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Biomedical subjects

J Vuola

Publications and source records attributed to J Vuola.

14 recordsLinked to original sources
PubMed2005

Surgery in the air--evacuating Finnish tsunami victims from Thailand.

In connection with the Asian tsunami disaster on December 26, 2004, a specially equipped Finnair B-757 airplane capable of evacuating badly injured patients was remodeled into an ambulance airplane. The vehicle could take up to 22 severely injured or ill patients and intensive care and limited surgical procedures could be provided to the patients. The plane was manned with a civilian medical team of 37 physicians and nurses. The plane left for Thailand to evacuate the most severely injured Finnish citizens within 10 hours of the evacuation decision. A total of 14 patients including 4 critically ill (two on ventilator) were transferred to Helsinki within 32 hours of takeoff. The medical team included a general, an orthopedic and a plastic surgeon. Soft tissue wounds, some of them severely infected, were the most common injuries, followed by extremity fractures and head injuries. The surgical procedures that were performed mid-air included wound surgery, to remove necrotic tissue, and external fixation and fasciotomy for a lower extremity fracture. The facilities under these circumstances would allow performing life-saving procedures to maintain airway and breathing, and surgical procedures of the soft tissues, extremity and pelvic fractures. Cavitary surgery would require additional equipment and resources.

Air Ambulances↗
PubMed2002

Maintaining a glycerolized skin bank--a practical approach.

The Helsinki Burn Unit admits around 120-140 patients a year and, of these, 20-30 need intensive care. Before 1995, fresh, non-tested cadaver skin was used to cover widely meshed autografts in large burns. In 1995, we founded a skin bank to avoid the problems encountered in the use of fresh cadaver skin: contamination by viruses or bacteria, shortage of available skin, the occasionally poor quality of the cadaver skin, and the inconvenience of harvesting skin in the mortuary. Crucial to the work of the Skin Bank has been cooperation with the Transplantation Unit of our hospital. This reduces paperwork and guarantees the quality of the donors. It also enables us to harvest skin only from tested multiorgan donors in an operating theater setting. Also important is a well organized team to ensure the procurement of a sufficient amount of good-quality allografts. This requirement raises the otherwise low costs of a glycerolized skin bank.

Burns↗
PubMed2001

Evaluation of blood flow in free microvascular flaps.

Free flap surgery is routine today, yet little is known of its pathophysiology. In this study, the authors evaluated the hemodynamics in different types of free microvascular flaps, by measuring intraoperative transit-time flow. Eighty-six free transplants--21 free TRAM flaps for breast reconstruction, 18 radial forearm flaps for head and neck reconstructions, and 47 muscle flaps for head and neck, trunk and lower extremity reconstructions--were studied. Donor artery flow was highest in the radial artery (mean: 57.5 +/- 50 (SD) ml/min) but dropped (p < 0.001) to one tenth (6.1 +/- 2 ml/min) after anastomosis. The flow was lowest (4.9 +/- 3 ml/min) in the recipient artery of the TRAM flap but, after anastomosis, increased significantly (13.7 +/- 5 ml/min) to the level of the flow in the donor artery. The donor-artery flow in muscle flaps had a mean of 15.9 +/- 11 ml/min, and it significantly increased after anastomosing (23.9 +/- 12 ml/min). Weight-related intake of blood was highest in the radial forearm flap (18.5 +/- 6 ml/ min/100g) and lowest in the TRAM flap (2.5 +/- 1 ml/min/100g). The study showed that blood flow through a free microvascular flap does not depend on recipient artery flow. Even low-flow arteries can be used as recipients, because the flow increases according to free-flap requirements. The blood flow through a free microvascular flap depends on the specific tissue components of the flap.

Adolescent↗
PubMed2000

Natural coral as bone-defect-filling material.

Natural coral (NC) has been studied experimentally and clinically as a bone substitute, but its resorption rate and possible replacement by bone still need to be defined in humans. In this study bicortical bone was harvested from the iliac crest of 10 patients. The defect was filled with a NC block, and changes were monitored by X-rays and quantitative CT scans for a mean of 2.1 years. A biopsy was taken at 1 year. The purpose of the study was to investigate the resorption rate and pattern of NC (Porites) implants and the replacement, if any, of the implant by new bone. The blocks underwent centripetal resorption, but all the blocks still could be detected by X-rays and CT scans at the end of the follow-up period. The density of the remaining block did not change. Seven of the 10 implants were smaller than 50% of their original size at the end of the study. Bone ingrowth could be observed only in two of seven biopsies. One implant had to be removed after 1.7 years due to infection. The study shows that resorption of natural coral proceeds centripetally and apparently more rapidly when accompanied by tissue ingrowth. None of the blocks resorbed completely, and the defect at the iliac crest had not been restored by the end of the study.

