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The effect of donor age on graft survival in pediatric cadaver renal transplant recipients--a report of the North American Pediatric Renal Transplant Cooperative Study.

Data from the North American Pediatric Renal Transplant Cooperative Study were analyzed to determine the effect of donor age on graft survival for pediatric recipients of cadaver donor renal transplants. Between January 1, 1987, and November 16, 1990, 787 cadaver donor renal transplants in children less than 18 years of age were registered in the study. The ages of the donors were less than or equal to 5 years in 203 transplants, between 6 and 9 years in 87, between 10 and 39 in 389, and greater than or equal to 40 years in 108. The risk of graft loss was related to donor age by a proportional hazards analysis. The ideal donor age was 20-25 years. The risk of graft loss was increased by both young and old donor age. The risk of graft loss from a neonate donor was 2.7-fold that of the ideal donor, and the risk from a 50-year-old donor was 1.8-fold that of the ideal donor. The relationship between donor age and graft survival was not affected by the age of the recipient. Cold storage time had an added impact on graft survival: grafts with cold storage time greater than 24 hr were 1.5 times more likely to fail than grafts with shorter cold storage time for all donor ages. Analysis of the causes of graft failure revealed that 9.9% of grafts from donors less than or equal to 5 years of age were lost due to vascular thrombosis, primary nonfunction, and other technical causes, compared with 4.6% in 6-9, 4.4% in 10-39, and 2.8% in greater than or equal to 40-year-old donors. We conclude that kidneys from both young and old donors are at increased risk for graft loss, and this increased risk is seen in all recipient age groups. Many of the losses from the young donors--but not older donors--may be due to technical causes. Knowledge of these risks can be used to develop strategies for optimal utilization of kidneys from young and old donors.

Adolescent↗

A proposal for improved cadaver kidney allocation.

The allocation of cadaver kidneys for transplantation should have two objectives: a fair distribution of kidneys among the waiting recipients and a high success rate. Currently, organ exchange organizations are following mainly a policy of success oriented allocation in that the kidneys are distributed according to the best achievable HLA match. A consequence of this policy is that patients with rare HLA phenotypes experience prolonged waiting times and that there are large kidney exchange imbalances among transplant centers. Based on theoretical considerations, we described previously the selection routine COMB which was aimed at decreasing excessive waiting times. In this study we present an extension of this routine called XCOMB which builds on realistic conditions according to the current Euro-transplant waiting list. This new procedure decreases the average and maximum waiting time, adjusts for rare HLA phenotypes and HLA homozygosity, provides for a reasonably balanced kidney exchange rate among centers, and guarantees an HLA match distribution and overall transplant success rate near the theoretically possible optimum. The program was tested in an extensive simulation based on actual data derived from 35,000 cadaver kidney transplants. Although more complex than procedures currently in use, the program's efficient software allows the selection of a patient within one second from a waiting list of 10,000 potential recipients, using readily available computer hardware.

Algorithms↗

Delayed graft function, acute rejection, and outcome after cadaver renal transplantation. The multivariate analysis.

The impact of delayed graft function on outcome after cadaver renal transplantation has been controversial, but most authors fail to control their analyses for the presence or absence of rejection. We studied 457 adult recipients of primary cadaver allografts at a single institution during the cyclosporine era. All patients received sequential immunosuppression. The incidence of delayed graft function (defined as dialysis being required during the first week after transplant) was 23%. There was a significant association between delayed graft function and cold ischemia time > 24 hr (P = 0.0001) and between delayed graft function and the occurrence of at least one biopsy-proven rejection episode (P = 0.004). Actuarial graft survival was not significantly different when comparing delayed graft function versus no delayed graft function for patients without rejection (P = 0.02). However, it was significantly worse for patients with both delayed graft function and rejection versus those with delayed graft function but no rejection (P = 0.005), as well as for grafts preserved > 24 hr versus < or = 24 hr (P = 0.007). By multivariate analysis, delayed graft function per se was not a significant risk factor for decreased graft survival for patients without rejection (P = 0.42). In contrast, rejection significantly decreased graft survival for grafts with immediate function (relative risk = 2.3, P = 0.0002), particularly in combination with delayed graft function (relative risk = 4.2, P < 0.0001). While cold ischemia time > 24 hr was also a significant risk factor (relative risk = 1.9, P = 0.02), other variables (preservation mode, 0 HLA Ag mismatch, age at transplantation, gender, diabetic status, and panel-reactive antibody at transplantation) had no impact on graft survival. Patient survival was significantly affected by the combination of delayed graft function and rejection (relative risk = 3.1, P < 0.0001), age at transplantation > 50 years (relative risk = 2.6, P < 0.0001), and diabetes (relative risk = 1.8, P = 0.006). Further studies are necessary to elucidate the mechanisms linking delayed graft function and rejection, which, in combination, lead to poor allograft outcome.

