Application of Polydioxanone Sutures in the Nuss Procedure.

BACKGROUND/PURPOSE: The Nuss procedure is the most common surgical repair for pectus excavatum (PE). Surgical steel wires are used in some modifications of the Nuss procedure to attach one or both ends of a support bar to the ribs. During follow-up, wire breakage was found in some cases. Patients with wire breakage may undergo prolonged bar removal surgery and may be exposed to excessive radiation.In this study, we had a series of patients who received polydioxanone suture (PDS) fixations instead of steel wires. This retrospective study was conducted to explore the differences between these two fixation materials in the incidence of related complications and efficacies. Furthermore, we attempted to observe whether the two materials lead to similar surgical efficacy in the Nuss procedure, whether they have divergent effects on the bar removal surgery, and whether PDS can reduce the risks due to steel wire breakage as expected. METHODS: We retrospectively studied PDS and surgical steel wires as fixation materials for the Nuss procedure in children with congenital PE and reviewed the outcomes and complications. A total of 75 children who had undergone Nuss procedure repairs and bar removals from January 2013 to December 2019 were recruited to participate in this study. They were divided into three groups: the PDS group, the unbroken wire (UBW) group, and the broken wire (BW) group, according to the fixation materials and whether the wires had broken or not. Moreover, we selected the duration of operation (DO), intraoperative blood loss (BL), bar displacement (BD), postoperative pain score (PPS), and incision infection as the risk indicators and the postrepair Haller index (HI) as the effectiveness indicator. These indicators were statistically compared to determine whether there were differences among the three groups. RESULTS: One BD occurred in the PDS and BW groups while none took place in the UBW group. No incision infection was found in any of the groups. The PDS group had the shortest DO, while the DO in the UBW group was shorter than that in the BW group (p < 0.05). BL in the PDS group was less than that in the other two groups (p < 0.05). Additionally, no difference was observed in BL between the BW and UBW groups (p > 0.05). The PPS of the PDS group was less than that of the BW group (p < 0.05), whereas no differences were found between the other two groups. No statistical difference emerged in HI among the groups (p > 0.05). CONCLUSION: PDS fixation results in a similar repair outcome and shows certain advantages in the DO, BL, and PPS; also, PDSs are safe and effective in the Nuss procedure. LEVEL OF EVIDENCE: Level III.

Orbital floor fractures: epidemiology and outcomes of 1594 reconstructions.

OBJECTIVE: The aim of this study was to retrospectively review the midface and orbital floor fractures treated at our institution with regard to epidemiological aspects, surgical treatment options and postoperative complications and discuss this data with the current literature. STUDY DESIGN: One thousand five hundred and ninety-four patients with midface and orbital fractures treated at the Department of Oral, Cranio-Maxillofacial and Facial Plastic Surgery of the Goethe University Hospital in Frankfurt (Germany) between 2007 and 2017 were retrospectively reviewed. The patients were evaluated by age, gender, etiology, fracture pattern, defect size, surgical treatment and complications. RESULTS: The average patient age was 46.2 (± 20.8). Most fractures (37.5%) occurred in the age between 16 and 35. Seventy-two percent of patients were male while 28% were female. The most common cause of injury was physical assault (32.0%) followed by falls (30.8%) and traffic accidents (17.0%). The average orbital wall defect size was 297.9 mm2 (± 190.8 mm2). For orbital floor reconstruction polydioxanone sheets (0.15 mm 38.3%, 0.25 mm 36.2%, 0.5 mm 2.8%) were mainly used, followed by titanium meshes (11.5%). Reconstructions with the 0.15 mm polydioxanone sheets showed the least complications (p < 0.01, r = 0.15). Eighteen percent of patients who showed persistent symptoms and post-operative complications: 12.9% suffered from persistent hypoesthesia, 4.4% suffered from post-operative diplopia and 3.9% showed intra-orbital hematoma. CONCLUSION: Results of the clinical outcome in our patients show that 0.15 mm resorbable polydioxanone sheets leads to significantly less post-operative complications for orbital floor defects even for defects beyond the recommended 200 mm2.

