Surgical suturing of articular cartilage induces osteoarthritis-like changes

INTRODUCTION: In clinical tissue-engineering-based approaches to articular cartilage repair, various types of flap are frequently used to retain an implanted construct within the defect, and they are usually affixed by suturing. We hypothesize that the suturing of articular cartilage is associated with a loss of chondrocytes from, and osteoarthritis-like changes within, the perisutural area. MATERIALS AND METHODS: We established a large, partial-thickness defect model in the femoral groove of adult goats. The defects were filled with bovine fibrinogen to support a devitalized flap of autologous synovial tissue, which was sutured to the surrounding articular cartilage with single, interrupted stitches. The perisutural and control regions were analyzed histologically, histochemically and histomorphometrically shortly after surgery and 3 weeks later. RESULTS: Compared to control regions, chondrocytes were lost from the perisutural area even during the first few hours of surgery. During the ensuing 3 weeks, the numerical density of cells in the perisutural area decreased significantly. The cell losses were associated with a loss of proteoglycans from the extracellular matrix. Shortly after surgery, fissures were observed within the walls of the suture channels. By the third week, their surface density had increased significantly and they were filled with avascular mesenchymal tissue. CONCLUSIONS: The suturing of articular cartilage induces severe local damage, which is progressive and reminiscent of that associated with the early stages of osteoarthritis. This damage could be most readily circumvented by adopting an alternative mode of flap affixation, such as gluing with a biological adhesive.

A systematic review assessing soft tissue augmentation techniques

AIM: The aim of the present review was to systematically assess the dental literature in terms of soft tissue grafting techniques. The focused question was: is one method superior over others for augmentation and stability of the augmented soft tissue in terms of increasing the width of keratinized tissue (part 1) and gain in soft tissue volume (part 2). METHODS: A Medline search was performed for human studies focusing on augmentation of keratinized tissue and/or soft tissue volume, and complemented by additional hand searching. Relevant studies were identified and statistical results were reported for meta-analyses including the test minus control weighted mean differences with 95% confidence intervals, the I-squared statistic for tests of heterogeneity, and the number of significant studies. RESULTS: Twenty-five (part 1) and three (part 2) studies met the inclusion criteria; 14 studies (part 1) were eligible for comparison using meta-analyses. An apically positioned flap/vestibuloplasty (APF/V) procedure resulted in a statistically significantly greater gain in keratinized tissue than untreated controls. APF/V plus autogenous tissue revealed statistically significantly more attached gingiva compared with untreated controls and a borderline statistical significance compared with APF/V plus allogenic tissue. Statistically significantly more shrinkage was observed for the APF/V plus allogenic graft compared with the APF/V plus autogenous tissue. Patient-centered outcomes did not reveal any of the treatment methods to be superior regarding postoperative complications. The three studies reporting on soft tissue volume augmentation could not be compared due to lack of homogeneity. The use of subepithelial connective tissue grafts (SCTGs) resulted in statistically significantly more soft tissue volume gain compared with free gingival grafts (FGGs). CONCLUSIONS: APF/V is a successful treatment concept to increase the width of keratinized tissue or attached gingiva around teeth. The addition of autogenous tissue statistically significantly increases the width of attached gingiva. For soft tissue volume augmentation, only limited data are available favoring SCTGs over FGG.

Nasolabial esthetics in children with complete unilateral cleft lip and palate after 1- versus 3-stage treatment protocols