Adult↗

An assessment of the effects of cadaver donor bone marrow on kidney allograft recipient blood cell chimerism by a novel technique combining PCR and flow cytometry.

A new technique, the PCR-flow assay is described that has allowed for the serial identification and quantitation of discrete mononuclear cell subsets of donor (or recipient) bone marrow derived cells in cadaver kidney transplant recipients infused postoperatively with donor vertebral body bone marrow cells. With fixed permeabilized cells in flow cytometry the amplification power of the polymerase chain reaction (PCR), using fluorescent-labeled primers to identify single copy HLA class II DRbeta1 genes of either donor or recipient origin, is combined with multi-color fluorochrome-labeled CD epitope-specific monoclonal antibodies. The details of the methodology are described; these support the utility of the assay. Initial observations were made on the chimeric makeup of the peripheral blood as well as iliac crest bone marrow between six months and one year posttransplantation in recipients serially followed weekly and then monthly, concomitantly compared with a control group of stable kidney transplant recipients using similar therapeutic protocols, who did not receive cadaver bone marrow. Several findings are of note. In 14 recipients of two bone marrow infusions totalling a mean of 6.29+/-2.18x10(10) cells, donor CD34 positive (+) (immature) cells were fourteen times as numerous in peripheral blood six months postoperatively as in six recipients given half as many bone marrow cells in one infusion (averaging 3.02+/-0.5x10(10)). These donor CD34+ cells unexpectedly averaged 36+/-7% of the total (donor plus recipient) CD34+ subset counted. Moreover, iliac crest bone marrow aspirates contained an average of thirteen times this number of CD34+ cells than in the peripheral blood, supporting the notion of engraftment. Of additional interest, between six months and one year posttransplant although no donor cells could be detected in peripheral blood of the controls there was an identifiable presence of donor CD34+ cells in their iliac crest bone marrow, albeit 10-fold less than the marrow-infused patients. In the clinical follow-up, although there were three unrelated mortalities, there were no additional kidney losses with current serum creatinine concentrations averaging 1.3+/-0.06 mg/dl. In conclusion, the PCR-flow assay presents the possibility of identifying discrete subsets of donor or recipient cells that may have an immunoregulatory function.

Adoptive Transfer↗

Prospective evaluation of pretransplant blood transfusions in cadaver kidney recipients.

BACKGROUND: A beneficial effect of pretransplant transfusions on graft survival was demonstrated in the early 1970s. In the mid-1980s, however, retrospective studies showed that transfusions had lost their graft-protective effect in the cyclosporine era. During the last 10 years, deliberate transfusion pretreatment of transplant patients has been discontinued. METHODS: Within a collaborative project of 14 transplant centers, prospective recipients of cadaver kidney grafts were randomized to receive either three pretransplant transfusions or transplants without transfusions. RESULTS; The graft survival rate was significantly higher in the 205 transfusion recipients than in the 218 patients who did not receive transfusions (at 1 year: 90+/-2% vs. 82+/-3%, P=0.020; at 5 years: 79+/-3% vs. 70+/-4%, P=0.025). Cox regression analysis showed that this effect was independent of age, gender, underlying disease, prophylaxis with antilymphocyte antibodies, and preformed lymphocytotoxins. CONCLUSIONS; Transfusion pretreatment improves the outcome of cadaver kidney transplants even with the use of modern immunosuppressive regimens.

