Long-term evaluation of three-dimensional volumetric changes of augmented severely atrophic maxilla by anterior iliac crest bone grafting.

PURPOSE: The purpose of this study was to evaluate long-term three-dimensional graft resorption following reconstruction of the severely atrophic maxilla with anterior iliac crest bone grafting. METHODS: Twenty-two patients (13 males), who underwent autogenous bone grafting and implant placement to their severely atrophic maxillary alveolar ridges were identified and included in the study. Pre- and postoperative cone-beam computed tomography (CBCT) scans of 40 recipient grafting sites were evaluated to calculate volumetric changes over time. CBCT scans were performed preoperatively (V0) and one week (V1), three months (V2), one year (V3), and three years (V4) following the augmentation operation. RESULTS: The average graft resorption from V1 to V2, V1 to V3, and V1 to V4 was 31.42%, 33.96%, and 37.96%, respectively. Initial graft volume reduction within the first three months was statistically higher compared to other postoperative periods (P<0.013). The rate of resorption reduced slightly from the third month of the surgery (V2) (P>0.013). There was no statistical difference between resorption volume and gender, type of prosthesis, the presence of vestibuloplasty, or patient age (P>0.05). CONCLUSION: The overall success rate of the iliac bone block grafts was found to be high. The volumetric resorption rates associated with the graft were favourable for the reconstruction of the maxilla and for permitting the placement of dental implants three months after augmentation. The highest graft resorption was found at the third postoperative month. Placement and loading of the implants reduced the resorption rate slightly over time.

Histological Evaluation of the Effects of Growth Factors in a Fibrin Network on Bone Regeneration.

OBJECTIVE: The aim of this study was to evaluate the effect of mineralized plasmatic matrix (MPM), comprising a combination of synthetic graft and platelet concentrates, on bone regeneration. METHODS: Critical size defects of 6-mm diameter were created on the tibias of 6 male sheep, with the animals subsequently assigned into 2 groups. Of the 5 bone defects generated per animal, 4 were randomly filled with MPM, beta-tricalcium phosphate graft (ß-TCP), platelet-rich fibrin (PRF) + ß-TCP, and autogenous graft. One defect was left empty as a control group. Animals were killed at 3 weeks (early healing group) and 6 weeks (late healing group). The specimens underwent histologic and histomorphometric analysis to evaluate new bone formation. RESULTS: In both healing periods, new bone formation from autogenous bone was observed significantly more often than from biomaterials or the empty defect. The degree of new bone formation for MPM was significantly higher than that of the control group at all healing periods. In addition, it was significantly higher in both healing periods than that of ß-TCP albeit only in the late healing period than that of the PRF + ß-TCP combination. In all biomaterial groups, residual graft ratios decreased from early to late healing periods. CONCLUSION: The results indicated that MPM, representing growth factors in a fibrin network, increases new bone formation in surgically created defects in sheep tibia as confirmed by histologic assessment.

Clinical and 3-Dimensional Radiographic Evaluation of Autogenous Iliac Block Bone Grafting and Guided Bone Regeneration in Patients With Atrophic Maxilla.

PURPOSE: To evaluate the rate of graft resorption in autogenous iliac bone grafting (IBG) and guided bone regeneration (GBR) in patients with atrophic maxillae. MATERIALS AND METHODS: We performed a retrospective study involving patients requiring implant placement who underwent IBG or GBR. Volumetric changes of the graft sites were evaluated by imaging studies. The primary predictor and outcome variables were augmentation technique and rate of volumetric resorption, respectively. Secondary outcome variables included bone gain, success of grafting, insertion torque of implants, and requirement for vestibuloplasty. RESULTS: The sample comprised 39 patients (21 with GBR and 18 with IBG). One patient in the IBG group had temporary sensory disturbance at the donor site, and one patient in the GBR group had late exposure of the nonresorbable membrane. The average values of percent volume reduction in the GBR and IBG groups were 12.26% ± 2.35% and 35.94% ± 7.94%, respectively, after healing and 15.87% ± 1.99% and 41.62% ± 6.97%, respectively, at last follow-up. The IBG group exhibited a significantly higher reduction in bone volume than the GBR group at both time points (P = .001). The mean values of horizontal and vertical bone gain after healing in the IBG group were significantly higher than those in the GBR group (P = .006 and P = .001, respectively). The mean implant torque during implant placement in the GBR group was significantly higher than that in the IBG group (P = .024). There was no significant difference in the requirement for vestibuloplasty between the two groups (P > .05). CONCLUSIONS: Although both hard tissue augmentation approaches provide an adequate volume of bone graft for implant insertion, IBG results in greater graft resorption at maxillary augmented sites than GBR. Clinicians should consider the differences in the extent of graft resorption between the two methods while choosing the treatment approach.