Histological evaluation of cellular response to a multifilament electrospun suture for tendon repair.

BACKGROUND: Rotator cuff tendon repair in humans is a commonly performed procedure aimed at restoring the tendon-bone interface. Despite significant innovation of surgical techniques and suture anchor implants, only 60% of repairs heal successfully. One strategy to enhance repair is the use of bioactive sutures that provide the native tendon with biophysical cues for healing. We investigated the tissue response to a multifilament electrospun polydioxanone (PDO) suture in a sheep tendon injury model characterised by a natural history of failure of healing. METHODOLOGY AND RESULTS: Eight skeletally mature English Mule sheep underwent repair with electrospun sutures. Monofilament sutures were used as a control. Three months after surgery, all tendon repairs healed, without systemic features of inflammation, signs of tumour or infection at necropsy. A mild local inflammatory reaction was seen. On histology the electrospun sutures were densely infiltrated with predominantly tendon fibroblast-like cells. In comparison, no cellular infiltration was observed in the control suture. Neovascularisation was observed within the electrospun suture, whilst none was seen in the control. Foreign body giant cells were rarely seen with either sutures. CONCLUSION: This study demonstrates that a tissue response can be induced in tendon with a multifilament electrospun suture with no safety concerns.

Comparative effects of various absorbable threads in a rat model.

BACKGROUND: Conventional procedures including botulinum toxin and filler injections have their limitations in improving deep wrinkles and decreasing tissue laxity, and possess the propensity for vascular accidents. Absorbable thread is a recently commercialized field, but there is little evidence on comparative superiority. OBJECTIVES: We observed the effects of polydiaxanone (PDO) threads with different number of strands in relation to collagen production and histopathology in a rat model. MATERIALS AND METHODS: Dorsal skin of rat was divided into five different compartments and four different PDO threads and monofilament poly-lactic acid (PLA) thread were inserted. Tissue samples were obtained at week 1, 2, and 12 after the procedure for histopathologic review and real-time PCR for quantification of collagen. RESULTS: Multiple PDO filaments produced more collagen at 2 weeks. Single-stranded PLA thread insertion resulted in more Col1α1 levels than the double PDO thread and also showed the most Col1α3 production at week 2. The amount of collagen showed a sharp decline at week 12. Histologic evaluation showed retained threads surrounded by fibrous capsule-like structure at week 12. CONCLUSION: We were able to observe more collagen production in multiple stranded PDO threads compared to a single strand and that increasing number of threads leads to more collagen synthesis.

Evidencia clínica y microscópica de la degradación de hilos de dermosustentación de polidioxanona en presencia de ácido hialurónico: reporte de caso / Microscopic and clinical evidence of the degradation of polydioxanone lifting threads in the presence of hyaluronic acid: a case report

Se expone el caso de una paciente remitida por complicaciones posteriores a la implantación superficial en el tercio medio facial de hilos de polidioxanona espiculados. Presentaba edema, equimosis, palpación superficial del hilo y plicación dérmica. Para el tratamiento planteamos un novedoso protocolo de degradación clínica de hilos de polidioxanona, empleando ácido hialurónico inyectándolo en el área de su implantación. Se infiltró ácido hialurónico no reticulado en el trayecto a lo largo del recorrido del hilo. El seguimiento a los siete, 21 y 45 días evidenció disminución del edema, de los pliegues e irregularidades dérmicas por la tracción del hilo y atenuación de rítides secundarias. Una muestra del hilo en ácido hialurónico fue observado en campana de flujo laminar evidenciándose degradación a las 72 horas. Administrar ácido hialurónico fue efectivo para inducir la biodegradación clínica del hilo. La hipótesis derivada sugiere que el ácido hialurónico no reticulado es un poderoso catalizador de la degradación hidrolítica de la polidioxanona.