Blood Transfusion↗

Antilymphocyte induction therapy in cadaver renal transplantation: a retrospective, multicenter United Network for Organ Sharing Study.

Antilymphocyte induction therapy in cadaver renal transplantation is controversial. The effectiveness of antilymphocyte therapy in the current era of cyclosporine and tacrolimus use has been questioned. The United Network for Organ Sharing data set for the Center-Specific Outcomes Analysis, which has been verified by the transplant centers, was used for this study. At the time information in the database was confirmed, all transplant centers were queried on their use of an antilymphocyte preparation at the time of transplantation, and whether it was used within 24 hr of transplant surgery, the duration of the specific reagent. This allowed us to analyze 24,191 cadaver transplant procedures performed between the October 1, 1987, and the January 31, 1991. Using Cox regression analysis, as well as semiparametric logistic regression models, we demonstrated improved allograft outcomes in patients who received either Minnesota antilymphocyte globulin for 5 days or more or OKT3 for 7 days or more. The relative risk was 0.82 for Minnesota antilymphocyte globulin and 0.86 for OKT3 (for both, P<0.001). Semiparametric models were then used to compare the effectiveness of the antilymphocyte preparation in both a patient with at least a three-antigen mismatch and patients who had a zero-antigen mismatch. The improvement in graft survival was seen in both match grades. These data demonstrate the improved outcomes with the use of antilymphocyte preparations during the early posttransplant period in the modern cyclosporine era.

Antibodies, Monoclonal↗

Risk factors for renal allograft survival from pediatric cadaver donors: an analysis of united network for organ sharing data.

BACKGROUND: The shortage of cadaveric donors for kidney transplantation has prompted many centers to use cadaver kidneys from pediatric donors. Use of kidneys from pediatric donors has been shown to have a lower graft survival. METHODS: Recipients receiving cadaver kidneys from pediatric and adult donors between 1988 and 1995 were analyzed. The data were obtained from United Network of Organ Sharing database. The actuarial kidney transplant graft survival was estimated by the Kaplan-Meier method. A logistic regression analysis was used to identify various risk factors for 1-year graft failure. Odds ratios (OR) were estimated for various risk factors. RESULTS: Kidney transplant survival rates for donor age <18 years (n=12,838) at 1, 2, 3, 4, and 5 years were 81.5%, 76.3%, 71.3%, 66.4%, and 61.7%, respectively. The corresponding results for adult donors from age 18 to 50 years (n=35, 442) were 83.5%, 78.4%, 73.1%, 67.9%, and 62.4%, respectively, Log-rank test P<0.01. Pediatric donors were further divided into three groups according to donor age: group I (0-5 years), group II (6-11 years), and group III (12-17 years). The actuarial survival rates for 1, 3, and 5 years for group I (n=2198) were 73.6%, 63.3%, and 55.6%, respectively. The corresponding values for group II (n=2873) were 78.0%, 67.5%, and 57.8% and for group III (n=7767) were 85%, 75.0%, and 64.8%, respectively, P<0.01. Although the recipients of group I had lower graft survival, en bloc grafts (n=751) had much better 1-, 3-, and 5-year graft survival rates (76.3%, 67.7%, and 60.7%, respectively) compared with single grafts (n=1447; 72.2%, 61.1%, and 53.2%, P=0.02) from donors 0 to 5 years. Graft thrombosis as a cause of graft failure was seen in 10% of group I compared with 6% in group II and 5% in group III. In group I, lower OR were seen when an en bloc transplant was performed (0.688, P<0.01) and when donor body weight was>15 kg (0.547, P<0.01). However, OR were elevated in recipients of previous transplants (1.556, P<0.01), with prolonged cold ischemic time (1.097, P=0.03), for black recipients (1.288, P=0.03), and for recipients with body mass index> or =25 (1.286, P=0.02). Progressive increase in the donor age was associated with lower OR in group II (0.894, P<0.01). CONCLUSIONS: (1) Overall, poorer graft survival was seen in pediatric donor transplants, (2) transplant kidney survival with en bloc kidneys was better than a single kidney from donors 0-5 years, (3) progressive increase in donor age was associated with improved graft survival when the donors were 6-11 years, whereas progressive increase in donor weight was associated with improved graft survival when the donors were 0-5 years.