Comparison of Bone Resorption Rates after Intraoral Block Bone and Guided Bone Regeneration Augmentation for the Reconstruction of Horizontally Deficient Maxillary Alveolar Ridges.

Purpose. Bone atrophy after tooth loss may leave insufficient bone for implant placement. We compared volumetric changes after autogenous ramus block bone grafting (RBG) or guided bone regeneration (GBR) in horizontally deficient maxilla before implant placement. Materials and Methods. In this retrospective study, volumetric changes at RBG or GBR graft sites were evaluated using cone-beam computed tomography. The primary outcome variable was the volumetric resorption rate. Secondary outcomes were bone gain, graft success, and implant insertion torque. Results. Twenty-four patients (28 grafted sites) were included (GBR, 15; RBG, 13). One patient (RBG) suffered mucosal dehiscence at the recipient site 6 weeks after surgery, which healed spontaneously. Mean volume reduction in the GBR and RBG groups was 12.48 ± 2.67% and 7.20 ± 1.40%, respectively. GBR resulted in significantly more bone resorption than RBG (P < 0.001). Mean horizontal bone gain and width after healing were significantly greater in the GBR than in the RBG group (P = 0.002 and 0.005, resp.). Implant torque was similar between groups (P > 0.05). Conclusions. Both RBG and GBR hard-tissue augmentation techniques provide adequate bone graft volume and stability for implant insertion. However, GBR causes greater resorption at maxillary augmented sites than RBG, which clinicians should consider during treatment planning.

Does Combined Spinal Epidural Anesthesia Decrease the Morbidity of Iliac Block Bone Grafting for Deficient Alveolar Ridges Compared With General Anesthesia?

PURPOSE: To evaluate the morbidity of iliac block bone grafting performed under general anesthesia (GA) or combined spinal epidural anesthesia (CSEA). MATERIALS AND METHODS: We implemented a retrospective study including patients who underwent anterior iliac block bone grafting for deficient maxillary alveolar ridges. The anesthetic technique (GA or CSEA) was the primary predictor variable. The outcome variables were pain, gait disturbance, neurosensory disturbance (0 to 5 weeks), vomiting tendency (0 to 7 days), and postoperative hospitalization period (0 to 2 days). RESULTS: The sample comprised 22 patients, with 10 in the GA group and 12 in the CSEA group. No surgical complications except sensory disturbance in 2 patients were observed during the study period. Pain during initial healing (P < .001), the gait disturbance rate at 3 weeks after surgery (P = .003), and the vomiting tendency on the day of surgery (P < .001) were significantly higher in the GA group than in the CSEA group; all variables showed significant improvement with time in both groups. The postoperative hospitalization period was also significantly longer for the GA group than for the CSEA group (P < .001). No significant difference was observed between groups with regard to neurosensory disturbance. CONCLUSIONS: Iliac block bone grafting for deficient maxillary ridges can be successful under both GA and CSEA, although CSEA results in less pain and vomiting and early recovery, thus increasing patient comfort.

Histologic and Histomorphometric Comparison of Bone Regeneration Between Bone Morphogenetic Protein-2 and Platelet-Derived Growth Factor-BB in Experimental Groups.

