Orthopedic Biomechanics Laboratory, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
Spine (Phila Pa 1976). 2010 Jan 15;35(2):153-61. doi: 10.1097/BRS.0b013e3181c4b8c7.
Using a rabbit model of postnatal pulmonary hypoplasia, we investigated how expansion thoracoplasty affected growth of the spine and lungs.
By constricting the hemithorax in a growing rabbit to create postnatal pulmonary hypoplasia, we quantified how expansion thoracoplasty affects lung volume, respiratory function, alveolar morphology, and spine growth.
In children with thoracic insufficiency syndrome, expansion thoracoplasty of the constricted hemithorax improves respiratory function and controls scoliosis. We hypothesize that expansion thoracoplasty of the constricted hemithorax improves pulmonary hypoplasia by allowing the lung to expand, improving respiratory function and stimulating lung growth.
Postnatal pulmonary hypoplasia and scoliosis were induced in 5-week old rabbits by constricting left ribs 3 to 8. Expansion thoracoplasty through the fused ribs was performed at 10 weeks. These were compared with Disease rabbits allowed to grow with a constricted left hemithorax and Normal rabbits. Spine and thoracic deformity, right and left lung volumes were measured on reconstructed 3-dimensional computed tomography images and functional residual capacity measured by plethysmography. At maturity, lungs were excised and quantitative histology performed to measure alveolar air fraction and surface density.
Expansion thoracoplasty of the constricted left hemithorax improved scoliosis but increased left lung volumes only moderately compared with Disease rabbits. For Disease and Thoracoplasty Treated rabbits, a compensatory increase in the volume of the right lung maintained total lung volumes equivalent to Normal. Alveolar air space fraction was greater in Disease rabbits, suggestive of emphysema improved by expansion thoracoplasty. Capillaries adjacent to the alveoli were prominent in Thoracoplasty Treated rabbits.
Expansion thoracoplasty reduces scoliosis and increases the volume of the constricted hemithorax, but the relative increase in the ipsilateral lung volume is small since compensatory hypertrophy of the contralateral lung also occurred. Expansion thoracoplasty may improve respiratory function by increasing alveolar capillaries and preventing emphysematous changes.
我们使用一种新生后肺发育不全的兔模型，研究扩张性胸廓成形术对脊柱和肺生长的影响。
通过对生长中的兔单侧胸廓进行限制，制造新生后肺发育不全模型，我们量化了扩张性胸廓成形术对肺容量、呼吸功能、肺泡形态和脊柱生长的影响。
在胸廓发育不全综合征患儿中，对受限的半胸廓进行扩张性胸廓成形术可改善呼吸功能并控制脊柱侧凸。我们假设对受限的半胸廓进行扩张性胸廓成形术可通过允许肺扩张来改善肺发育不全，从而改善呼吸功能并刺激肺生长。
通过限制第 3 至 8 肋骨，在 5 周龄的兔中诱导新生后肺发育不全和脊柱侧凸。在 10 周时通过融合肋骨进行扩张性胸廓成形术。将其与允许左半胸廓受限生长的疾病兔和正常兔进行比较。通过重建的 3 维 CT 图像测量脊柱和胸廓畸形、右肺和左肺容积，通过体积描记法测量功能残气量。在成熟时，切除肺并进行定量组织学检查以测量肺泡空气分数和表面密度。
与疾病兔相比，限制左侧胸廓的扩张性胸廓成形术改善了脊柱侧凸，但仅适度增加了左肺容积。对于疾病兔和胸廓成形术治疗兔，右肺体积的代偿性增加维持了与正常兔相当的总肺容积。疾病兔的肺泡空气分数更大，提示扩张性胸廓成形术改善了肺气肿。与疾病兔相比，胸廓成形术治疗兔的肺泡旁毛细血管更为明显。
扩张性胸廓成形术可减少脊柱侧凸并增加限制的半胸廓体积，但由于对侧肺的代偿性肥大也发生，因此同侧肺体积的相对增加较小。扩张性胸廓成形术可能通过增加肺泡毛细血管和防止肺气肿样改变来改善呼吸功能。