PURPOSE: Facial esthetics play an important role in social interactions. However, children with a repaired complete unilateral cleft lip and palate usually show some disfigurement of the nasolabial area. To date, few studies have assessed the nasolabial appearance after different treatment protocols. The aim of the present study was to compare the nasolabial esthetics after 1- and 3-stage treatment protocols. MATERIALS AND METHODS: Four components of the nasolabial appearance (nasal form, nasal deviation, mucocutaneous junction, and profile view) were assessed by 4 raters in 108 consecutively treated children who had undergone either 1-stage closure (Warsaw group, 41 boys and 19 girls, mean age 10.8 years, SD 2.0) or 3-stage (Nijmegen group, 30 boys and 18 girls, mean age 8.9 years, SD 0.7). A 5-grade esthetic index of Asher-McDade was used, in which grade 1 indicates the most esthetic and grade 5 the least esthetic outcome. RESULTS: The nasal form was judged the least esthetic in both groups and graded 3.1 (SD 1.1) and 3.2 (SD 1.1). The nasal deviation, mucocutaneous junction, and profile view were scored from 2.1 (SD 0.8) to 2.3 (SD 1.0) in both groups. The treatment outcome after the Warsaw and Nijmegen protocols was comparable. Neither overall nor any of the 4 components of the nasolabial appearance showed intercenter differences (P > .1). CONCLUSIONS: The nasolabial appearance after the Warsaw (1-stage) and Nijmegen (3-stage) protocols was comparable. The technique of lip repair (triangular flap in Warsaw and Millard rotation advancement in Nijmegen) gave comparable results for the esthetics of the nasolabial area.

Soft tissues healing at immediate transmucosal implants placed into molar extraction sites with buccal self-contained dehiscences. A 12-month controlled clinical trial

AIM: To assess soft tissues healing at immediate transmucosal implants placed into molar extraction sites with buccal self-contained dehiscences. MATERIAL AND METHODS: For this 12-month controlled clinical trial, 15 subjects received immediate transmucosal tapered-effect (TE) implants placed in molar extraction sockets displaying a buccal bone dehiscence (test sites) with a height and a width of > or =3 mm, respectively. Peri-implant marginal defects were treated according to the principles of Guided Bone Regeneration (GBR) by means of deproteinized bovine bone mineral particles in conjunction with a bioresorbable collagen membrane. Fifteen subjects received implants in healed molar sites (control sites) with intact buccal alveolar walls following tooth extraction. In total, 30 TE implants with an endosseous diameter of 4.8 mm and a shoulder diameter of 6.5 mm were used. Flaps were repositioned and sutured, allowing non-submerged, transmucosal soft tissues healing. At the 12-month follow-up, pocket probing depths (PPD) and clinical attachment levels (CAL) were compared between implants placed in the test and the control sites, respectively. RESULTS: All subjects completed the 12-month follow-up period. All implants healed uneventfully, yielding a survival rate of 100%. After 12 months, statistically significantly higher (P<0.05) PPD and CAL values were recorded around implants placed in the test sites compared with those placed in the control sites. CONCLUSIONS: The findings of this controlled clinical trial showed that healing following immediate transmucosal implant installation in molar extraction sites with wide and shallow buccal dehiscences yielded less favorable outcomes compared with those of implants placed in healed sites, and resulted in lack of 'complete' osseointegration.

Hemoglobin vesicles improve wound healing and tissue survival in critically ischemic skin in mice

Local hypoxia, as due to trauma, surgery, or arterial occlusive disease, may severely jeopardize the survival of the affected tissue and its wound-healing capacity. Initially developed to replace blood transfusions, artificial oxygen carriers have emerged as oxygen therapeutics in such conditions. The aim of this study was to target primary wound healing and survival in critically ischemic skin by the systemic application of left-shifted liposomal hemoglobin vesicles (HbVs). This was tested in bilateral, cranially based dorsal skin flaps in mice treated with a HbV solution with an oxygen affinity that was increased to a P(50) (partial oxygen tension at which the hemoglobin becomes 50% saturated with oxygen) of 9 mmHg. Twenty percent of the total blood volume of the HbV solution was injected immediately and 24 h after surgery. On the first postoperative day, oxygen saturation in the critically ischemic middle flap portions was increased from 23% (untreated control) to 39% in the HbV-treated animals (P < 0.05). Six days postoperatively, flap tissue survival was increased from 33% (control) to 57% (P < 0.01) and primary healing of the ischemic wound margins from 6.6 to 12.7 mm (P < 0.05) after HbV injection. In addition, higher capillary counts and endothelial nitric oxide synthase expression (both P < 0.01) were found in the immunostained flap tissue. We conclude that left-shifted HbVs may ameliorate the survival and primary wound healing in critically ischemic skin, possibly mediated by endothelial nitric oxide synthase-induced neovascularization.