We present the case of a female patient with complications from superficial implantation of polydioxanone spiculated threads in the facial middle third. The manifestations were edema, ecchymosis, superficial palpation of the thread and skin plication. For the treatment we propose a novel protocol of clinical degradation of polydioxanone threads, using hyaluronic acid injecting it into the implantation area of the polydioxanone threads. Non-cross linked hyaluronic acid was infiltrated along the path of the thread. The follow-up at seven, 21 and 45 days showed decreased edema, folds and skin irregularities due to wire traction and attenuation of secondary rhytides. A sample of the thread in hyaluronic acid was observed in a laminar flow campaign evidencing degradation at 72 hours. Administering hyaluronic acid was effective in inducing clinical biodegradation of the thread suggesting that non-crosslinked hyaluronic acid is a powerful catalyst for the hydrolytic degradation of polydioxanone.

Tissue repair in neonatal and paediatric surgery: Analysis of infection in surgical implantation of synthetic resorbable biomaterials.

BACKGROUND: There has been increased interest in the use of biomaterials that resorb completely leaving only the patient's native tissue. Synthetic materials are advantageous for tissue repair because they are highly customisable. The infection rate of using resorbable natural materials in paediatric surgery has recently been outlined, but there has not yet been a review of the use of synthetic resorbable materials in paediatric surgery. OBJECTIVES: This systematic review analyses the risk of infection after implantation of fully resorbable synthetic biomaterials in paediatric cases. METHODS: The literature was searched from January 1970 to January 2018 (inclusive), specifically searching for paediatric cases (0-18 years old), use of synthetic resorbable materials and infection. RESULTS: The infection rate in 3573 cases of synthetic resorbable material implantation was 1.1% (41 cases). A Chi-squared test for independence found infection rate to vary among materials. Of the many biomaterials identified in this review, the highest infection rates were seen in Suprathel's use in burns injuries (12.1%). CONCLUSIONS: This review found a low infection rate in synthetic resorbable materials used in paediatric surgery, with particularly strong evidence for low infection risk in LactoSorb® use.

Complications of Polydioxanone Foil Use in Nasal Surgery: A Case Series.

Polydioxanone (PDS) foil is widely recognized as a septal cartilage replacement during rhinoplasties and is thought to be completely resorbable and biodegradable. Since its United States Food and Drug Administration approval in 2010, PDS foil has drawn significant enthusiasm and many surgeons consider it an ideal implantable biomaterial as reflected in numerous studies highlighting its benefits. However, scant literature exists highlighting relevant complications of PDS plates that may potentially lead to cavalier overuse. This descriptive case series assesses the outcomes of PDS foil usage in three patients seen for septoplasty at two independent institutions over the past 5 years. Our results demonstrate that PDS plate usage can lead to septal cartilage loss and resultant saddle nose deformity associated with prolonged postoperative edema and inflammation. To our knowledge, this is the largest case series of this reported phenomenon.

Investigation on the Cutaneous Change Induced by Face-Lifting Monodirectional Barbed Polydioxanone Thread.

BACKGROUND: Owing to its potentially greater mechanical force on the implanted tissue, barbed thread is frequently used in face-lifting procedures. However, the long-term durability thereof remains controversial. Moreover, reports on underlying histologic and molecular changes resulting from face-lifting procedures are scarce. OBJECTIVE: To evaluate histologic and molecular changes induced by absorbable, barbed face-lifting thread in an animal model. MATERIALS AND METHODS: Fragments of monofilament, monodirectionally barbed polydioxanone thread were implanted in dorsal skin from 12 guinea pigs. Tissue samples were harvested at 1, 3, and 7 months thereafter. Histopathologic analysis and quantification of Type 1 collagen and transforming growth factor beta 1 (TGF-ß1) levels were performed. RESULTS: Implantation of a single fragment induced fibrous capsule around the thread. Tissue reactions were strongest at 1 month after implantation, showing marked infiltration of inflammatory cells and fibroblasts, which gradually decreased. On molecular analysis, Type 1 collagen and TGF-ß1 levels were significantly increased, compared to normal skin, throughout the 7-month study period. CONCLUSION: Our results suggest that implantation of barbed thread induces strong anchorage to skin tissue. Quantitative analysis of collagen and its downstream signaling molecule TGF-ß supports the long-term durability of the thread. Therefore, the authors expect potential beneficial effect for rejuvenation on its clinical application.

