Study Of The Respiratory System Change After Phrenic Nerve Transfer In Children

Part 1 The influence of the respiratory system after unilateral phrenectomy in pigletsObjective To investigate the different influence of the respiratory system following unilateral phrenectomy in piglets of different ages.Methods 36 piglets were divided into three groups according to operational age(10d,30d,50d). In each group six piglets underwent left cervical phrenectomy and six piglets were sham-operated controls.Pulmonary functions , artery blood gas analysis and chest fluoroscopy were performed postoperatively and 3 months old. Pulmonary function parameters include respiratory rate (RR) , tidal volume (V_Tins) , minute ventilation (MV),dynamic compliance (C_dyn), and airway resistance (R_aw,). Artery blood gas analysis the pH,PaO₂, PaC0₂, SaO₂At the age of 3 months old lungs were fixed in situ with 4% formaldehyde by airway installation at 10 cmH₂0. Lung tissue was cut from lung corresponding to the four quadrant (RUQ, RLQ, LUQ, LLQ) and prepared for light microscopy. Morphometry involved diameter of alveolus (D_a)and density of alveolar septum (D_s).Results Compared to the control groups , dynamic compliance(C_dyn) decreased and airway resistance(R_?w) increased postoperatively in the piglets operated on 10d and 30d at the age of 3 months old (P<0.05). Density of alveolar septum (Ds) increased and diameter of alveolus (Da) decreased noticeably in the piglets groups which underwent cervical phrenectomy at 10d and 30d (P<0.05) . However there was no obvious change happened in the group operated at 50d (P>0.05).Conclusions Unilateral phrenectomy in piglets of less than 30d old may cause abnormity of respiratory system .The younger the piglet, the more serious consequences of the operation. Piglets older than 50dtolerate the operation better and may not lead to respiratory dysfunction for long follow-up.R651. 3Part 2 The influence of the expression levelsof epidermal growth factor (EGF) and Keratinocyte growthfactor (KGF) following unilateral phrenectomy in pigletsObjective To investigate the different influence of the expression levels of epidermal growth factor (EGF) and Keratinocyte growth factor (KGF) following unilateral phrenectomy in piglets of different ages.Methods 36 piglets were divided into three groups according to operational age(10d,30d, 50d). In each group six piglets underwent left cervical phrenectomy and six piglets were sham-operated controls. The expression levels of EGF and KGF were determined by real time quantitative reverse transcription-polymerase chain reaction(RT-PCR) after 2 weeks of the operation.Results Compared to the control groups , the expression levels of EGF and KGF decreased postoperatively in the piglets operated on 10d and 30d (P<.0.05). However there was no obvious change happened in the group operated at 50d (P>0.05). The expression levels of EGF and KGF were decreased with the lung development of piglets (P<0.05) .Conclusions Unilateral phrenectomy in piglets less than 30d old may cause abnormity of the EGF and KGF expression levels. Piglets older than 50d may not lead to significant influnce.R651. 3Part 3 The change of the respiratory system after transfer of phrenic nerve in children forlong follow-up studies.Objective To study the changes of the respiratory system in children after transfer of the phrenic nerve for a long period so that we can determine the safe time of the operation.Methods Between March 1998 and April 2001, a total of thirty-four children with brachial plexus avulsion injurys (ABPI) underwent phrenic nerve transfer. The ABPI was a result of obstetric brachial plexus palsy (OBPP) in 27 patients, machine traction in 3 patients, traffic accident in 2 patients, and falling in the other 2 patients. The children were followed up for an average of 4. 03(3⁷) years. They were divided into three groups according to the age at operations (0～12,13～36, 37～60 months old), and paired with the normal children( height, weight and gender).Examinations consisted of postoperative daily clinical syndrome, chest fluoroscopy, artery blood gas analysis (PH, PaC0₂, PaO₂), and pulmonary function. Pulmonary functional parameters including tidal volume (VT/kg), time taken to reach peak expiratory flow to total expiratory time (TPTEF/TE), volume taken to reach peak expiratory flow to total expiratory volume(VPEF/VE), airway resistance Rrs5 (R5), reactance Xrs5(X5), vital capacity max (VCMAX) , forced expiratory volume in one second (FEV1) , forced expiratory flow 25-75(FEF25-75).Results After the operation , recurrent respiratory tract infections (RRTI) were reported in the children who were operated at the of age 0～12, 13～36 months old(47.1%, 27.3%). The incidence of thorax malformation in these two groups was 41.2% (7 of 17) ,9.1%(1 of 11). 3 of 17 patients(17. 6%) who were operated less than 12 months old demonstrated digestive system symptoms after the operation.In all age groups no statistically significant difference existed in artery blood gas analysis compared with control groups (P>0.05). Chest fluoroscopy showed that the diaphragm was raised postoperatively (2.32 ±0.66, 1.73±0.72, 1.50±0.89 intercostal spaces) and there wasstatistical significant difference among groups (P<0.05) .Pared with the control groups , lung volume and lung compliance decreased and airway resistance increased postoperatively in the children who were operated at less than 36 months old (P<0.05) ; The patients operated over 36 months had normal lung function after operation (P >0.05). Vital capacity max test showed that there was no difference between right-sided phrenic nerve transfers and left-sided phrenic nerve transfers (P>0.05) .Conclusions Transfer of phrenic nerve in children less than 3 years old may cause abnormality of the respiratory system . The younger the patient, the more serious the consequences of the operation. Children older than 3 years tolerated the operation better and it may not lead to respiratory dysfunction in the long term.R651.3...