PET-CT-guided interventions in the management of FDG-positive lesions in patients suffering from solid malignancies: initial experiences

Positron emission tomography-computed tomography (PET-CT) has gained widespread acceptance as a staging investigation in the diagnostic workup of malignant tumours and may be used to visualize metabolic changes before the evolution of morphological changes. To make histology of PET findings without distinctive structural changes available for treatment decisions, we developed a protocol for multimodal image-guided interventions using an integrated PET-CT machine. We report our first experience in 12 patients admitted for staging and restaging of breast cancer, non-small cell lung cancer, cervical cancer, soft tissue sarcoma, and osteosarcoma. Patients were repositioned according to the findings in PET-CT and intervention was planned based on a subsequent single-bed PET-CT acquisition of the region concerned. The needle was introduced under CT guidance in a step-by-step technique and correct needle position in the centre of the FDG avid lesion was assured by repetition of a single-bed PET-CT acquisition before sampling. The metabolically active part of lesions was accurately targeted in all patients and representative samples were obtained in 92%. No major adverse effects occurred. We conclude that PET-CT guidance for interventions is feasible and may be promising to optimize the diagnostic yield of CT-guided interventions and to make metabolically active lesions without morphological correlate accessible to percutaneous interventions.

Hormographiella aspergillata keratomycosis in a dog

A 4-year-old, female, Border Collie was presented to the University of Bern Veterinary Teaching Hospital, because of a corneal lesion of 10 days duration. The axial cornea presented a whitish fluorescein-positive plaque with irregular margins. A diagnosis of keratomycosis was made based on cytology. Medical therapy with local broad-spectrum antibiotic and fluconazole was instituted. After 1 week of treatment, the improvement was deemed unsatisfactory. Therefore, a lamellar keratectomy and conjunctival pedicle flap were performed. After surgery, the cornea healed uneventfully. Histology confirmed the diagnosis of keratomycosis. The fungus could not be grown in culture and a precise etiological diagnosis could only be obtained with genetic identification of the fungus. A PCR technique was used to amplify the fungal genome from the cornea. Hormographiella aspergillata, the asexual reproductive form of the basidiomycete Coprinopsis cinerea, was identified. As advised in human medicine, we encourage the use of this molecular technique to obtain an early species diagnosis, allowing targeted medical therapy.

Phylogeny of horse chromosome 5q in the genus Equus and centromere repositioning

Horses, asses and zebras belong to the genus Equus and are the only extant species of the family Equidae in the order Perissodactyla. In a previous work we demonstrated that a key factor in the rapid karyotypic evolution of this genus was evolutionary centromere repositioning, that is, the shift of the centromeric function to a new position without alteration of the order of markers along the chromosome. In search of previously undiscovered evolutionarily new centromeres, we traced the phylogeny of horse chromosome 5, analyzing the order of BAC markers, derived from a horse genomic library, in 7 Equus species (E. caballus, E. hemionus onager, E. kiang, E. asinus, E. grevyi, E. burchelli and E. zebra hartmannae). This analysis showed that repositioned centromeres are present in E. asinus (domestic donkey, EAS) chromosome 16 and in E. burchelli (Burchell's zebra, EBU) chromosome 17, confirming that centromere repositioning is a strikingly frequent phenomenon in this genus. The observation that the neocentromeres in EAS16 and EBU17 are in the same chromosomal position suggests that they may derive from the same event and therefore, E. asinus and E. burchelli may be more closely related than previously proposed; alternatively, 2 centromere repositioning events, involving the same chromosomal region, may have occurred independently in different lineages, pointing to the possible existence of hot spots for neocentromere formation. Our comparative analysis also showed that, while E. caballus chromosome 5 seems to represent the ancestral configuration, centric fission followed by independent fusion events gave rise to 3 different submetacentric chromosomes in other Equus lineages.