Biodegradable airway stents in infants - Potential life-threatening pitfalls.

OBJECTIVE: The solution of severe tracheobronchial obstructions in early childhood means a great challenge. Biodegradable stents were intended to be a minimally invasive temporary solution which may decrease the number of interventions and limit the possible complications of stenting procedures. However, our first experiences have brought out a new, - especially in childhood - potentially life-threatening complication of this concept. METHODS: Five SX-ELLA biodegradable polydioxanone stents was applied in three patients because of severe tracheobronchial obstruction: congenital tracheomalacia (7 day-old), acquired tracheomalacia (10 month-old), and congenital trachea-bronchomalacia (10 month-old). RESULTS: The breathing of all children improved right after the procedure. We observed degradation of the stent from the 5th postoperative week which resulted in large intraluminar fragments causing significant airway obstruction: one patient died of severe pneumonia, the other baby required urgent bronchoscopy to remove the obstructing 'foreign body' from the trachea. In the third case repeated stent placements successfully maintained the tracheal lumen. CONCLUSIONS: Polydioxanone stents may offer an alternative to metallic or silastic stents for collapse or external compression of the trachea in children; however, large decaying fragments mean a potential risk especially in the small size pediatric airway. The fragmentation of the stent, which generally starts in the 4-6 postoperative weeks, may create large sharp pieces. These may be anchored to the mucosa and covered by crust leading to obstruction. As repeated interventions are required, we do not consider the application of biodegradable stents unambiguously advantageous.

Quantitative assessment and determinants of suture-holding capacity of human pancreas.

BACKGROUND: Hard pancreas is welcome by surgeons performing resective pancreatic surgery, because it is believed to offer better suture holding capacity (SHC), thus decreasing the risk for a postoperative leak. However, neither the actual SHC of pancreatic tissue in humans nor its determinants have been studied. METHODS: We directly measured SHC for polydioxanone 5-0 suture and tissue hardness at the pancreatic isthmus in 53 human pancreata using a dynamometer and a durometer. A histologic score based on fibrosis grade, fat content, pancreatic duct size, and signs of chronic pancreatitis was calculated for every sample. We tested the hypothesis that SHC of the pancreas was proportional to tissue hardness, and evaluated the role of different possible histomorphologic determinants of SHC. RESULTS: Suture-holding capacity correlated perfectly with tissue hardness (r = 0.98; P < 0.001; 95% confidence interval, 0.96-0.99). The histologic score showed a stronger correlation with both parameters than any single histologic parameter. The SHC of transductal sutures was significantly higher than that of pure transparenchymal sutures. The SHC and hardness were significantly lower in patients who developed a clinically relevant pancreatic fistula postoperatively. CONCLUSIONS: A mixture of histomorphologic features of human pancreas determines its tissue hardness and SHC. Involvement of the main pancreatic duct in the suture line appears to increase the mechanical strength of the pancreatic anastomosis.

Primary results of chest wall reconstruction with polydioxanone mesh on animals.

BACKGROUND: With the development of surgical techniques and biomedical material, increasing synthetic materials are applied to the chest wall reconstruction, such as autologous rib, muscle flap, bovine pericardium and sheet metal. AIM: To detect the safety and efficiency of synthetic material Polydioxanone (PDO) in chest wall reconstruction. MATERIALS AND METHODS: Healthy adult mongrel dogs operated with PDO, and then some clinical data were collected. RESULTS: Here we showed that PDO mesh could close down the function of chest wall defect, and PDO mesh could be degraded gradually and forms a fibrous layer with the surrounding tissues. Our data further demonstrated PDO mesh leads to slight lung adhesion with a small shrinkage. CONCLUSIONS: These findings thus provide the first evidence that the feasibility of PDO mesh in chest wall reconstruction in dogs.

Incisional hernia after abdominal closure with slowly absorbable versus fast absorbable, antibacterial-coated sutures.