Efficacy of recombinant human bone morphogenetic protein-2 (rhBMP-2) and recombinant human platelet-derived growth factor-BB (rhPDGF-BB) delivered via absorbable collagen sponge (ACS) on bone formation was evaluated in guinea pig tibias. Three-millimeter-circular bone tibia defects were created in 24 guinea pigs assigned randomly to 4 groups according to the following defect filling materials: ACS only, rhBMP-2+ACS, rhPDGF-BB+ACS, or empty. New bone formation was evaluated histologically and histomorphometrically at 15 (early healing) and 45 days (late healing). Mean new bone per total defect area ratio was 0.73, 0.57, 0.43, and 0.42 in rhBMP-2+ACS, rhPDGF-BB+ACS, ACS only, and empty groups at early healing, respectively. During early healing, significantly more new bone formation was observed in rhBMP-2+ACS and rhPDGF-BB+ACS groups than in the control groups. New bone formation was significantly higher with rhBMP-2+ACS than with rhPDGF-BB+ACS. Mean new bone per total defect area ratio was 0.81, 0.86, 0.74, and 0.75 in the rhBMP-2+ACS, rhPDGF-BB+ACS, ACS only, and empty groups at late healing, respectively. During late healing, new bone formation was significantly higher in the rhPDGF-BB+ACS group relative to both control groups, but the results did not differ significantly from those in the rhBMP-2+ACS group. New bone formation in the rhBMP-2+ACS group did not change significantly between the healing periods. In the rhPDGF-BB+ACS group, however, new bone formation was significantly higher in the late healing period. Both growth factors accelerated new bone formation in the early healing period. Although rhBMP-2 was more effective in the early healing period, the effects of rhPDGF-BB were longer lasting.

Evaluation of Volumetric Changes of Augmented Maxillary Sinus With Different Bone Grafting Biomaterials.

Extensive alveolar bone resorption because of pneumatized maxillary sinus is a common problem that limits dental implant placement. Maxillary sinus floor augmentation (MSFA) is an accepted treatment protocol that provides sufficient bone volume. The aim of this study was to evaluate the percentage of graft volume reduction following MSFA using cone beam computed tomography. In this retrospective study, cone beam computed tomography scans of MSFA were measured to evaluate the volume of the grafted sinus with deproteinized bovine bone (DBB), mineralized allograft (MA), or a mixture of MA and demineralized allograft as a composite. The volumetric changes in sinus augmentation between 2 weeks (T-I) and 6 months (T-II) after operation were analyzed. Thirty-nine patients were included in this study. The average percent volume reduction was 8.14 ±â€Š3.76%, 19.38 ±â€Š9.22%, and 24.66 ±â€Š4.68% for DBB, MA, and composite graft, respectively. A significant graft volume reduction was found between T-I and T-II for all groups (P < 0.01). The DBB group showed the least volume reduction (P < 0.01). Biomaterials can influence the bone graft volume change before implant placement. Deproteinized bovine bone may offer greater volume stability during healing than mineralized and composite allografts.

Clinical evaluation of the stability of implants placed at different supracrestal levels.

PURPOSE: The aim of this study was to evaluate the stability during healing and before loading of implants placed at two different supracrestal levels according to their collar texture. MATERIALS AND METHODS: This retrospective study included patients who received posterior implants with the same macro design. Implants with a machined collar were placed 0.3 mm above the crestal bone (M group), while those with a laser-microtextured collar were placed 1 mm above the crestal bone (L group). All implants healed in a single stage with healing abutments. Implant stability quotient (ISQ) values were determined using resonance frequency analysis immediately after implant placement during surgery and after 1, 4, 8, and 12 weeks after surgery. Other evaluated factors for stability included the implant diameter and length and the site of placement (maxilla or mandible). RESULTS: In total, 103 implants (47 L, 56 M) were evaluated. The median ISQ values at baseline and 1 week after placement were significantly higher for the M group than for the L group (p=0.006 and p=0.031, respectively). There were no differences at the subsequent observation points. The ISQ value was higher for wide-diameter than regular diameter (p=0.001) and mandibular implants than maxillary implants (p=0.001 at 0-8. weeks; p=0.012 at 12 weeks) at all observation points. When diameter data were neglected, the implant length did not influence the ISQ value at all observation points. CONCLUSION: Our results suggest that submerging implant more inside bone may only influence primary stability. Moreover, the implant diameter and site of placement influence primary and secondary stability before loading, whereas the implant length does not when its diameter is not accounted for.