Drought Stress alters Solute Allocation in Broadleaf Dock (Rumex obtusifolius)

According to climate models, drier summers must be expected more frequently in Central Europe during the next decades, which may influence plant performance and competition in grassland. The overall source–sink relations in plants, especially allocation of solutes to above- and below-ground parts, may be affected by drought. To investigate solute export from a given leaf of broadleaf dock, a solution containing 57Co and 65Zn was introduced through a leaf flap. The export from this leaf was detected by analysing radionuclide contents in various plant parts. Less label was allocated to new leaves and more to roots under drought. The observed alterations of source–sink relations in broadleaf dock were reversible during a subsequent short period of rewatering. These findings suggest an increased resource allocation to roots under drought improving the functionality of the plants.

Absorbable collagen membranes for periodontal regeneration: a systematic review

Guided tissue regeneration (GTR) with bioabsorbable collagen membranes (CM) is commonly used for the treatment of periodontal defects. The objective of this systematic review of randomized clinical trials was to assess the clinical efficacy of GTR procedures with CM, with or without bone substitutes, in periodontal infrabony defects compared with that of open flap debridement (OFD) alone. Primary outcomes were tooth loss and gain in clinical attachment level (CAL). Screening of records, data extraction, and risk-of-bias assessments were performed by two reviewers. Weighted mean differences were estimated by random effects meta-analysis. We included 21 reports on 17 trials. Risk of bias was generally high. No data were available for the primary outcome tooth loss. The summary treatment effect for change in CAL for GTR with CM compared with OFD was 1.58 mm (95% CI, 1.27 to 1.88). Despite large between-trial heterogeneity (I2 = 75%, p < .001), all trials favored GTR over OFD. No differences in treatment effects were detected between trials of GTR with CM alone and trials of GTR with CM in combination with bone substitutes (p for interaction, .31). GTR with CM, with or without substitutes, may result in improved clinical outcomes compared with those achieved with OFD alone. Our findings support GTR with CM for the treatment of infrabony periodontal defects.

Treatment of multiple adjacent Miller class I and II gingival recessions with a Modified Coronally Advanced Tunnel (MCAT) technique and a collagen matrix or palatal connective tissue graft: a randomized, controlled clinical trial

BACKGROUND A newly developed collagen matrix (CM) of porcine origin has been shown to represent a potential alternative to palatal connective tissue grafts (CTG) for the treatment of single Miller Class I and II gingival recessions when used in conjunction with a coronally advanced flap (CAF). However, at present it remains unknown to what extent CM may represent a valuable alternative to CTG in the treatment of Miller Class I and II multiple adjacent gingival recessions (MAGR). The aim of this study was to compare the clinical outcomes following treatment of Miller Class I and II MAGR using the modified coronally advanced tunnel technique (MCAT) in conjunction with either CM or CTG. METHODS Twenty-two patients with a total of 156 Miller Class I and II gingival recessions were included in this study. Recessions were randomly treated according to a split-mouth design by means of MCAT + CM (test) or MCAT + CTG (control). The following measurements were recorded at baseline (i.e. prior to surgery) and at 12 months: Gingival Recession Depth (GRD), Probing Pocket Depth (PD), Clinical Attachment Level (CAL), Keratinized Tissue Width (KTW), Gingival Recession Width (GRW) and Gingival Thickness (GT). GT was measured 3-mm apical to the gingival margin. Patient acceptance was recorded using a Visual Analogue Scale (VAS). The primary outcome variable was Complete Root Coverage (CRC), secondary outcomes were Mean Root Coverage (MRC), change in KTW, GT, patient acceptance and duration of surgery. RESULTS Healing was uneventful in both groups. No adverse reactions at any of the sites were observed. At 12 months, both treatments resulted in statistically significant improvements of CRC, MRC, KTW and GT compared with baseline (p < 0.05). CRC was found at 42% of test sites and at 85% of control sites respectively (p < 0.05). MRC measured 71 ± 21% mm at test sites versus 90 ± 18% mm at control sites (p < 0.05). Mean KTW measured 2.4 ± 0.7 mm at test sites versus 2.7 ± 0.8 mm at control sites (p > 0.05). At test sites, GT values changed from 0.8 ± 0.2 to 1.0 ± 0.3 mm, and at control sites from 0.8 ± 0.3 to 1.3 ± 0.4 mm (p < 0.05). Duration of surgery and patient morbidity was statistically significantly lower in the test compared with the control group respectively (p < 0.05). CONCLUSIONS The present findings indicate that the use of CM may represent an alternative to CTG by reducing surgical time and patient morbidity, but yielded lower CRC than CTG in the treatment of Miller Class I and II MAGR when used in conjunction with MCAT.