BACKGROUND: Incisional hernia remains among the most common complications after midline incision of the abdominal wall. The role of the suture material used for abdominal wall closure remains controversial. To decrease bacterial adherence to surgical sutures, braided suture materials with antibacterial activity (Vicryl plus, Ethicon, Inc) were developed. This is the first study to analyze long-term results using an antibacterial-braided suture material for abdominal wall closure in a large clinical trial. METHODS: To analyze the effects of Triclosan-coated suture material (Vicryl plus) on the development of incisional hernia, we performed a 36-month follow-up of 1,018 patients who had a primary midline incision for elective abdominal surgery. In the first time period, a PDS II loop suture was used. In the second observation period, we used Vicryl plus. All variables were recorded prospectively in a database. The primary outcome was the number of incisional hernias. Risk factors for the development of incisional hernias were collected prospectively to compare the 2 groups. RESULTS: The overall incisional hernia rate in the 36-month follow-up period was 14.6%. Analyzing the influence of the suture material used on the development of incisional hernia, we did not find differences between the 2 groups (PDS II, 14%; Vicryl plus, 15.2%). In the multivariate analysis of possible factors in the study population, only body mass index (BMI) showed a significant influence on the development of incisional hernias. Despite the incidence of wound infections being less in the Vicryl plus group (6.1% vs 11.9%; P < .05), there were no difference in incidence of incisional hernia between the 2 groups. CONCLUSION: Fast absorbable sutures with antibacterial coating (Tricosan) do not increase the hernia rate after midline abdominal incision compared with slowly absorbable sutures, when wound infection rates are decreased by coating the fast absorbable suture with Triclosan. The development of incisional hernia is significantly increasing in patients with a BMI >30 kg/m(2).

Tissue reactions of suture materials (polyglactine 910, chromed catgut and polydioxanone) on rat bladder wall and their role in bladder stone formation.

Suture materials are widely used in urological surgery especially in regions that are in contact with urine. In this study, we aimed to compare polyglactine 910, chromed catgut and polydioxanone sutures according to stone formation and inflammation, congestion and foreign body reaction that occur on bladder mucosa. Cystotomy procedure was performed, in three groups of Wistar female rats, with 4/0 polyglactine 910, 4/0 chromed catgut and 4/0 polydioxanone sutures. All groups were divided into two sub-groups with 4 and 8-week follow up periods. Rats were treated with 20 mg kg(-1) day(-1) Ofloxacin (i.p.) daily until the seventh post-operative day. Urinary pH, leucocyte esterase and nitrite levels were determined. All rats were killed at the end of the follow-up period and stone formation on sutures and degrees of tissue reactions (inflammation, congestion and foreign body reaction) on bladder mucosa were compared. Tissue reactions were evaluated by the same pathologist (S. K.). Chi-square and Student's t test were used in statistical analysis (p<0.05). There was no significant difference between the mean weights of the groups. Leucocyte esterase and nitrite were negative in urine analyses. There was no significant difference between urinary pH levels of the groups with 4 and 8 weeks follow-up (p>0.05). Although the difference between the degrees of congestion in groups was not statistically significant (p>0.05), there were statistically significant differences between the degrees of inflammation and foreign body reaction in groups. Although the duration of urinary contact of suture is the main factor in stone formation on suture material, tissue reaction on mucosa and the physical structure of suture also affect this formation. We observed lower degrees of inflammation and foreign body reaction with 4/0 polydioxanone and no stone formation. We believe that polydioxanone may be useful and reliable in urological surgery due to these properties.

The properties of damaged and undamaged suture used in metal and bioabsorbable anchors: an in vitro study.

