Valdemar Skoog

The Cartilaginous Potential of the Perichondrium in Rabbit Ear and Rib

In an experimental study the cartilaginous protential of the rabbit ear perichondrium has been compared with that of the rib in vivo and in vitro. Perichondrium was transferred as free autologous grafts to the subcutaneous tissue on the scalp and as loose bodies into the knee joint. The presence of cartilage in the grafts was examined after six weeks. In vitro explants of rabbit perichondrium from the ear and the rib were maintained in an organ culture system. The presence of cartilage was analyzed after one to three weeks. Rabbit perichondrium from the rib appeared to have a greater cartilaginous potential than that from the ear both in vivo and in vitro. Chondrogenesis in perichondrium was demonstrated in vitro.

Identification Of Children At High Anaesthetic Risk At The Time Of Primary Palatoplasty

Closure of the palate is an operation with a higher risk of postoperative hypoxaemia than other plastic surgical procedures. An increase in anaesthetic complications was noticed among our children with a cleft palate who were operated on with a palatoplasty, and this was further investigated. The records of 154 patients operated on between 1979 and 1996 were eligible for the study. A total of 128 had isolated cleft palate (ICP), 19 had Pierre Robin syndrome (PRS), and seven had other identified syndromes (IS). The results showed that the risk of anaesthetic complications was four times greater when the operation was done when the child was less than 1 year old, and there was a sixfold increase when a more elaborate velopharyngoplasty technique was used. Children with Pierre Robin syndrome were further classified according to the degree of neonatal difficulties. The 12 children with most severe problems were at increased risk. When the diagnostic criteria as well as the type of operation were taken into account the incidence of anaesthetic complications was 7/11, which was the highest risk encountered in the present study. When the first operation on the palate in children with Pierre Robin syndrome is planned, it should be based on a classification of neonatal problems and an investigation of their clinical condition. In children at risk the palatoplasty procedure should be postponed until the age of 12-18 months.Closure of the palate is an operation with a higher risk of postoperative hypoxaemia than other plastic surgical procedures. An increase in anaesthetic complications was noticed among our children with a cleft palate who were operated on with a palatoplasty, and this was further investigated. The records of 154 patients operated on between 1979 and 1996 were eligible for the study. A total of 128 had isolated cleft palate (ICP), 19 had Pierre Robin syndrome (PRS), and seven had other identified syndromes (IS). The results showed that the risk of anaesthetic complications was four times greater when the operation was done when the child was less than 1 year old, and there was a sixfold increase when a more elaborate velopharyngoplasty technique was used. Children with Pierre Robin syndrome were further classified according to the degree of neonatal difficulties. The 12 children with most severe problems were at increased risk. When the diagnostic criteria as well as the type of operation were taken into account the incidence of anaesthetic complications was 7/11, which was the highest risk encountered in the present study. When the first operation on the palate in children with Pierre Robin syndrome is planned, it should be based on a classification of neonatal problems and an investigation of their clinical condition. In children at risk the palatoplasty procedure should be postponed until the age of 12-18 months.

The Effect of Growth Factors and Synovial Fluid on Chondrogenesis in Perichondrium

Reconstruction of cartilage with perichondrium depends on the chondrogenic property of the perichondrial fibrocytes. The present investigation concerns the conditions for the differentiation of fibrocytes into chondrocytes both in vivo and in vitro. For the in vivo studies specimens of rib and auricular perichondrium from adult rabbits were wrapped round silicon rods which were enclosed in dialysis bags. One was placed in the suprapatellar pouch of the knee joint and one was placed intraperitoneally in each rabbit. After two months the bags were extracted, the perichondrium prepared for microscopic examination, and the chondrogenesis evaluated. In vitro the perichondrium was divided into small pieces and incubated with tissue culture medium. The medium was supplemented with fetal calf serum, together with epidermal growth factor, platelet derived growth factor, synovial fluid, or with human serum albumin (control group). After three weeks the explants were prepared for microscopy. Chondrogenesis was judged by the degree of cellular enlargement, capsule formation, deposition of matrix, and activation of the outer fibrocytic layer. In vivo, good cartilage development was found in all specimens placed in the knee joint but, in those placed intraperitoneally, little if any chondrogenesis was seen. In vitro profound differentiation occurred in all cultures supplemented with epidermal growth factor and platelet derived growth factor. An equivalent differentiation was found in perichondrium that had been incubated with synovial fluid. We conclude that the differentiation of perichondrial fibrocytes is initiated in vitro by growth factors. In addition, we have shown that synovial fluid contains factors that promote and enhance the development of cartilage from perichondrium.

Intravelar veloplasty reinforced with palatopharyngeal muscle: a review of a 10-year consecutive series.

We describe a technique by which the intravelar veloplasty was reinforced by including the superior part of posterior pillars and their palatopharyngeal muscle sheet in patients with cleft lip and palate. Our aim was to increase the functional length and strength of the velum and to reduce nasal emission and the need for pharyngeal flaps. Since 1990 more than 200 patients have been operated on in this way at Uppsala University Hospital. This is a retrospective follow-up of 162 consecutive patients operated on by two senior surgeons between 1990 and 2000. We describe the technique, timing, and operative observations as well as the outcome and the need for revision of the palatoplasty in some cases because of complications. To facilitate speech, 21 patients born between 1990 and 1997 (16%) were provided with a pharyngeal flap.

