Viability of crushed and diced cartilage grafts: a study in rabbits

OBJECTIVE: To investigate the effects of dicing and different degrees of crushing on cartilage graft viability and outcome in rhinoplasty. METHODS: Cartilage was harvested from both ears of 29 rabbits. For each animal, 6 cartilage pieces were prepared as follows and inserted into the paraspinal subcutaneous tissue: (1) left intact, (2) diced to approximately 1 x 1-mm pieces and then wrapped in oxidized regenerated cellulose, (3) slightly crushed, (4) moderately crushed, (5) significantly crushed, and (6) severely crushed. Animals were killed at 2, 5, and 10 months, and graft specimens were microscopically examined. RESULTS: As crushing intensity rose, cartilage viability decreased and more cartilage tissue was transformed to connective tissue. The intact and slightly crushed grafts showed significant chondrocyte proliferation. This decreased as crushing intensity increased, and the severely crushed and diced cellulose-wrapped grafts exhibited almost no peripheral chondrocyte proliferation. CONCLUSIONS: Slight crushing of a cartilage graft can produce outstanding graft material that forms softer nasal contours and fills defects well. However, severe crushing of cartilage grafts results in extensive necrosis and eventual reduction in graft volume. The use of oxidized regenerated cellulose to wrap diced cartilage grafts also tends to reduce clinical predictability owing to negative effects on cartilage viability and regeneration.     

Viability of cultured human nasal septum chondrocytes after crushing

OBJECTIVE: To investigate how different degrees of crushing affect the viability of human nasal septum chondrocytes in adherent cell cultures. METHODS: Cartilage grafts were harvested from the nasal septa of 15 patients who underwent submucosal resection. Five cartilage pieces were prepared from each specimen as follows: the cartilage was left intact, slightly crushed, moderately crushed, significantly crushed, or severely crushed. Chondrocytes were isolated for trypan blue dye exclusion testing, and the numbers of viable cells were determined at 1, 2, 3, and 10 days after culturing. Comparisons were made among the groups. RESULTS: The day 1 viability rates for the intact, slightly crushed, moderately crushed, significantly crushed, and severely crushed cartilage preparations were 96%, 92%, 82%, 72%, and 54%, respectively. The corresponding rates on day 10 were 93%, 90%, 84%, 75%, and 68%. CONCLUSIONS: The viability and proliferative capacity of crushed human septal cartilage depend on the degree of crushing sustained. Slightly or moderately crushed cartilage grafts show good chondrocyte viability and proliferation and are valuable for fashioning soft nasal contours, filling defects, and concealing dorsal irregularities. However, significant or severe crushing reduces chondrocyte viability and proliferation and may result in unpredictable degrees of graft volume loss.     

Use of Septal Cartilage Homografts in Rhinoplasty

We present a case report demonstrating the long-term survival of homologous cartilage grafts in the nose. There are no histological changes in homografts compared with autologous cartilage. The importance of an adequate technique of preservation as well as the possibility of viral transmission, are discussed. In our opinion, septal cartilage is the best reason for nasal repair, before auricular or costal cartilages. We consider the use of homologous septal cartilage a useful technique basically indicated when a cartilage graft is considered necessary, but there is insufficient autologous cartilage available.     

Dorsal nasal augmentation with "open sandwich" graft consisting of conchal cartilage and retroauricular fascia

Background: Augmenting the nasal dorsum with conchal grafts can cause visible irregularities over time due to the morphological qualities of that material. Objectives: This study describes the senior authors' technique of dorsal nasal augmentation with chondrofascial "open sandwich" grafts consisting of pieces of conchal cartilage and retroauricular fascia. The authors assess the efficiency and reliability of this graft in nasal dorsal augmentation. Methods: The authors retrospectively reviewed the cases of 19 patients who underwent dorsal augmentation rhinoplasty with chondrofascial grafts. Both cartilage and fascia were harvested through the same incision in the retroauricular sulcus. The conchal graft was cut in 2 to 4 pieces and slightly crushed with tissue forceps. The pieces of cartilage were arranged and fixed to the fascia in different patterns according to the nasal dorsum contour. Results: The follow-up period ranged from 12 to 35 months in 16 patients who qualified for inclusion in the final data. The maximal thickness of the chondrofascial graft was 4.5 mm. There were no major complications in the recipient area, except 1 case of undercorrection. There were 2 complications in the donor area. In 1 case, a hematoma was treated conservatively. In another case, a strip of skin necrosis in the conchal area occurred and was treated by excision and direct suture with satisfactory resolution. Conclusions: The autologous chondrofascial graft is appropriate for slight to mild dorsal nasal augmentation. The method, as with most rhinoplasty techniques, requires careful and judicious preoperative examination, planning, and execution. The postoperative scar is inconspicuous and the donor site morbidity is minimal. Level of Evidence: 4.     