Adolescent↗

Financial incentives for cadaver organ donation: an ethical reappraisal.

A panel of ethicists, organ procurement organization executives, physicians, and surgeons was convened by the sponsorship of the American Society of Transplant Surgeons to determine whether an ethically acceptable pilot trial could be proposed to provide a financial incentive for a family to consent to the donation of organs from a deceased relative. An ethical methodology was developed that could be applied to any proposal for monetary compensation to elucidate its ethical acceptability. An inverse relationship between financial incentives for increasing the families' consent for cadaver donation that clearly would be ethically acceptable (e.g., a contribution to a charity chosen by the family or a reimbursement for funeral expenses) and those approaches that would more likely increase the rate of donation (e.g., direct payment or tax incentive) was evident. The panel was unanimously opposed to the exchange of money for cadaver donor organs because either a direct payment or tax incentive would violate the ideal standard of altruism in organ donation and unacceptably commercialize the value of human life by commodifying donated organs. However, a majority of the panel members supported reimbursement for funeral expenses or a charitable contribution as an ethically permissible approach. The panel concluded that the concept of the organ as a gift could be sustained by a funeral reimbursement or charitable contribution that conveyed the appreciation of society to the family for their donation. Depending on the amount of reimbursement provided for funeral expenses, this approach could be ethically distinguished from a direct payment, by their intrusion into the realm of altruism and voluntariness. We suggest that a pilot project be conducted to determine whether this kind of a financial incentive would be acceptable to the public and successful in increasing organ donation.

Cadaver↗

The mechanical behavior of locking compression plates compared with dynamic compression plates in a cadaver radius model.

OBJECTIVE: The purpose of this cadaveric study was to compare the mechanical behavior of a locked compression plate, which uses threaded screw heads to create a fixed angle construct, with a dynamic compression plate construct in a cadaver radius model. DESIGN: Mechanical study with cyclic testing and high-speed optical motion analysis. SETTING: Biomechanics laboratory at an academic institution. PATIENTS/PARTICIPANTS: Eighteen pairs of fresh-frozen human cadaver radii were divided into 3 groups of 6 to be tested as a group in each of the following force applications: anteroposterior (AP) bending, mediolateral bending, or torsion. INTERVENTION: Each bone was osteotomized leaving a 5-mm fracture gap and then fixed with a plate. For each pair, 1 radius received a standard plate (limited-contact dynamic compression plates; LC-DCP), the contralateral radius was fixed with a locking compression plate (LCP), and specimens underwent cyclic loading. Normalized stiffness, average energy absorbed, and Newton-cycles to failure were calculated. In addition, a 3-dimensional, high-speed, infrared motion analysis system was used to evaluate motion at the fracture site. MAIN OUTCOME MEASUREMENTS: Construct stiffness, fracture site motion, cycles to failure, and energy absorption. Repeated measures ANOVA were used to detect differences between groups with time. RESULTS: In the torsion group, LCP specimens failed at 60% greater Newton-cycles than the LC-DCP (1473 vs. 918; P < 0.05). In the AP group, the LC-DCP absorbed significantly greater energy during 10,000 cycles compared with the LCP group (P < 0.05). The 2 constructs demonstrated different biomechanical behavior with time. As cycling progressed in the LC-DCP specimens under torsion testing, stiffness (measured at the actuator at the bone ends) did not change significantly; however, fracture motion (measured at the fracture surfaces) decreased significantly (P = 0.04). The LCP specimens did not display similar behavior. CONCLUSIONS: Our findings indicated that LCP constructs may demonstrate subtle mechanical superiority compared with the LC-DCP. The LCP specimens had less energy absorption in the AP group and survived longer in the torsion group. Discordance of motion between measurement regions was observed only in the LC-DCP torsion group, and may have been caused by plate-bone slippage or bone-screw subcatastrophic failure. However, many other compared parameters were found to be similar, and the clinical significance of the few differences found between constructs mandates further investigation.