Histological evaluation of human intrabony periodontal defects treated with an unsintered nanocrystalline hydroxyapatite paste

OBJECTIVES The aim of the study was to clinically and histologically evaluate the healing of human intrabony defects treated with open flap surgery (OFD) and application of a new, resorbable, fully synthetic, unsintered, nanocrystalline, phase-pure hydroxyapatite (nano-HA). MATERIALS AND METHODS Six patients, each of them displaying very advanced intrabony defects around teeth scheduled for extraction due to advanced chronic periodontitis and further prosthodontic considerations, were included in the study. Following local anaesthesia, mucoperiosteal flaps were reflected; the granulation tissue was removed, and the roots were meticulously debrided by hand and ultrasonic instruments. A notch was placed at the most apical extent of the calculus present on the root surface or at the most apical part of the defect (if no calculus was present) in order to serve as a reference for the histological evaluation. Following defect fill with nano-HA, the flaps were sutured by means of mattress sutures to allow primary intention healing. At 7 months after regenerative surgery, the teeth were extracted together with some of their surrounding soft and hard tissues and processed for histological analysis. RESULTS The postoperative healing was uneventful in all cases. At 7 months following surgery, mean PPD reduction and mean CAL gain measured 4.0 ± 0.8 and 2.5 ± 0.8 mm, respectively. The histological analysis revealed a healing predominantly characterized by epithelial downgrowth. Limited formation of new cementum with inserting connective tissue fibers and bone regeneration occurred in three out of the six biopsies (i.e. 0-0.86 and 0-1.33 mm, respectively). Complete resorption of the nano-HA was found in four out of the six biopsies. A few remnants of the graft particles (either surrounded by newly formed mineralized tissue or encapsulated in connective tissue) were found in two out of the six biopsies. CONCLUSION Within their limits, the present results indicate that nano-HA has limited potential to promote periodontal regeneration in human intrabony defects. CLINICAL RELEVANCE The clinical outcomes obtained following surgery with OFD + nano-HA may not reflect true periodontal regeneration.

Patients with oral tumors. Part 1: Prosthetic rehabilitation following tumor resection. Resection prosthetics: surgery, implants and prosthetic treatment

The present study reports on the surgical and prosthodontic rehabilitation of 46 patients, 31 male and 15 female, after resection of oral tumors. The treatment was carried out from 2004 to 2007 at the Department of Prosthodontics, University of Bern, with a follow-up time of 3 to 6 years. The average age at diagnosis was 54 years. 76% of all tumors were squamous cell carcinoma, followed by adenocarcinoma. Resection of the tumors including soft and/or hard tissues was performed in all patients. 80% of them additionally underwent radiotherapy and 40% chemotherapy. A full block resection of the mandible was perfomed in 23 patients, and in 10 patients, the tumor resection resulted in an oronasal communication. 29 patients underwent grafting procedures, mostly consisting of a free fibula flap transplant. To enhance the prosthetic treatment outcome and improve the prosthesis stability, a total of 114 implants were placed. However, 14 implants were not loaded because they failed during the healing period or the patient could not complete the final treatment with the prostheses. The survival rate of the implants reached 84.2% after 4 to 5 years. Many patients were only partially dentate before the tumors were detected, and further teeth had to be extracted in the course of the tumor therapy. Altogether, 31 jaws became or remained edentulous. Implants provide stability and may facilitate the adaptation to the denture, but their survival rate was compromised. Mostly, patients were fitted with removable prostheses with obturators in the maxilla and implant-supported complete dentures with bars in the mandible. Although sequelae of tumor resection are similar in many patients, the individual intermaxillary relations, facial morphology and functional capacity vary significantly. Thus, individual management is required for prosthetic rehabilitation.