The use of preserved autogenous septal cartilage in "touch-up" rhinoplasty

The management of minor contour irregularities after primary aesthetic rhinoplasty often requires correction of soft tissue defects with autogenous cartilage, allograft materials, xenograft matrix, or alloplasts. Inasmuch as the use of native cartilage requires an additional procedure (and potential donor site morbidity) and alloplast insertion raises the specter of extrusion or cicatrical deformity, the use of preserved autogenous cartilage is an attractive alternative, particularly for minor revision surgery. This study describes the experience and technique of the senior author (P.F.G.) with the use of isopropyl alcohol-preserved autogenous nasal cartilage during revision rhinoplasty in which only minor contour correction is required. When grafts are needed for revision surgery, they are inserted via small intranasal stab incisions into minor irregularities of the tip, alae, and dorsum. This technique eliminates the need for additional surgery to obtain graft material, reduces costs and risks associated with alloplasts, and is particularly useful for minor revision rhinoplasty. Office-based techniques for preserving cartilage are reviewed.     

Chondrocyte viability in press-fit cryopreserved osteochondral allografts.

The viability of chondrocytes in press-fit glycerol-preserved osteochondral allografts was compared to that in fresh autografts, after transplantation into load-bearing and non-load-bearing sites in mature sheep stifle joints. We used macroscopic grading, tonometer pen indentation testing, histology, sulfate uptake and viability as determined by confocal-microscopy to assess cartilage condition. Despite there being no statistical differences between macroscopic appearance and tonometer testing of all grafts, confocal microscopy and histology demonstrated a positive effect of load-bearing placement on cryopreserved osteochondral allografts. Allografts transplanted into load-bearing sites demonstrated superior confocal microscopy-measured chondrocyte viability (77%+/-17%SD) than those transplanted into non-load-bearing sites (25%+/-2%). Load-bearing effect was not seen in autografts (78%+/-15%), and was comparable in adjacent cartilage (83%+/-9%). Similarly, load-bearing allografts demonstrated histological scoring closer to that of autografts and adjacent cartilage, all of which fared significantly better than non-load-bearing allografts. Load-bearing allografts had a greater amount of fibrocartilage than autografts or adjacent cartilage but less fibrocartilage than non-load-bearing allografts. Both autografts and allografts had non-significant increases in metabolism compared to adjacent cartilage as measured by sulfate-uptake. Load-bearing placement improved chondrocyte viability of glycerol cryopreserved osteochondral allograft following a press-fit implantation.     

反复冻融及超深低温处理的异体肌腱移植实验研究

为比较有创与无创冷冻方法处理的肌腱异体移植的效果，探索不同冷冻处理技术对肌腱免疫源性的影响及获得成功的异体移植的条件，采用有创反复冻融及无创超深低温（－１９６℃）冻存技术分别处理肌腱，液氮下保存３个月后异体移植，以自体肌腱移植作对照。腱细胞活力测定显示，反复冻融处理的肌腱细胞全部失活，而超深低温处理的肌腱细胞活力为（９２．５±３．４）％。组织学观察显示，反复冻融及超深低温处理的异体移植肌腱均产生了不同程度炎性细胞浸润，且腱周粘连均较自体移植肌腱重。主动屈曲功能测定、羟脯氨酸含量测定及生物力学性能测定显示，反复冻融与超深低温组无显著性差异（Ｐ＞０．０５），且后两项指标显著较自体移植肌腱差。认为：①反复冻融及超深低温处理的肌腱异体移植获得一定成功，两者无显著性意义。②既要保留肌腱细胞的活性，又要去除肌腱中的抗原呈递细胞，可能是冷冻处理的肌腱异体移植获得成功的关键。③损伤了肌腱细胞成分，降低了肌腱抗原性，不等于能获得成功的异体移植     