Expression of Platelet-Derived Growth Factor β Receptor in Chondrogenesis of Perichondrial Transplants

An experimental study was done in two rabbits to establish whether the early stages of cartilage generation involves stimulation via the platelet-derived growth factor beta receptor (PDGFR-beta). Rib perichondrium was dissected off and transplanted to the knee joint. The perichondrial grafts were removed for microscopic investigation at day 0 and day 6 and kept frozen until analysed by immunohistochemistry and in situ hybridisation for the presence of PDGF beta receptor protein and mRNA, respectively. Samples from day 0 showed sparse cells with a positive immunohistochemical reaction. In samples from day 6 there were signs of perichondrial proliferation and chondroid maturation and a more widespread immunohistochemical staining reaction could be seen mainly on proliferating perichondrial cells, but also on some chondrocytes. In situ hybridisation confirmed the expression of PDGF beta receptor mRNA in the same areas of serial sections. These findings may indicate that PDGF beta receptor activity is part of the early response after autotransplantation of perichondrium.

Time course of macromolecule synthesis in human lymphocyte cultures stimulated by antilymphocyte globulin and phytohemagglutinin.

The macromolecule synthesis induced by antilymphocyte globulin (ALG) and phytohemagglutinin (PHA) was studied in human lymphocyte cultures. The preparation and resulting characteristics of a rabbit an

Skoog Primary Periosteoplasty versus Secondary Alveolar Bone Grafting in Unilateral Cleft Lip and Alveolus: Long-term Effects on Alveolar Bone Formation and Maxillary Growth

Background: Clefts involving the alveolus are treated using one of two strategies: primary periosteoplasty at the time of lip repair or secondary alveolar bone grafting at mixed dentition. Most teams favor secondary alveolar bone grafting because of its high success rate, and concerns have been raised that primary periosteoplasty may interfere with maxillary growth. However, primary periosteoplasty may obviate the need for future bone grafting and is still practiced in some centers. Few studies compare the long-term outcomes of these two strategies. Methods: Fifty-seven consecutive patients born with unilateral cleft lip and alveolus were studied retrospectively. All patients underwent primary lip repair using Skoog’s method; 28 patients underwent primary periosteoplasty at the time of lip repair and the remaining 29 underwent secondary alveolar bone grafting at mixed dentition. Occlusal radiographs obtained at ages 10 and 16 years were analyzed for alveolar bone height. Cephalometric analysis assessed growth at ages 5, 10, and 18 years. Results: Seventeen of 28 patients treated using primary periosteoplasty required later secondary bone grafting, and the bone height at age 16 years was lower in the primary periosteoplasty group (p < 0.0001). There was a more pronounced decrease in maxillary protrusion from ages 5 to 10 years in the primary periosteoplasty group (p < 0.03). However, at age 18 there was no significant difference in maxillary growth between the two groups. Conclusion: Primary periosteoplasty did not seem to inhibit long-term maxillary growth but was ineffective as a method of reconstructing the alveolar cleft. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Early Release of Interalveolar Synechiae Under General Anesthesia Through Fiberscopic Nasal Intubation

Abstract This article presents a treatment strategy for early release of interalveolar synechiae, aiming to facilitate early oral feeding and prevent temporomandibular joint ankylosis. The treatment results of 2 patients with van der Woude syndrome were retrospectively studied. Both patients underwent early surgical release of interalveolar synechiae under general anesthesia through fiberscopic nasal intubation. The 2 patients were treated at the ages of 6 and 14 days, respectively. The interincisival distances increased from 5 and 6 mm preoperatively to 11 and 10 mm immediately after surgery. This was increased further to 25 and 20 mm at long-term follow-up (6 and 24 months). In conclusion, synechiae between the upper and lower jaws can be safely treated at a very early age under general anesthesia with fiberscopic nasotracheal intubation. The purpose of early intervention in these cases is to facilitate oral feeding and prevent temporomandibular joint ankylosis.

Reduction mammaplasty and the use of dextran against thromboembolism.

A retrospective study was conducted on 98 consecutive patients who had reduction mammaplasty done by different techniques during 1995, to find out the effect of dextran 70 on operative blood loss and postoperative complications. The most common procedure was reduction with a laterally based flap ( n = 67) followed by a Lejour vertical mammaplasty ( n = 15) and a medially based flap ( n = 12). Four had other operations. Dextran 70 was given peroperatively to 64 patients and their median (range) blood loss was 350 (30-1000) ml and drainage volume 80 (10-465) ml. In 33 patients not treated with dextran 70 the median (range) blood loss was 200 (25- 650) ml and the drainage volume 40 (0-115) ml. Ten patients developed major complications and 16 minor complications and there was no difference in the complication rate between those given dextran 70 (18/64, 28%) and those who were not (8/33, 24%), p = 0.8. Complications were no more common in smokers, overweight patients or those whose breasts were reduced by more than 1500 g, but there was a tendency to find more complications after the Lejour vertical mammaplasty. In conclusion, the study shows that patients undergoing mammaplasty and given Dextran 70 have an acceptable blood loss and drainage. In patients with a high risk of developing thromboembolism there is a need for a prophylactic agent and this study shows that dextran 70 may safely be used during reduction mammaplasty.