Clinical evaluation of marginal bone loss and stability in two types of submerged dental implants.

PURPOSE: The aim of this prospective clinical trial was to compare the three-dimensional marginal bone level, implant stability, and peri-implant health of two types of submerged dental implants that were restored with matching or platform-switched abutments. MATERIALS AND METHODS: Twenty-five subjects were recruited (test group: 43 implants with internal conical connection and back-tapered collar carrying a platform-switched abutment; control group: 50 implants carrying a matched-platform abutment). Implant uncovering and conventional loading were performed after 3 months of healing, and the total observation time was 15 months. Marginal bone levels, resonance frequency analysis, insertion torque, and peri-implant health indices were recorded and analyzed statistically. RESULTS: The cumulative implant survival rate was 100%. At the second-stage surgery, bone levels were similar between groups. One year after loading, mean crestal bone loss was 0.35 ± 0.13 mm for test implants and 0.83 ± 0.16 mm for control implants, a significant difference. Primary stability was significantly higher in the test group than in the control group, but this difference disappeared after 3 months of healing prior to loading. Between-group differences for peri-implant health indices were negligible. CONCLUSIONS: Both implant systems had the same survival rates. Implants with a built-in platform switch and conical connection with back-tapered collar design achieved higher primary stability at insertion and less bone resorption after 15 months.

Surgery-related complications in cardiac transplantation patients.

OBJECTIVE: The surgical techniques was first described by Lower and Shumway for cardiac transplantation have not changed for many years; they are still being commonly used worldwide despite recently presented alternatives. We sought to evaluate the surgical complications among our cardiac transplantation patients in whom we performed the standard technique. PATIENTS AND METHODS: The standard biatrial anastomosis technique was used in 13 patients who have a mean follow-up of 18.6 (1 to 38) months. During the follow-up, echocardiographic assessment was performed to evaluate left and right atrial diameters, tricuspid and mitral valve regurgitation, interatrial septum, and suture lines. Elecotrocardiograms were evaluated for arryhthmia and pacemaker requirements in the midterm. RESULTS: The mean left and right atrial diameters were measured as 40.5 (32 to 57) x 66.6 (48 to 78) and 37.9 (32 to 43) x 56.3 (48 to 69) mm, respectively. The jet area was calculated at less than 5 cm(2) for mitral and tricuspid valve regurgitation, which can be defined as "mild" regurgitation. There was no increase in the degree of regurgitation of both atrioventricular valves during the follow-up period. In one patient, a thrombus was detected in the suture line; there was a nonsignificant left to right shunt in another patient. A temporary pacemaker was indicated in two patients. Atrial fibrillation was detected in three patients, who responded to medical therapy. During the follow-up atrial fibrillation developed in one patient. CONCLUSION: The cardiac transplantation operation using the standard technique may result in atrial dysfuntion due to deformation of atrial integrity and geometry. However, when we evaluated our results, we concluded that the standard surgical technique was a safe, simple, effective, and feasible method.

The midterm results of cardiac transplantation patients.

OBJECTIVE: Cardiac transplantation is an important treatment option that increases the survival and decreases the limitations in effort capacity among patients with end-stage heart disease. In this study we have presented the midterm results of 13 patients who underwent cardiac transplantation between 2003 and 2007. PATIENTS AND METHODS: There were 10 male and three female patients of mean age of 32 +/- 13.27 years (12 to 54). In one patient, we performed combined cardiac and renal transplantation. Ischemic cardiac disease was present in six patients and cardiomyopathy in seven patients. The mean age of the donors was 23.3 +/- 11.8 years (12 to 46). Corticosteroids, cyclosporine, and mycophenolate mofetil were used for immunosuppression. Sirolimus was employed in five cases due to impaired renal function. Patients were followed by echocardiography, endomyocardial biopsy, and dobutamine stress echocardiography. RESULTS: The mean follow-up was 18.6 +/- 13.4 (1 to 38) months. In four patients, there was grade IIIA (II-R) rejection. In five patients, tacrolimus or cyclosporine was replaced with sirolimus due to elevated creatinine levels. Dobutamine stress echocardiography was positive in one patient, who displayed a severe left main coronary artery lesion. There was no operative mortality. There was only one hospital mortality (7.6%). Two patients died in the midterm. The overall mortality on follow-up was 3 (23.1%). The survival rates in the first, second, and third years were 92%, 88%, and 75%, respectively. Ejection fraction were more than 50%; all of posttransplant survivors showed good effort capacity. CONCLUSION: Cardiac transplantation is a definitive, safe, and effective treatment for patients with end-stage heart failure.