自体真皮脂肪复合组织块移植修复鼻背塌陷

目的 探讨自体真皮脂肪复合组织块在鼻背塌陷修复中作为填充材料的可行性、科学性及修复效果.方法 切取自体臀部或腹部真皮脂肪复合组织块（7.0 cm×1.0 cm×1.0 cm）,作为填充材料,对13例鼻背塌陷、鼻形不良者进行修复,酌情配合耳廓软骨加真皮脂肪复合组织块的伞状移植物,重塑鼻背、鼻尖的良好形态.结果 13例鼻背塌陷者,进行鼻背、鼻尖修复后,真皮脂肪复合组织块存活良好,切口均Ⅰ期愈合,且切口痕迹不明显.经1年随访,鼻外形改善、满意.结论 以自体真皮脂肪复合组织块或结合耳廓软骨移植修复鼻背塌陷,效果满意,且取材方便、无排异反应等,患者易于接受.     

Cartilage implantation in head and neck surgery: report of a national survey

As enthusiasm for alloplastic grafts wanes, the use of biologic materials for reconstructive and aesthetic surgery is regaining popularity. A plethora of methods exists for preservation of one of the most popular implants, human cartilage. The controversy over the efficacy of autologous v preserved homologous cartilage grafts continues. A national study was developed to determine the efficacy of autologous v the various techniques of cartilage preservation based on the criteria of graft extrusion, infection, and absorption. Autologous grafts were most commonly used. The most popular preservation methods used alcohol or merthiolate. Autologous grafts had less absorption than preserved grafts, but both groups had approximately equivalent infection and extrusion rates. Irradiated cartilage showed the least absorption of all preservation methods.     

Augmentation of the nasal dorsum with autogenous costal cartilage using the "edge-on" technique

Carved costal cartilage autografts are commonly used for nasal augmentation in saddle nose deformities. One major disadvantage of these carved grafts is postoperative warping. To prevent warping of costal cartilages, we used the "edge-on" technique. The inferior border of the cartilage is rotated 90 degrees to become the convex dorsum. No cartilage is trimmed or carved, and hence the intrinsic stress forces within the graft are not disturbed. The results in 21 patients are documented with long-term follow up (mean, 4 years) and showed no evidence of warping. Other complications, advantages, and disadvantages of the technique are discussed.     

Viability of fresh aortic valve homografts: a quantitative assessment

Accumulated evidence indicates that fresh aortic valve homografts function longer than preserved grafts. Thus it becomes important to assess the viability of fresh homografts on a quantitative basis. Recently, we have used autoradiography in addition to tissue culture to determine the viability of fresh aortic and pulmonary valve homografts. The uptake of thymidine was gradually reduced to 50% after 18 days of preservation in a balanced salt solution with antibiotics and the uptake was reduced to 21% in 63 days. We think that a nutrient medium is necessary if longer viability is to be obtained.     

自体肋软骨移植构建鼻尖软骨复合体在鼻整形中的临床应用

目的：通过应用自体肋软骨重塑鼻尖软骨支架结构,形成稳定的鼻尖软骨复合体,来达到完美、立体的鼻尖外形,同时应用膨体聚四氟乙烯或硅胶假体支架抬高鼻背,从而达到理想的鼻部整形美容效果。方法：以鼻小柱基底部＂几＂字形切口和鼻孔内鼻翼软骨外侧缘切口,彻底分离皮肤达鼻翼基底部,对鼻尖短小朝天者可松解到达梨状孔边缘,显露两侧鼻翼软骨及侧鼻软骨,同时暴露鼻中隔软骨游离端;雕刻自体肋软骨,移植、固定到鼻中隔软骨上,贯穿缝合鼻翼软骨、移植的软骨,形成鼻尖软骨支架结构,构建鼻尖软骨复合体。雕刻膨体聚四氟乙烯或硅胶假体支架放置到鼻背鼻骨骨膜下抬高鼻背。结果：本组96例手术者均采用自体肋软骨移植构建鼻尖软骨复合体行鼻整形,术后7天拆线,切口Ⅰ/甲愈合。随诊6～12个月,95例术后鼻尖表现点明显,鼻形立体、挺拔,自然美观,鼻尖活动度好,效果满意。1例术者感觉鼻小柱下垂,通过修复移植软骨,达到满意效果。结论：应用自体肋软骨重塑鼻尖软骨支架结构,构建鼻尖软骨复合体,同时应用膨体聚四氟乙烯或硅胶假体支架抬高鼻背,可以达到理想的鼻部整形美容效果。     

Freeze-dried allogeneic segmental cortical-bone grafts in dogs.