Adolescent↗
PubMed1997

Return to employment after burn.

The increase in the survival rate of burned patients has stressed the need to study their rehabilitation. The purpose of our study was to characterize the factors influencing such patients' return to work. We conducted a mail survey among 316 patients aged 15-65 years, treated at Töölö Hospital Burns Unit between 11 November 1988 and 31 December 1994. Of 175 participants, 130 (74 per cent) were men and 45 (26 per cent) women. The mean TBSA was 14.0 per cent, mean FT 6.4 per cent and the mean time of hospital treatment (TOT) 17.5 days. Statistical significance was calculated by Mann-Whitney U test, Kruskall-Wallis one-way analysis of variance and Chi-square test as appropriate, with a probability level of 0.05. In the study, 54 per cent of patients whose burn area was 1-10 per cent, returned to work within 2 months. No difference was found between patients who had hand burns and those who had burn injuries in other parts of the body. Patients who did not return to work were significantly older (mean age 45 years) than those who did (mean ages varying from 33 to 36 years; P < 0.05). Total body surface area burned (TBSA), FT, TOT, age and employment status at the time of injury were the factors predicting the resumption of working ability after burn injury.

Adolescent↗
PubMed1997

Microvascular free flaps in head and neck cancer surgery in Finland 1986-1995.

Microvascular free tissue transfer has in many cases replaced classic flap techniques and is now an established workhorse for head and neck reconstructions. In this retrospective study the over 300 patients, who had microvascular free flap reconstructions in head and neck cancer surgery in Finland during a 10-year period (1986-1995) were reviewed. The operations were performed in the University Hospitals by plastic surgeons, ENT specialists or maxillofacial surgeons. The cases consisted of defects resulting from resection of oral cavity tumors (63%), mid- or upper-face and skullbase tumors (20%) and hypopharyngo-esophageal tumors (17%). The series includes a wide range of flap types and analyses flap outcome and complications. A total of 313 cases was reconstructed by 317 flaps (forearm flaps 47%, latissimus dorsi flaps 19%, free jejunum or colon transfers 15%, free iliaca crest flaps 8% and other flaps 11%). Thrombosis of one of the vessels and haematoma were the most frequent causes of failure in microvascular free tissue transfer. A total flap necrosis occurred in 27 (8.5%) and a partial necrosis in 12 (4%) patients. The most reliable flap in terms of survival was the radial forearm flap. The ever-improving success of microvascular free tissue transfer has made it a useful procedure for head and neck reconstructions. There is also a growing need for microvascular team surgery in the field of head and neck cancer therapy.

Female↗
PubMed1996

Bone marrow induced osteogenesis in hydroxyapatite and calcium carbonate implants.

In this experimental study, blocks of natural coral (calcium carbonate) and its structurally similar derivate in the form of hydroxyapatite (calcium phosphate) were implanted in rat latissimus dorsi muscle with autogenous bone marrow to compare their bone-forming capability. A block without marrow placed in the opposite latissimus muscle served as a control. The animals were killed at 3, 6 and 12 weeks and, in the hydroxyapatite group, also at 24 weeks. The sections were analysed histologically and histomorphometrically. Bone was found only in implants containing bone marrow. Bone formation was significantly (p < 0.05) higher in coral than in hydroxyapatite implants at 3 weeks (10.8% versus 4.8%) and at 12 weeks (13.7% versus 6.3%, bone/total original block area). At 12 weeks all the coral implants had lost their original structure, and the cross-sectional area of the block had diminished to 40% of the original area.

Animals↗
PubMed1995

Filling the bone defect with osteogenic material. An experimental study.