Successful cardiac transplantation from donor with carbon monoxide intoxication: a case report.

BACKGROUND: The use of hearts for cardiac transplantation from donors with brain death due to exposure to high concentrations of carbon monoxide is still under discussion. In this short report we have presented a patient who underwent a successful cardiac transplantation from a brain-dead donor who had cardiopulmonary resuscitation after carbon monoxide intoxication. METHOD: A standard biatrial anastomosis technique was used in our patient. The transplantation was uneventful with donor ischemic time of 180 minutes. The patient was treated with mechanical ventilation for 72 hours. The donor liver biopsy during harvesting did not reveal irreversible changes. Although the donor had a history of cardiopulmonary resuscitation, the left ventricular ejection fraction was 55% and the echocardiographic evaluation revealed normal cardiac contractions with acceptable hemodynamic parameters. Positive inotropic support was needed in the early postoperative period. We did not observe any changes related to intoxication in the endomyocardial biopsy. CONCLUSIONS: We concluded that successful heart transplantation can be performed using hearts from patients succumbing to carbon monoxide poisoning in the presence of adequate cardiac functional parameters. This group will increase the number of cardiac transplantations and decrease the incidence of deaths among patients on transplantation lists.

Xenograft transplantation in congenital cardiac surgery at Baskent University: midterm results.

OBJECTIVE: Xenograft valved conduits have been used in several cardiac pathologies. In this study we have presented our midterm results of pediatric patients pathologies who were operated with xenograft conduits. PATIENTS AND METHODS: Between January 1999 and January 2005, 134 patients underwent open heart surgery with xenograft conduits. The conduits were used to establish the continuity of the right ventricle to the pulmonary artery or aorta, the left ventricle to the pulmonary artery, or aorta due to various types of complex cardiac anomalies. Patients were evaluated by transthoracic echocardiography (ECHO) at 6-month follow-ups. Cardiac catheterization was performed when ECHO demonstrated significant conduit failure. RESULTS: Hospital mortality was observed in 28 patients (20.1%), and 13 patients died upon follow-up (9.7%). Mean follow-up was 24.6 +/- 4 months (range, 13 to 85 months). Among 93 survivors 20 patients (21.5%) were reoperated due to conduit failure. The main reasons for conduit failure were stenosis (n=13), valvular regurgitation (n=2), or both conditions in 5 cases. Mean pulmonary gradient before conduit re-replacement was 47.7 +/- 30.1 mmHg. The 1-, 3-, and 6-year actuarial survival rates were 95 +/- 2%, 91 +/- 3%, and 86 +/- 5%. The 1-, 3-, and 6-year actuarial freedom rates from reoperation were 95 +/- 1%, 90 +/- 3%, and 86 +/- 4%. An increased gradient between the pulmonary artery and the right ventricle and prolonged cardiopulmonary bypass times were observed to be significant risk factors for reoperation. There was no mortality among reoperated patients. CONCLUSION: Xenograft conduits should be closely followed for calcification and stenosis. Conduit stenosis is the major risk factor for reoperation. In these patients, reoperation for conduit replacement can be performed safely before deterioration of cardiac performance.

Our experience in cardiac transplantation in Baskent University.

