Susanna Kauhanen

Microvascular reconstruction in children-a report of 46 cases.

BACKGROUND : We report microvascular free tissue transfers in pediatric patients in a retrospective series. METHODS : Forty-six children were treated in collaboration between the departments of Pediatric Surgery and Plastic Surgery, Helsinki University Hospital between 1986 and 2004 for microvascular free flap surgery. Trauma, tumor resection, congenital malformation, meningococcal septicaemia, and scars caused the tissue defects. The mean follow-up was 50 months. RESULTS : The overall success rate was 96%. Twenty-five free flaps were transferred to the lower extremity. The most used flap was vascularized fibula. Preoperative angiography or intraoperative anticoagulants were not routinely used. Early reoperations were needed in four cases due to hematoma and in four cases due to thrombosis or impaired blood flow. All attempts of reanastomosis lead to salvage of the flap. CONCLUSION : In cases of severe tissue defects in pediatric patients, microvascular free flap reconstruction is a treatment of choice. A multicenter study for guidelines on preoperative assessment and antitrombotic therapy in pediatric microsurgery is warranted.

Skeletal muscle injury and repair: the effect of disuse and denervation on muscle and clinical relevance in pedicled and free muscle flaps.

Skeletal muscle is prone to injury upon trauma or nerve damage. In reconstructive surgery, it is an interesting spare part. Fortunately, skeletal muscle is capable of extensive regeneration. Satellite cells, quiescent myogenic precursor cells, become activated following muscle injury: they divide and form myoblasts, fuse into myotubes, and finally mature to myofibers. Denervation in muscle or muscle flaps leads to myofiber atrophy, fibrosis, and fatty tissue infiltration. Experiments show that muscle flaps that are reinnervated also display a fair amount of atrophy. Muscle mass is better preserved after motor innervation than sensory innervation. Clinical data imply that innervation of the muscle flap does not improve volume preservation significantly compared with denervated flaps. In addition, the softness of the flap remains the same whether the flap is innervated or not. Innervation of the flap seems to be needed only if functional muscle reconstruction is the goal. If reinnervation is successful but the muscle is kept short, disuse atrophy will still proceed. Muscle flaps should therefore be placed into their original length.

Satellite cell proliferation, reinnervation, and revascularization in human free microvascular muscle flaps1

BACKGROUND Satellite cell proliferation, reinnervation, and revascularization were studied in human nonreinnervated free microvascular muscle flaps to characterize mechanisms of muscle regeneration after flap surgery. MATERIALS AND METHODS Patient biopsies (n = 19) were taken at operation and five timepoints up to 9 months after operation, and corresponding clinical data were obtained. Immunohistochemistry for Ki-67 was used to detect proliferating satellite cells, CD-31 to identify endothelial cells, and S-100 and PGP 9.5 proteins to detect reinnervation. RESULTS Two weeks after operation, the expression of PGP 9.5 and S-100 had virtually disappeared in all larger nerve fibers and half of smaller nerve fibers. By 6 months, however, a strong expression of PGP 9.5 and S-100 had reappeared in larger nerve fibers in three of four flaps, suggesting that reinnervation had taken place. The number of mitotic satellite cells already peaked at 2 weeks, indicating onset of muscle regeneration. The number of intramuscular capillaries first increased but later decreased to lower than original level. Flaps with more muscle volume showed more reinnervation and satellite cell mitotic activity. In cases of a delay occurring in reconstructive surgery, a low level of reinnervation was seen. CONCLUSION Three patients of four showed spontaneous muscle reinnervation in microvascular free flaps with satellite cell activation followed by restored morphology. Late reconstruction and obesity lead to poor reinnervation, placing emphasis on timing of surgery and patient selection.

Early muscle changes after immobilization. An experimental study on muscle damage.

Immobilization of the rabbit knee in extension has previously been shown to damage the vastus intermedius profundus (VIP) muscle. To examine the mechanism of the early stages of the muscle damage, the authors studied creatine kinase activity in serum, and both light and electron microscopic changes in the affected muscle. The right knee was immobilized in an extended position using a splint, and thigh muscles were removed at various intervals, up to 48 hours after immobilization. The left hindlimb served as a control. Creatine kinase levels in serum rose ten hours after the onset of the immobilization. The enzyme levels reached a substantial peak by 24 hours, and plateaued thereafter. Light microscopic changes were not observed within 48 hours, but in electron microscopy distinct mitochondrial swelling and crystal abnormalities were seen as early as ten hours. The ultrastructural changes of mitochondria remained constant for up to 36 hours and decreased thereafter. At 48 hours of immobilization, also myofibrillar disorganization was seen. It appears that immobilization of the rabbit knee in extension rapidly leads to signs of remarkable damage to the VIP muscle. These suggest leakage of the cell membrane and metabolic disturbances. The ultrastructural changes observed share common features with muscle damage caused by ischemia, uncoupling agents, and inherited mitochondrial myopathies.