In this experimental study with bone defects, we focussed on the one hand on external and internal osteogenic callus formation after filling the defect and on the other on the osteochondrogenic differentiation capacity of 4-day-old fibrous-like callus grafts and 12-day-old woven bone grafts in an osteogenic environment. A standard cortical bone defect of the femur was created in 95 young rats. The defect was filled with a cortical bone graft and 4- and 12-day-old callus grafts. The grafts were transplanted as such or in Nucleopore chambers. Follow-up was done at 1, 2, 3 and 6 weeks. The osteochondrogenic tissue formed was studied histologically and histomorphometrically. The results suggest that the filling of the bone defect had no influence on the primary external and internal osteogenic callus formation at 1 and 2 weeks. At 3 and 6 weeks in the chamber groups the persisting internal bridging woven bone was converted into more compact lamellar bone whereas periosteal callus remained at the edges of the defect. In the other groups at 3 and 6 weeks the normal shape of the cortex was reconstituting. Four-day-old fibrous-like callus formed bone in the Nucleopore chamber, indicating that fibrous-like callus tissue at 4 days contains osteogenic cells. Twelve-day-old callus consisting of woven bone was partially differentiated to cartilage, showing that woven bone contains cells capable of chondrogenic differentiation.

Animals↗
PubMed1995

Regeneration of defects in articular cartilage with callus and cortical bone grafts. An experimental study.

Cartilage regeneration was studied in an experiment in rats. A standardised full-thickness articular cartilage defect was created and autogenous 12-day-old callus or cortical bone graft was transplanted into it, or the defect was left empty. The follow up periods were three, six, 12, and 24 weeks, and each subgroup consisted of five animals. A total of 60 animals were operated on. From six weeks onwards hyaline-like cartilaginous tissue had started to develop at the edges of the defect in all three groups. In the middle section of the hole, however, the picture was different; at 24 weeks none of the specimens in the defect group, two of the five in the callus graft group, and all five in the bone graft group had developed full-thickness, hyaline-like cartilaginous regeneration. The hyaline-like cartilaginous tissue in the medical segment was hypocellular when analysed by histomorphometry. On scanning electron microscopy the surface of the reparative tissue looked fibrillated in all specimens from the three groups.

Animals↗
PubMed1992

Histology and histomorphometry of bone regeneration after experimental injuries.

Reparative callus formation upon tubular bone was studied after surgical injuries of different degrees. Thirty-seven young rats were divided into three groups. In the periosteum group the bone was scraped, in the fissure group we made a slit reaching the medulla, and in the defect group a standard defect was sawn. Rats were killed at 6, 12 and 18 days. The formed callus was studied histologically and histomorphometrically. The results suggest than even the primary osteochondrogenic callus formation is dependent on the mode of injury. At six days the three groups differed both qualitatively and quantitatively in regard to callus formation. At 12 and 18 days the total area of woven bone was proportional to the degree of trauma according to the linear regression line Y = 0.883 x X + 0.226 (r = 0.876, P less than 0.001). In the fissure and defect groups reparative bone filled the hole proportionally to the same extent. Periosteal and endosteal woven bone formed round the bone. Medullary bone formation was limited mainly to the area immediately adjacent to the trauma, the result being a cylinder-shaped callus. Cartilage formation was most abundant at six days and was related to the amount of woven bone in the external callus (r = 0.854, P less than 0.001) and to the trauma area (r = 0.707, P less than 0.05).

Animals↗
PubMedDate not supplied

Compressive strength of calcium carbonate and hydroxyapatite implants after bone-marrow-induced osteogenesis.

Natural coral and structurally similar porous hydroxyapatite (HA) have been used as bone substitutes. They are not osteoinductive but bone formation can be induced by marrow cells, even in extraosseal sites. In our previous study we induced bone formation in porous coral and HA after having implanted the materials in intramuscular pockets in rat. New bone formed only in HA or coral implants soaked with marrow cells; fibrous tissue ingrowth alone was observed in the controls (without marrow). In the present study we examined the effect of tissue ingrowth on the mechanical properties of coral and HA implants obtained in a similar process to that used before. At 12 weeks the compressive strength of HA was higher in the marrow group than in the controls; it was also higher than that of the wet unimplanted material. The HA blocks did not show resorption. Coral resorbed quickly and lost its compressive strength, which was originally higher than in HA. At three weeks the marrow group was stronger than the control specimens. After six weeks only the marrow group, but not the controls, could be tested. Bone ingrowth seemed to maintain the strength of the coral implant even if it was dissolving. The mechanical strength of both materials was comparable to that of cancellous bone.

Animals↗