Recently cardiac transplantation has an important place in treatment of end-stage cardiac failure. In Turkey between 2003 and 2005 at 10 centers 64 cardiac transplantations were performed including five at our facility. Herein we have presented our results. All patients were men of mean age 34.2 +/- 10.7 (17 to 44) years. Upon preoperative echocardiography their mean ejection fraction was 18% +/- 3.27% (17% to 23%). Pulmonary vascular resistance was 4.47 wood unit in one patient and in one case, there was Rh incompatibility between donor and recipient. We used HTK solution for protection of donor hearts. Mean ischemia time was 251.2 +/- 62.7 minutes (155 to 314). Mean aortic clamping time was 84 +/- 4.7 minutes (80 to 90). In all patients we performed a biatrial anastomosis technique. Hemofiltration was used to prevent hemodilution during operation. In the postoperative period four patients had acute renal dysfunction; one, a minor cerebrovascular accident; two, reoperated because of bleeding; one, cholestasis; one, temporary atrio-ventricular block; and one, mediastinitis. Mean follow-up time was 15.6 +/- 19.7 months (2 to 50). Neither early nor late mortality has occurred. All patients are in New York Heart Association class I. In all cases we used triple immunosuppressive therapy. In the follow-up period the mean number of cardiac biopsies per patient was 4.2 +/- 3.03 (2 to 8). Two cases had cardiac catheterization. As a complication of cardiac biopsy, pericardial tamponade developed in one patient; in another one we observed a right ventricular aneursym after cardiac biopsy. Cardiac transplantation was performed with low mortality and morbidity rates in end-stage cardiac failure patients with longer life expectancy and higher life quality. Unfortunately in our country, because of difficulties to find donor hearts, cardiac transplantations were small in number. For better results, we need a larger series.

Extrapleural hematoma: when is surgery indicated?

Extrapleural haematoma (EH) is a rare clinical condition of which four cases are presented. Different etiologies were encountered. Identical findings were found on the chest X-ray. Two cases were secondary to spontaneous rib fracture and the other two were iatrogenic. Surgical exploration was necessary in one patient following pleural biopsy. Medical treatment and clinical observation were the treatment of choice in the remaining three stable patients.

Low-dose histidine-tryptophan-ketoglutarate solution for myocardial protection.

The effect of histidine-tryptophan-ketoglutarate (HTK) solution for myocardial protection has been shown in experimental and clinical studies using long ischemic times and high dosages. In our study we compared myocardial protection in isolated coronary bypass with a short period of ischemia using low dosage HTK and cold crystalloid cardioplegia. Each group contained 21 coronary artery disease patients. Cardioplegic solutions were administered antegrade in 10 to 15 mL/kg in one shot. This dosage of HTK was lower than that mentioned in the literature. We measured malondialdehyde, lactate, creatine kinase, creatine kinase-MB, and troponin-I levels. Aortic clamping time in the HTK group 33.9 +/- 8.2 minutes, versus 36.2 +/- 11.3 minutes in the crystalloid cardioplegia group (P > .05). Levels of creatine kinase and malondialdehyde were lower in HTK group at 24 hours and 2 minutes, respectively. Lactate levels were lower in the crystalloid cardioplegia group at 2 minutes in the coronary sinus serum sample, but there were no statistically differences among ischemic serum markers in both groups. Only intervals between aortic clamping and cardiac arrest were statistically meaningful (HTK 63.3 +/- 14.7 seconds versus crystalloid cardioplegia 53.6 +/- 15.6 seconds, P = .044). Our study shows that use of low-dose HTK for short clamping time operations is as successful for myocardial protection as crystalloid cardioplegia. Longer times for fibrillation can be explained with the low levels of potassium in HTK solution, but this length did not cause a biochemical or clinical difference.

Effect of ultrasonic energy in washing of medical surgery gowns.

Today, the use of medical textiles is very important for health and hygienic purposes. Although some of medical textile materials are disposable, surgery gowns are usually laundered and re-used. After the laundering it is desirable to have these gowns keeping some of their properties such as anti-microbial and tenacity properties. For this in mind, different surgery gowns were washed and compared. In this work, a special blend of polyester carbon anti-microbial and other surgery gowns were stained with blood and later washed with both conventional method and with ultrasonic energy. The results were also analysed spectrophotometrically and the tenacity of the fabrics were determined.