4 (7%) had severe swelling (> 15% volume increase), which was interpreted as treatment-induced lymphoedema. Twelve (22%) of the patients had lymphoedema that was severe enough to cause symptoms.

Activities of Daily Living↗
PubMed1992

Team approach to tibial fracture. 37 consecutive type III cases reviewed after 2-10 years.

During a 10-year period, we managed 35 patients with 37 cases of Type III open tibial fractures, 15 cases within 1 week and 22 as late referrals. In all cases, simultaneous assessment and management by a microvascular and an orthopedic surgeon were mandatory throughout the treatment period. 6 of the 15 acute cases had a primary amputation. Of the remaining 31 cases, limb salvage was possible in 27. 31 flaps, pedicle and microvascular free flaps were used. Major complications occurred in 6 cases, but in 27 cases infection-free solid union was obtained. At long-term follow-up, average 5 years, the function was good or acceptable in 23 cases. We conclude that: (1) patients with Type III tibial injuries should preferably be transferred within a week after injury to a hospital where major reconstructive procedures are commonly performed, (2) early soft tissue coverage is essential in the management of these injuries, (3) unilateral external fixation should be the preferred technique of stabilization, and, finally, (4) plastic surgery expertise is important in management of severe tibial fractures.

Adolescent↗
PubMed1991

The effect of severe contusion on the vessels of the femoral region. An experimental morphological study.

Forty-one rats were subjected to a single blow in the femoral region from a heavy falling object. The contusion was directed towards the palpated femoral vessels in a standard manner. Transverse sections of the femoral artery and vein with branches, including adjacent muscle, were taken at 30 min, 24 hours, 2 weeks and 1 and 3 months after the injury and evaluated by light microscopy. The injuries to the femoral vessels and their branches at 30 min and 24 hours varied from partial destruction of the internal elastic lamina only to crush injury of the media together with thrombosis. Bleeding was always present. In the most severely injured arteries the vessel wall had ruptured. The findings at 2 weeks and 1 and 3 months were more discrete. The femoral vessels had remained patent, sometimes with permanent damage to the internal elastic lamina and rearranged architecture of the elastic tissue in the media. In a few cases recanalized thrombi were seen in arterial branches. Fibrosis of the femoral muscle was found at the level of trauma. Despite a single serious blow to the femoral region, however, there was no permanent major injury to the femoral artery or vein.

Animals↗
PubMed1987

Mechanical anastomosis of small arteries and veins with the unilink apparatus: a histologic and scanning electron microscopic study.

A new method for mechanical anastomosis of small vessels--the Unilink device--has been tested in 23 rabbits. A total of 81 arterial and venous anastomoses were performed. One of the arterial anastomoses were thrombotized, while the remaining 80 anastomoses were fully patent at 2 or 16 weeks. The repair process at the anastomotic site was very rapid both in arteries and veins. The endothelialization was complete at 2 weeks, but a marked atrophy of the media was noted in the arterial anastomoses. The same phenomenon was observed in the venous anastomosis, but to a much lesser degree. Thrombus formation was extremely rare, and the atrophy of the media did not seem to affect the patency rate. The experiment has confirmed that the Unilink method provides a very safe, fast, and simple way to perform microvascular anastomoses.

Animals↗
PubMed1987

Reconstruction of soft tissue defects including the Achilles tendon with free neurovascular tensor fascia lata flap and fascia lata. Case report.

The combined loss of the Achilles tendon and the overlying soft tissue in the young ambulant patient with expectations of a normal life is a challenge. These patients need not only skin coverage but also dynamic, functioning repair. Two cases of major defects after tumour resection are presented. In each case the tendon was reconstructed using the remaining gastrocnemius aponeurosis reinforced with fascia lata. This was covered by a free tensor fascia lata (TFL) flap. In one of the cases the flap was transferred as a neurovascular free flap.

Achilles Tendon↗
PubMed1986

Patency, blood flow and histologic characteristics in end-to-end and end-to-side arteriovenous fistulas. Comparisons in an experimental model.

Experimental arteriovenous fistulas of end-to-end (ETE) and end-to-side (ETS) type were created with microsurgical technique in rabbits between the carotid artery and the facial vein. Blood pressure and blood flow through the fistulas were registered during the operation and the flow capacity (flow/BP) was calculated. Evaluation was made at 2 hours, 1 day, 1 month and 3 months. Immediately after completion of the anastomosis there was no statistically significant difference in blood flow capacity between the ETE and the ETS group. At 1 month the flow capacity had increased significantly in the ETS, but not in the ETE group. At 3 months 3/5 of the ETS anastomoses remained patent, but all the ETE types were occluded. Histologic findings included severe intimal thickening at the anastomotic level and on the venous side of the anastomosis at 1 and 3 months. The study indicated that late blood flow and patency may be greater in ETS than in ETE arteriovenous fistulas.

Animals↗
PubMed1984

An anastomotic device for microvascular surgery: evolution.

A new anastomotic device is demonstrated that is suitable in microvascular surgery for repairing severed blood vessels and inserting vein grafts. Initial pilot studies indicate a 100% patency rate for vessel anastomosis, and a one-year study produced a 96% success rate. However, histological examination revealed notable vessel deterioration with a rigid device. Therefore, an absorbable anastomotic coupler was developed that demonstrates a high patency rate (92%) in both arteries and veins, with substantial absorption of the device by 70 days. Healing at the anastomotic site was qualitatively similar to that obtained with a sutured anastomosis; there was endothelialization by 14 days and absorption of the device by 70 days.

Animals↗