Forty-four adult male mongrel dogs were used to compare segmental cortical freeze-dried allogeneic bone grafts with fresh autogenous, freeze-dried autogenous, and fresh allogeneic segmental cortical grafts. Group I consisted of bilateral fresh autografts as external controls; Group II, a fresh autograft on one side for internal control and a freeze-dried autogenous graft on the other side to evaluate the effect of freeze-drying on repair; Group III, a fresh autograft on one side and a fresh allograft on the other side to measure the differences between autogenous and allogeneic grafts; and Group IV, a fresh autograft on one side and a freeze-dried allogeneic graft on the other to see if freeze-drying altered the repair of allogeneic grafts. The grafts were analyzed qualitatively over a six-month period by the use of interval roentgenograms to determine the times of graft-host union and the incidence of fatigue fractures. Six months after operation, the repair processes in the four groups were compared quantitatively with respect to biological repair and physical strength using torsional stress-testing, tetracycline labeling, and microradiography. The results indicate both qualitatively and quantitatively that: (1) fresh bilateral segmental cortical autografts show reproducible characteristics, so that the canine fibula furnishes a satisfactory model (Group I); (2) freeze-drying does not inhibit the repair process per se (Group II); (3) fresh allografts are rejected in varying degrees of intensity (Group III); and (4) freeze-drying does not protect cortical allogeneic grafts from such rejection (Group IV).     

Use of Autologous Costal Cartilage Combined with Expanded Polytetrafluoroethylene in Asian Rhinoplasty

BackgroundThe corresponding author's experience and recent methods employed in autologous costal cartilage grafts combined with expanded polytetrafluoroethylene (ePTFE) in Asian rhinoplasty were presented in this study.ObjectivesThe purpose of this study was to assess the outcomes of rhinoplasty performed on patients using autogenous costal cartilage grafts combined with an ePTFE implant.MethodsSeventy-five rhinoplasty cases with autologous costal cartilage grafts and an ePTFE implant were retrospectively reviewed. Graft types, complications associated with the graft itself or graft harvesting, surgical outcomes, and patient satisfaction were assessed.ResultsThe mean follow-up time post-operation was 13.5 months. A total of 42/75 patients underwent revision surgeries. Graft-related complications were found in 8% of cases, including two warped graft and four infection cases. Three individuals with infections had mild graft resorption. One patient with an infection removed the implant. Graft exposure, mobility, and substantial resorption were not recorded. A total of two cases underwent revision procedures for infection and perforation, respectively. Chest incision lengths for graft harvesting averaged 2.1 cm. No pneumothorax or significant donor-site pain was found. Donor-site scars were negligible, although two cases had hypertrophic chest scars. In general, functional and esthetic outcomes were mostly satisfactory among the assessed patients.ConclusionsRhinoplasty using autologous rib cartilage provides adequate support and sufficient cartilage amounts for correcting nasal contouring. Meanwhile, ePTFE alone for nasal dorsum augmentation safely achieves satisfactory outcomes. Rib cartilage rhinoplasty performed by an experienced surgeon yields excellent, long-lasting results with minimal risk; however, the potential for infection should be considered following revision surgery.     

Clinical results of osteochondral allografts in the treatment of osteochondral defects

There have been very few clinical reports on osteochondral allograft in Japan. In the allograft we did for osteochondral defects of the knee, seven fresh grafts and four frozen grafts were used. In six of the seven fresh grafts, the surface presented macroscopically and/or arthroscopically the appearance of almost complete normality. From the histological study of the cartilage for biopsy which was obtained from the fresh graft at postoperative fifteen months, the cell viability, though decreased in the superficial layer, was fairly normal and profusely produced proteoglycan stained with safranin-O in both the middle and the deep layers. The cell viability, however, was decreased remarkably or disappeared in all three layers in the biopsy cartilage taken from the frozen graft at over one year postoperatively. The eight of the eleven knees treated with the osteochondral allograft have preserved the joint space on one foot standing radiogram and revealed good function clinically.     

提高自体软骨移植物活性的研究进展

软骨移植物主要包括自体软骨、同种异体软骨、冷冻同种胚胎软骨、骨膜、软骨膜和生物材料等。但软骨移植存在许多缺陷,如供区继发性病变、进行性供区结构异常、移植物弯曲变形,移植物吸收与存活等问题。本文就提高自体软骨移植物活性的方法,包括软骨碎片或颗粒移植和包裹技术等进行综述。     

Multilayer costal grafts to prevent cartilage deformation: an experimental study

Background

Cartilage grafting is a common procedure in nasal reconstruction or dorsal augmentation. Costal cartilage is usually preferred to conchal or septal cartilage when a larger amount of graft is required, although this cartilage type is often complicated by postoperative warping. To overcome this complication, we suggest the use of multilayer costal grafts. This study aims to compare single-layer and multilayer costal grafts concerning angle of warpage, cartilage viability, and architectural changes in the animal model.