PURPOSE: The purpose of this study was to determine the mechanical properties of undamaged and damaged sutures in metal and bioabsorbable suture anchors. METHODS: Undamaged and damaged FiberWire (Arthrex, Naples, FL), Tevdek (Deknatel, Mansfield, MA), and PDS (Ethicon, Somerville, NJ) sutures were tested by a single pull to failure while being pulled parallel to the axis of either a metal or bioabsorbable suture anchor. Sutures were damaged by use of a razor blade incorporated into a custom-designed jig. The friction of the sutures through the anchor eyelets was also tested. RESULTS: For both anchor types, FiberWire was the strongest suture studied. Undamaged PDS had a significantly greater load to failure than Tevdek. Although all sutures lost significant strength when damaged, PDS lost the most, with damaged PDS becoming significantly weaker than damaged Tevdek. Damaged FiberWire was significantly stronger in metal anchors compared with bioabsorbable anchors, with failure of the bioabsorbable suture eyelet preventing testing of undamaged FiberWire. Neither undamaged nor damaged PDS or Tevdek had a significant difference in strength between metal and bioabsorbable anchors. However, in metal anchors the mechanical properties of undamaged Tevdek were inferior to those of the other undamaged sutures tested. For undamaged or damaged sutures through either anchor type, PDS suture had the highest coefficient of friction, significantly higher than FiberWire and Tevdek. All sutures, undamaged or damaged, had significantly less friction in bioabsorbable anchors compared with metal anchors. CONCLUSIONS: The FiberWire-anchor construct is significantly weaker when bioabsorbable anchors are used instead of metal anchors. For Tevdek and PDS sutures, the anchor type does not affect the strength of the construct, as the suture is the limiting factor. When used with suture anchors, PDS has the most friction of the sutures tested, potentially leading to suture damage, which disproportionately weakens PDS compared with the other sutures tested. For both undamaged and damaged sutures, bioabsorbable anchors lead to less friction than do metal anchors, which may lessen suture damage in vivo. CLINICAL RELEVANCE: The mechanical properties of damaged suture are important to all surgeons who use suture arthroscopically.

Polylactide (LTS) causes less inflammation response than polydioxanone (PDS): a meniscus repair model in sheep.

BACKGROUND: Incidence of meniscus injury has increased in today's active society. Arthroscopical refixation yields better results than partial meniscectomy. The best healing rates are achieved by sutures. As non-degradable sutures are permanent foreign bodies, slow absorbable materials are needed. A slow degradable suture with high concentration of polylactide acid, the so-called "long-term suture" (LTS, Panacryl), has been suggested to produce a higher inflammatory response than conventional polymer sutures [Vicryl, Dexon or polydioxanone (PDS)]. The aim of the study was to assess LTS for meniscus repair after a traumatic lesion and to evaluate immunological response, biodegradation and healing. METHODS: In 24 randomised sheep, a radial tear of the medial meniscus was sutured by either PDS or LTS. Twelve sham-operated animals served as control. Half of the sheep were killed after 6 months, the other half after 12 months. The medial and lateral meniscus, synovial membrane, articular cartilage and ascendant lymph nodes up to the kidney were examined. Joint effusion was evaluated by MRI. RESULTS: The synovial membrane was significantly thinner in the LTS group (6 months 85 +/- 10 microm, 1 year 100 +/- 28 microm) than in the PDS group (6 months 165 +/- 10 microm, 1 year 175 +/- 23 microm, P < 0.001) and the controls (6 months 150 +/- 17 microm, 12 months 192 +/- 21 microm, P < 0.001). The joint effusion was higher in the PDS than in the LTS group after 6 months, and tended to be higher in controls. In controls, effusion tended to be higher than in the LTS group. In all medial departments, osteoarthritis evolved much more intensely than in the lateral knee departments (P < 0.01). Bilateral lymph nodes from the groin up to the kidneys were larger (crosscut area) after 6 months in the controls (2.28 +/- 0.7 mm(2)) and PDS treated animals (2.3 +/- 0.7 mm(2)) than in the LTS group (1.3 +/- 0.3 mm(2), P < 0.001). After 1 year, node size differed significantly between controls and animals from the LTS group (1.98 +/- 0.4 mm(2) vs. 1.5 +/- 0.2 mm(2), P < 0.05), and between animals from the PDS and the LTS group (2.5 +/- 0.1 mm(2) vs. 1.5 +/- 0.2 mm(2), P < 0.001). CONCLUSION: The polylactide thread LTS causes less immunological reaction and synovitis than a polydioxanone suture (PDS). CLINICAL RELEVANCE: LTS may serve as an alternative to PDS for repair of slow healing structures such as tendons and menisci.