The role of intercostal nerve preservation in pain control after thoracotomy

OBJECTIVES Pain control after thoracotomy is an important issue that affects the outcome in thoracic surgery. Intercostal nerve preservation (ICNP) has increased interest in the outcomes of conventional thoracotomy. The current study critically evaluates the role of preservation of the intercostal nerve in early and late pain control and its benefit in patients undergoing thoracotomy. METHODS Data obtained prospectively between January 2006 and December 2010 by a study colleague at our division of General Thoracic Surgery were retrospectively analysed. There were 491 patients who underwent thoracotomy. Eighty-one patients were excluded from the study due to incompatible data. Patients were divided into two groups according to the intercostal nerve state: Group I consisted of patients with ICNP and Group II consisted of patients with intercostal nerve sacrifice. RESULTS Group I consisted of 288 patients [206 male (71%), P < 0.001, mean age 66 years]. Group II consisted of 122 patients [79 male (64%), P = 0.001, mean age 66 years]. There was less use of opiate in Group I (P = 0.019). Early mobilization of the patients was significantly higher in Group I (P = 0.031). The rate of pneumonia and re-admission to the intensive care unit was higher in Group II (P = 0.017 and 0.023, respectively). The rate of pain-free patients at discharge was significantly higher in Group I (P = 0.028). A 2-week follow-up after hospital discharge showed parasternal hypoesthesia to be more in Group II (P = 0.034). Significant patient contentment in Group I was noticed (P = 0.014). Chronic post-thoracotomy pain (CPTP) was higher in Group II (P = 0.016). CONCLUSIONS ICNP without harvesting an intercostal muscle flap achieves excellent outcomes in controlling acute post-thoracotomy pain and CPTP. ICNP is an effective, simple method to perform, and it should be considered as standard in performing thoracotomy.

Botulinum toxin A and B raise blood flow and increase survival of critically ischemic skin flaps

BACKGROUND Botulinum toxin (BTX) A and B are commonly used for aesthetic indications and in neuromuscular disorders. New concepts seek to prove efficacy of BTX for critical tissue perfusion. Our aim was to evaluate BTX A and B in a mouse model of critical flap ischemia for preoperative and intraoperative application. METHODS BTX A and B were applied on the vascular pedicle of an axial pattern flap in mice preoperatively or intraoperatively. Blood flow, tissue oxygenation, tissue metabolism, flap necrosis rate, apoptosis assay, and RhoA and eNOS expression were endpoints. RESULTS Blood-flow measurements 1 d after the flap operation revealed a significant reduction to 53% in the control group, while flow was maintained or increased in all BTX groups (103%-129%). Over 5 d all BTX groups showed significant increase in blood flow to 166-187% (P < 0.01). Microdialysis revealed an increase of glucose and reduced lactate/pyruvate ratio and glycerol levels in the flap tissue of all BTX groups. This resulted in significantly improved tissue survival in all BTX groups compared with the control group (62% ± 10%; all P < 0.01): BTX A preconditioning (84% ± 5%), BTX A application intraoperatively (88% ± 4%), BTX B preconditioning (91% ± 4%), and intraoperative BTX B treatment (92% ± 5%). This was confirmed by TUNEL assay. Immunofluorescence demonstrated RhoA and eNOS expression in BTX groups. All BTX applications were similarly effective, despite pharmacologic dissimilarities and different timing. CONCLUSIONS In conclusion, we were able to show on a vascular, tissue, cell, and molecular level that BTX injection to the feeding arteries supports flap survival through ameliorated blood flow and oxygen delivery.