Methods

Twelve costal grafts were harvested from a fresh Landrace pig cadaver; six were shaped in single-layer grafts and six into a multilayer structure, both having the same thickness. These grafts were implanted in subcutaneous dorsal skin pockets of six athymic nude rats. After 8 weeks, the animals were euthanized and the grafts removed. Pictures of the cartilages were acquired. The samples were processed and stained for histological (hematoxylin and eosin, Alcian blue, Von Kossa, Masson-Goldner trichrome, and Verhoeff/Van Gieson stains) and immunohistochemical (GFAP) analyses.

Results

A higher grade of deformation was observed in the single-layer group compared to the multilayer one (5.2° vs 0.3°). Multilayer cartilage showed significantly higher chondrocyte density (70.4 vs 44.9 cells per field at 40×) and the lowest loss of nuclei in chondrocyte lacunae percentage (0.03 vs 3.2 %). Single-layer grafts also showed sporadic inflammatory cell infiltration, not found in multilayer ones.

Conclusions

Multilayer grafts showed a decreased degree of warping as well as an increased viability and should be considered as a valuable alternative in nasal reconstruction.Level of evidence: Not ratable

     

自体肋软骨移植构建鼻尖软骨复合体在鼻整形手术中的美学效果

目的 探究鼻整形手术中鼻尖软骨复合体采用自体肋软骨移植构建的美学效果。方法 选取2022年 7月-2023年7月于我院进行鼻整形的患者169例,按照随机数字表法分为A、B两组,A组84例,B组85例。 A组构建鼻尖软骨复合体时使用膨体聚四氟乙烯材料,B组使用自体肋软骨材料,比较两组外观满意度、鼻 唇角、鼻面角、额鼻角及鼻背高度测量值。结果 B组外观满意度为87.06%,高于A组的57.14%（P＜0.05）;两 组治疗后鼻唇角、鼻面角、额鼻角均高于治疗前,且B组高于A组（P ＜0.05）;两组治疗后鼻背高度均高 于治疗前（P ＜0.05）,但两组治疗后鼻背高度比较,差异无统计学意义（P ＞0.05）。结论 鼻整形手术中 鼻尖软骨复合体采用自体肋软骨移植构建可提升外观满意度,增加鼻唇角、鼻面角、额鼻角及鼻背高度。     

Long-term results of ventricular assist pumping in postcardiotomy cardiogenic shock

A series of experiments were conducted to assess the possibility of revascularizing tracheal homografts with an omental pedicle flap. Three different experiments were performed. In Group I (N = 4) a ten-ring tracheal allograft was embedded into the greater omentum of a recipient animal for 30 days. At reexploration these four allografts were found to have been transformed into a tube consisting mainly of connective tissue. To provide more collateral circulation, we immediately reanastomosed an eight-ring tracheal autograft in Group II animals (N = 7). Collateral blood supply was possibly available from the surrounding mediastinal tissues, the recipient trachea, and the transposed omental graft. Tracheal malacia and loss of rings 4,5, and 6 was a consistent finding and cause of death. A third group of animals (Group III) underwent a similar operation with the addition of free bone grafts being applied to the external surface of the autograft to impede significant tracheal stenosis. The long-term results and the findings when the animals were put to death were the same as in Group II. We conclude that the omental pedicle graft cannot sustain chondrocyte viability. Thus a reliable method for revascularization of a tracheal transplant remains to be found.     

Augmentation Rhinoplasty with Autologous Grafts

The authors present their experience with nasal reconstructive surgery using autologous grafts. Currently, grafts are classified into four categories: skin grafts, cartilage grafts, bone grafts, and composite grafts (Table 1). A sample of 132 patients with nasal defects requiring reconstruction was selected. Two cases, presenting nasal valve collapse and deformities after aesthetic nasal surgery, were analyzed in detail. Overall, satisfying aesthetic results (balanced tip projection, dorsum fullness, widening of internal nasal valve angle, minor scar retraction) were achieved for both patient and surgeon in 79% of the cases.