Biomechanical Phenomena↗

Accuracy of thoracic vertebral body screw placement using standard fluoroscopy, fluoroscopic image guidance, and computed tomographic image guidance: a cadaver study.

STUDY DESIGN: A surgical simulation study in human cadaver spine specimens was conducted to evaluate the accuracy of thoracic vertebral body screw placement using four different intraoperative imaging techniques. OBJECTIVE: To compare standard fluoroscopy, fluoroscopy-based image guidance with two different referencing methods, and computed tomography-based image guidance by the measuring the time required for screw placement, the radiation exposure to specimen and surgeon, and the accuracy of screw position in the thoracic spine. SUMMARY OF BACKGROUND DATA: Image guidance provides additional anatomic information to the surgeon and may improve safety of technically difficult surgical procedures. The placement of screws in the thoracic spine is a technically demanding procedure in which inaccurate screw positioning places the spinal cord, nerve roots, and paraspinal structures such as the aorta and pleural space at risk for injury. Image-guided surgery may improve the accuracy of thoracic screw placement. METHODS: Using four different intraoperative imaging methods, two experienced surgeons placed 337 vertebral body screws through the pedicles of thoracic vertebrae in 20 human cadaver thoracic spine specimens. The specimens then were examined with radiographs, computed tomography, and anatomic dissection to determine screw position. Measurements included procedure setup and screw insertion time, radiation exposure to the specimen, the surgeon's hand, the surgeon's body, frequency, direction, and magnitude of screw perforation through the cortical margins of thoracic vertebrae. RESULTS: As compared with surgery using standard fluoroscopy, fluoroscopy-based image guidance that uses multiple reference marks and computed tomography-based image guidance improves the accuracy of thoracic vertebral body screws, but increases the time required for screw placement and the specimen radiation exposure. Exposure to radiation is minimal at the surgeon's body level and dependent on surgical technique at the surgeon's hand level. Screw perforation occurs most frequently in the lateral direction. CONCLUSIONS: Fluoroscopy-based image guidance that uses only a single reference marker for the entire thoracic spine is highly inaccurate and unsafe. Systems with registration based on the instrumented vertebrae provide more accurate placement of thoracic vertebral body screws than standard fluoroscopy, but expose the patient to more radiation and require more time for screw insertion.

Adult↗

Effect of segmental artery ligation on the blood supply of the thoracic spinal cord during anterior spinal surgery: a quantitative histomorphological fresh cadaver study.

STUDY DESIGN: Human cadaver quantitative morphometric analysis of the blood vessels in the spinal cord after ligation of segmental arteries. OBJECTIVES: To investigate the effect of ligation of segmental arteries on the quantity and density of the blood vessels in the spinal cord. SUMMARY OF BACKGROUND DATA: Ligation of segmental arteries is often used in the anterior approach for correction scoliosis. However, whether or not segmental artery ligation is liable to deny the spinal cord an adequate blood supply, thus leading to paraplegia, still remains controversial. METHODS: Eleven fresh cadavers were divided into control, unilateral, and bilateral groups. For the unilateral and bilateral groups, 5 segmental vertebral arteries (T7-T11) were ligated unilaterally and bilaterally, respectively. Then, the number and density of blood vessels at different levels in the 3 groups were measured. RESULTS: Compared to that of the corresponding level in the control group, the number of blood vessels at T5 to L1 all decreased in the ligation groups. And significant differences were found at T8 (82.80 +/- 16.36), T10 (77.80 +/- 19.80), and T11 (99.20 +/- 14.85) levels, compared to those of the corresponding levels in the control group: T8 (175.80 +/- 8. 31), T9 (176.40 +/- 32. 33), T10 (171.40 +/- 9. 73), and T11 (189.20 +/- 15. 92). Further decrease was found at each corresponding level in the bilateral group, and significant differences were found at T8 (65.80 +/- 15.55), T9 (24.80 +/- 13.43), T10 (0), T11 (0), and T12 (0) levels. Similar results were obtained with regard to the density of blood vessels. Significant differences were found at T11 (1.246 +/- 0.112) and L1 (1.349 +/- 0.109) in the unilateral group, and T9 (0.260 +/- 0.088), T10 (0), T11 (0), T12 (0), and L1 (0.147 +/- 0.117) in the bilateral group compared to those of the corresponding levels in the control group: T9 (1.810 +/- 0.202), T10 (1.833 +/- 0.175), T11 (2.308 +/- 0.335), T12 (2.510 +/- 0.617), and L1 (2.193 +/- 0.033). CONCLUSIONS: This study suggests that the more levels the ligation encompasses, the higher the risk of spinal cord damage. Therefore, caution should be taken when several segmental arteries are to be ligated in the clinical setting. What is more, bilateral ligation, which is worse than unilateral ligation, can lead to a significant decrease in the number and density of blood vessels of the spinal.