[Results of treatment of orbital fractures with polydioxanone sheet]. / Ocena wyników leczenia zlaman oczodolów z uzyciem folii polidioksanowej.

UNLABELLED: Orbital fractures are one of the most frequent consequences following midfacial trauma. If not treated they can lead to serious optical complications as: double vision (diplopia), restriction of ocular motility, eyeball sinking (enophthalmos). Autogenic bone grafts although still wide and effectively used for reconstruction of the fractured orbital walls present some disadvantages. This is morbidity of the donor site, unforeseen resorption, time-consuming procedure and longer postoperative care. Because of that introduction of new materials for orbital reconstruction seems to be desirable. The aim of the work was to evaluate usefulness of the polydioxanone sheets (PDS) as a reconstructive material for orbital floor fractures. MATERIAL AND METHODS: From 1. 09. 2004 to 1. 02. 2006 111 patients with orbital fractures were treated in the Department of Maxillofacial Surgery Klinikum Minden. Age of the patients was between 15- 89 years (mean 43 y.); m:w ratio 78:33. There were 54 isolated orbital floor fractures (in 3 cases with additional medial wall fracture) and 57 zygomatico-orbito-maxillary fractures. The diagnosis was based on the clinical picture and coronal CT scans. The patients were operated through a transconjunctival (72%) or an infraorbital-Mustarde (28%) access and the orbital floor (medial orbital wall) was reconstructed with PDS sheet. Control examination was performed immediately, 1 moth and 6 months after the operative treatment. RESULTS: There were 47% true "blow-out", 34% "trap-door" and 19% "en-clapet" fractures. The most important preoperative symptom was double vision (23%), restriction of ocular motility (18%), enophthalmos (3,6%), impairment of function of the infraorbital nerve (41%). Size of the defect was 3+/-1,13 cm(2) in "blow out" fracture, 1,8 +/-0,9 cm(2) in "trap-door" and 2+/-0,5 cm(2) in ,"en-clapet" ones. The primary reconstruction was successful in 97,3% of the cases. Any inflammation or reaction against implant was noted. Persistent double vision was present in 2,7%, restriction of ocular motility in 1,8% and enophthalmos in 0,9% after the primary procedure. These patients were submitted to reoperation. In 1 case badly positioned PDS sheet causing diplopia was removed. In another one, eyeball movement restriction was due to adhesions between the sheet and periorbital tissue. Visual status of this patient has improved after adhesiolysis. In 1 patient with a large bony destruction reconstruction only with PDS sheet was an inadequate treatment. In 7,2% of patients disturbances in the field of innervation of the infraorbital nerve were present 6 months after the surgery. CONCLUSIONS: Alloplastic, resorbable PDS sheets in most cases were a valuable material for the reconstruction of the orbital floor (medial orbital wall). Mechanical properties of PDS seem to be not sufficient for the reconstruction of extremely large bony defects. In these cases use of autogenic bone grafts or a titanium mesh should be rather considered.

Biodegradable polydioxanone and poly(l/d)lactide implants: an experimental study on peri-implant tissue response.