Recovery of skeletal muscle after immobilization of rabbit hindlimb

The histopathology of the deep portion of the vastus intermedius (VIP) muscle from 13 rabbit hind‐limbs immobilized in shortened position for 2–2.5 (n=4), 3 (n = 3), 14 (n = 3) and 28 (n = 3) days and VIP muscles from 13 rabbit hindlimbs immobilized for the same time periods and subsequently remobilized for 4 weeks were compared. After 3 days of immobilization the VIP muscles displayed a 15% (p<0.004) decline in muscle fibre diameter. By 2 weeks of immobilization fatty change was prominent and muscle fibre diameters had decreased to 56% (p<0.0001) of control values. By 4 weeks of immobilization severe fibrotic damage of myofibres was observed and fibre diameters had decreased to 47% (p<0.0001) of control values. Three days of immobilization followed by 4 weeks of remobiliza‐tion led to marked fatty change as well as an increase in connective tissue in the affected VIP muscles. The muscle fibre diameter in these muscles was 71% (p<0.0001) compared to the VIP immobilized for 3 days and 61% (p<0.0001) compared to the control muscles. By 2–4 weeks of immobilization the subsequent remobilization did not aggravate the initial damage. We conclude that the morphology of VIP muscle immobilized for 3 days suffers more during a subsequent remobilization period than those immobilized for 14–28 days. These findings focus attention on the mechanisms operating at the onset of disuse muscle atrophy.

Reduction Mammaplasty as an Outpatient Procedure: A Retrospective Analysis of Outcome and Success Rate:

Background and Aims: Reduction mammaplasty is an increasingly common plastic surgical procedure. In the United States, majority of breast reductions are performed as outpatient surgery. In European public health care, outpatient breast reductions have still been rare. Our aim was to retrospectively determine clinical outcome and the success rate of outpatient reduction mammaplasty. Material and Methods: A total of 110 consecutive patients underwent bilateral reduction mammaplasty with a minimum resection of 200 g per breast in an outpatient unit between 2006 and 2009. A comparison group consisted of 28 inpatients. Demographic data and pre-, intra-, and postoperative events as well as complications were recorded. Results: A total of 83 outpatients (75%) were successfully discharged on the day of operation. Reasons for unexpected overnight admission were lack of adult company for the first postoperative night (13 patients, 12%), surgeon’s wish (4 patients, 4%), hematoma requiring evacuation (5 patients, 5%), nausea (3 patients, 3%), and pain (2 patients, 2%). Minor complications, especially delayed healing, were common (45 patients, 41%), but major complications were rare (18 patients, 16%). Complication rate was not increased in the outpatient group. Increased duration of operation correlated with increasing complications. Conclusion: Reduction mammaplasty can be successfully and safely performed as an outpatient procedure in European public health care.

Vascular Endothelial Growth Factor and Its Receptors Are Expressed in Human Nerve Grafts

Vascularization and angiogenicity of human nonvascularized nerve grafts in the second stage of facial reanimation were studied. Immunohistochemistry for endothelial markers (CD-31) and vascular endothelial growth factor (VEGF) and its receptors Flt-1 and Flk-1 was performed on distal end biopsies from 35 cross-facial nerve grafts. In grafted nonvascularized nerve, density of vascular structures (also clearly immunopositive for VEGF and both receptors) showed a mean of 166 vessels (range 78 to 267) per unit area, corresponding to control values. In addition, VEGF was expressed in axons and perineural structures. In control samples, VEGF expression was low and occurred in the myelin sheath. In nerve grafts, expression of Flt-1 and Flk-1 (less intense) was seen in axons and perineural structures. A higher density of vessels was associated with lower VEGF expression (not significant). In short, expression of VEGF and its receptors is described in human nerve grafts and compared with basic histology and p75 nerve growth factor receptor expression of the nerve graft and functional outcome of patients.

Cost savings in outpatient versus inpatient reduction mammaplasty

BACKGROUND AND AIMS Reduction mammaplasties are increasingly performed as outpatient procedures. Cost savings are assumed, but published data on the subject are scarce. The aim of this study was to retrospectively determine the possible cost savings achieved by performing reduction mammaplasties as outpatient procedures. MATERIAL AND METHODS Reduction mammaplasty was performed for 90 outpatients and 44 inpatients, with comparable health status. Demographic, surgical, and complication data were collected retrospectively. Data on the costs of the entire treatment process were acquired and statistical analyses performed. RESULTS The average total cost of the process was 5039 € for inpatients and 4114 € for outpatients. Thus, the total costs were 925 € (18%) lower for the outpatient procedures. On average, cost saving per patient was 294 € (43%) on ward expenditures. Higher ward expenditure was a statistically significant cause of the increased cost of the inpatient group on uni- and multivariable analyses; however, for total costs, the effects of complications and reoperations were significant. CONCLUSIONS Reduction mammaplasty performed as an outpatient procedure results in up to 18% cost savings compared with inpatient treatment.