Adolescent↗

Corneal endothelial cell damage after lens extraction using the fluid-based system compared to ultrasound phacoemulsification in human cadaver eyes.

PURPOSE: To compare the endothelial cell damage after lens removal using a fluid-based system to conventional ultrasound. METHODS: Twenty human cadaver eyes were randomized to undergo phacoemulsification using either a fluid-based system or conventional ultrasound. After surgery, each corneoscleral button was removed, stained and damaged endothelial cells per square millimeter were assessed using light microscopy. RESULTS: Fluid-based system mean damaged endothelial cells/mm was 60.2 +/- 24.1 compared with 60.4 +/- 42.6 when using conventional ultrasound (P = 0.248). CONCLUSION: The fluid-based system is as safe for the corneal endothelium as conventional ultrasound during cataract removal in human cadaver eyes.

Adult↗

A practical femtosecond laser procedure for DLEK endothelial transplantation: cadaver eye histology and topography.

PURPOSE: The manual dissection technique for deep lamellar endothelial keratoplasty (DLEK) surgery is technically difficult and may not be smooth enough for consistently optimal postoperative vision. We evaluated the feasibility and efficacy of using a femtosecond laser to perform the dissections in the DLEK procedure. METHODS: The Intralase femtosecond laser (with standard LASIK surgery spot settings) was used to create a 9.4-mm wide, 400-microm deep lamellar pocket dissection and a 5.0-mm wide side cut near-exit incision in 10 "recipient" whole cadaver eyes and in 10 "donor" cadaver corneal-scleral caps mounted onto an artificial anterior chamber. Recipient and donor disks were resected with special scissors, and the donor tissue was transplanted using the small incision (5.0-mm) DLEK technique. Topography of the recipient eyes was measured pre- and postlaser dissection, and the recipient and donor tissues were sent for scanning electron microscopy (SEM) analysis of the smoothness of the dissections. RESULTS: Successful lamellar dissections were obtained in all tissues. The mean recipient topographic corneal curvature postoperatively was 43.3 +/- 1.7 diopters, which was not a significant change from the preoperative curvature of 44.0 +/- 0.8 diopters (P = 0.430). The mean recipient topographic astigmatism postoperatively was 1.7 +/- 0.8 diopters, which was not a significant change from the preoperative recipient astigmatism of 1.6 +/- 0.7 diopters (P = 0.426). Comparison of the histology of the laser-formed stromal dissections by scanning electron microscopy, however, did not appear significantly better than histology after manual DLEK dissections in either the recipient or the donor tissues. CONCLUSIONS: A femtosecond laser can create the lamellar dissections for the DLEK procedure, making this procedure easier and faster. As in the manual technique, corneal topography is unchanged by this surgery. More work will need to be done, however, to optimize the laser settings to provide even smoother interface surfaces.

Astigmatism↗

The sphenozygomatic suture as a key site for osteosynthesis of the orbitozygomatic complex in panfacial fractures: a biomechanical study in human cadavers based on clinical practice.