Several implants for orbital wall fracture treatment are available at the present, but they have drawbacks: resorption, risk for migration and foreign body reaction. Alloplastic resorbable implants would be advantageous: no removal operation and no donor side morbidity. The purpose of this study was to evaluate the foreign body reaction, capsule formation and mechanical properties of two bioresorbable implants. PDS and SR-P(L/DL)LA mesh sheet (70/30) with solid frame (96/4) implants (SR-P(L/DL)LA 70,96) were placed into subcutaneous tissue of 24 rats. Immunohistochemistry was used to evaluate reactivity for Tn-C, alpha-actin, type I and III collagens and two mononuclear cells: T-cells and monocyte/ macrophage. GPC, DSC and SEM were performed. Student's t-test or nonparametric Kruskall-Wallis test were used for statistical analysis. Histology of peri-implant capsule exhibited an inner cell-rich zone and an outer connective tissue zone around both materials. Tn-C reactivity was high in the inner and alpha-actin in the outer zone. At the end of the study, the difference of type I collagen versus type III collagen reactivity in inner zone was statistically significant (P<0.0001) as was the difference of type I collagen versus type III collagen reactivity in outer zone (P<0.0001). Immunohistochemistry did not reveal any statistical differences of T-cell and monocyte/macrophage reactivity around PDS versus SR-P(L/DL)LA 70,96 implants, nor any differences as a function of time. PDS were deformed totally after 2 months. SR-P(L/DL)LA 70,96 implants were only slightly deformed during the follow up of 7 months. PDS degraded rapidly in SEM observation. Particles were detaching from surface. SEM observation revealed that polylactide implant was degrading from the surface and the inner porous core became visible. The degradation came visible at 7 months. There were cracks in perpendicular direction towards to the long axis of the filaments. M(w) of PDS decreased fast compared to the polylactide implant. Foreign body reaction was minimal to both materials but continued throughout the whole observation period. Mechanically PDS was poor, it looses its shape totally within 2 months. It cannot be recommended for orbital wall reconstruction. New mesh sheet-frame structure (SR-P(L/DL)LA 70,96) approved to be mechanically adequate for orbital wall reconstruction. It seems not to possess intrinsic memory and retains its shape. The resorption time is significantly longer compared to PDS and is comparable to other studied P(L/DL)LA copolymers. Thus, the new polylactide copolymer implant may support the orbital contents long enough to give way to bone growth over the wall defect.

The relationship between five kinds of laparoscopic knots and five types of suture materials and histological findings in tissues: an experimental study on rabbits.

The aim of the current study was to examine the slipping and the tightening of laparoscopic knots with various kinds of sutures, as well as the histologic alterations in tissues. Fifty rabbits and five kinds of sutures were used-silk, polyglactine-910 (Vicryl), Polydioxanone (PDS), Polyglycol (Dexon), and cat-gut chromic-and five laparoscopic knots were used-Tayside, Roeder, Melzer, Cross, and Blood. The knots were performed extracorporeally and were used to ligate a part of the omentum. Sliding and tightening of the knots were evaluated. The omentum, the suture, and the knots were checked 10 days and 1 month after operation. Histologic examination was performed 1 month after surgery. Polyglactine-910 (Vicryl) and silk were the most qualitative sutures used in Tayside, Roeder, and Blood knots and the least harmful for the tissues. Catgut chromic and Polydioxanone (PDS) were the most defective sutures. The most efficient laparoscopic slipknots are Tayside, Roeder, and Blood, especially when constructed with silk and polyglactine-910 (Vicryl).

Orbital floor reconstruction with an alloplastic resorbable polydioxanone sheet.

The orbital floor is frequently reconstructed after blow-out fractures or midface fractures to avoid a relapse of the repositioned orbital tissue and to prevent enophthalmos. A total of 31 patients underwent reconstruction of internal orbital wall fractures with a resorbable 0.25 mm or 0.5 mm-thick polydioxanone implant (PDS). Skeletal and functional outcome was evaluated retrospectively with regard to fracture size. Fracture size was graded as small, moderate or large by CT scans and operating records. Two of the 25 patients with small or moderate defects showed an enophthalmos of 2-3 mm. Five of the six patients with large defects or two orbital wall fractures had enophthalmos. The scar that formed after implant resorption was to weak to provide adequate support of the globe or to compensate the enlarged orbital volume. Endoscopic follow-up examination of 12 patients showed yielding of the scar in the orbital floor already in moderate defects. Eight patients had diplopia in extreme gaze and two had significant diplopia. Blow-out and midfacial fractures with small to moderate defects in the orbital floor (up to a size of 2.5 cm2) can be reconstructed by polydioxanone sheet to avoid enophthalmos. Polydioxanone implants should only be used in cases without massive orbital fat herniation. The scar formed after implant resorption may influence functional outcome.