The aims of this study were to determine the forces required for fracturing the intact orbitozygomatic complex and to evaluate the strength of the orbitozygomatic complex-fixation, especially with regard to the sphenozygomatic suture as a fixation point. In severe midfacial and panfacial fractures, the sphenozygomatic suture is routinely used in the authors' practice as a key site for fixation of the orbitozygomatic complex, thus establishing a stable outer frame as a basis for subsequent reconstruction. However, this has never been formally described, nor has it been biomechanically tested. Eight human cadaver heads were subjected to forces applied in a standard fashion to the orbitozygomatic complex on both sides (n = 16) using a servohydraulic testing machine. The force required to break the intact orbitozygomatic complex was measured on both sides. Subsequently, fracture patterns were noted and each orbitozygomatic complex (n = 16) was assigned to one of four groups: four-point fixation (zygomatic arch, frontozygomatic suture, infraorbital rim, zygomaticomaxillary buttress) using a 1.3/2.0-mm titanium system (group 1) and a 2.0-mm bioresorbable system (group 3); or three-point fixation (zygomatic arch, frontozygomatic suture, sphenozygomatic suture) using 1.3/2.0-mm titanium system (group 2) and a 2.0-mm bioresorbable system (group 4). Forces for failure of the constructs were measured. The force for failure of the intact orbitozygomatic complex was 1826 +/- 852 N. The mean force required for failure of the reconstructed orbitozygomatic complex was 504 +/- 178 N for group 1, 620 +/- 304 N for group 2, 93 +/- 22 N for group 3, and 133 +/- 31 N for group 4. The titanium constructs provided 27.7 percent (four-point fixation) and 31.7 percent (three-point fixation) of the intact breaking strength of the orbitozygomatic complex, which was significantly higher (p < 0.05) compared with 5.4 percent (four-point fixation) and 7.7 percent (four-point fixation) for the bioresorbable system. Plate bending (91 percent) was the primary cause for failure in the titanium plating system, whereas plate and screw breakage (57 percent) was responsible for failure of the resorbable system. The fixation of the sphenozygomatic suture was a key site in the fixation of the orbitozygomatic complex, which could be demonstrated with superior results in the three-point fixation group compared with the four-point fixation group. The bioresorbable system showed the lowest values in this cadaver study. Further experimental and clinical studies might determine whether the bioresorbable materials are sufficient for the treatment of complex fractures of the orbitozygomatic complex.

Absorbable Implants↗

A cadaver study in preparation for facial allograft transplantation in humans: part I. What are alternative sources for total facial defect coverage?

BACKGROUND: Reconstruction of facial defects in burn, trauma, and head-neck cancer patients is challenging. The lack of autogenous tissue availability and the need to match facial texture and color are major concerns. METHODS: Anatomical dissections were performed to search for alternative sources for facial-scalp reconstructions in five cadavers. The composite facial-scalp flaps, radial forearm, anterolateral thigh, bipedicled deep inferior epigastric perforator, and bipedicled scapular-parascapular flaps were harvested. The total surface areas of the facial defects and alternative traditional flaps were measured. RESULTS: The mean surface area for combined facial-scalp flaps and facial flaps without scalp was 1192 +/- 38.2 cm and 675 +/- 22.3 cm, respectively. When compared with the total surface area of the facial-scalp flap, it was found that the radial forearm flap covered 13 +/- 2.58 percent, the anterolateral thigh flap 19 +/- 3.72 percent, the bipedicled deep inferior epigastric perforator flap 35 +/- 1.56 percent, and the bipedicled scapular-parascapular flap 48 +/- 4.64 percent of the defect, respectively. When measurements were taken for coverage of the facial defect without scalp, it was found that the radial forearm flap covered 24 +/- 4.0 percent, the anterolateral thigh flap 34 +/- 6.50 percent, the bipedicled deep inferior epigastric perforator flap 62 +/- 3.03 percent, and the bipedicled scapular-parascapular flap 84 +/- 8.30 percent of the defect, respectively. CONCLUSIONS: The authors' cadaver dissection confirmed that none of the conventional cutaneous autogenous flaps are able to cover total facial defects. Currently, the best option for reconstruction of the full facial defect is the autogenous bipedicled scapular-parascapular flap because of its large size and texture. However, perfect match of facial skin texture, pliability, and color can only be achieved by transplantation of the facial skin allograft from the human donor.

Aged↗

3D versus 2D ultrasound: accuracy of volume measurement in human cadaver kidneys.

RATIONALE AND OBJECTIVES: Comparison of the accuracy of 3D and 2D ultrasound in assessing the volume of human cadaver kidneys. MATERIALS AND METHODS: Before autopsy the volume of 22 kidneys was assessed from a 3D data set after manually tracing organ contours (3D volumetry) and by applying a 3D ellipsoid formula both on a 3D data set and 2D images. Measurements by water-displacement served as the gold standard. RESULTS: 3D volumetry showed a mean absolute deviation of 31 mL (18.5%) compared with the mean gold standard measurement (168 mL), yielding a concordance correlation (Lin's rho(c) ) of 0.71. Calculation based on the ellipsoid formula revealed a mean absolute deviation of 37 mL (22.0%) when applied on the 3D data set (rho(c) = 0.65) and of 42 mL (25.0%) when applied on 2D images (rho(c) = 0.61). CONCLUSIONS: 3D volumetry showed a satisfactory concordance correlation and is superior to volume calculation based on the ellipsoid formula either applied to a 3D data set or to conventional 2D images in assessing the volume of human cadaver kidneys.

Aged↗

A new epitope-based HLA-DPB matching approach for cadaver kidney retransplants.

BACKGROUND: Several years ago a significant impact of matching for HLA-DPB1 alleles on the survival of cadaver kidney retransplants was shown. Here we report the results of a new approach, based on matching for HLA-DPB1 epitopes. METHODS: The analysis is based on 1,478 patients who received a cadaver kidney retransplant between 1988 and 1998. DNA methodology (polymerase chain reaction, sequence-specific oligonucleotides) was used to perform HLA-DPB1 typing. Epitope matching was facilitated with the aid of sequence databases and computer calculations. RESULTS: Matching for the HLA-DP epitopes A, B, E, and F, corresponding to the homonymous hypervariable regions of the second exon of the DPB1 gene, seems to have a greater influence on graft survival than matching for the epitopes C and D. Within a group of 529 retransplants with exactly one allelic HLA-DPB1 mismatch, a significantly better graft outcome was observed when less than two epitope mismatches were found, compared with the group with more than three epitope mismatches (at 2 years: 77.8% vs. 65.8%, P=0.0112). Importantly, patients with two DPB1 allele mismatches who had less than or equal to two epitope mismatches exhibited a significantly better graft outcome than recipients who had one HLA-DPB1 allelic mismatch but more than three epitope mismatches (at 2 years: 77.1% vs. 65.8%, P=0.0488). CONCLUSIONS: The findings indicate that the impact of HLA-DPB1 matching on the outcome of kidney retransplants is a result of the predominant immunogenicity of certain epitopes of the HLA-DP molecule. Matching for immunogenic HLA-DPB1 epitopes seems to be functionally more relevant than classical matching at the allelic level.

Cadaver↗

Elimination of false-negative hepatitis C virus RNA results by removal of inhibitors in cadaver-organ donor blood specimens.

Detection of viral nucleic acids in blood samples from cadavers is often difficult because of inhibition of the reverse transcriptase (RT) or polymerase chain reaction (PCR) steps by substances present in the samples. A robust method for the extraction and detection of hepatitis C virus (HCV) RNA from cadaver blood samples by polymerase chain reaction RT-PCR has been developed on the basis of the Qiagen QIAamp DNA mini kit extraction system (Basel, Switzerland). Twenty of 36 samples tested were positive for HCV RNA. Six of the 16 HCV-antibody- and RNA-negative samples contained inhibitors that were successfully removed by pretreatment of samples with the Qiagen AX matrix before extraction.

Cadaver↗