未成年の虫垂・扁桃摘出術は早期のAMI発症に関連

　粘膜関連リンパ組織（MALT）を除去する虫垂摘出術や扁桃摘出術を受けた場合，長期の健康リスクに影響を与える可能性が指摘されている。スウェーデ ン・カロリンスカ大学病院のImre Janszky氏らは，大規模コホート研究で未成年期に手術を受けた患者を登録し，平均23.5年間追跡。虫垂摘出術で3割強，扁桃摘出術で4割強，早期 の急性心筋梗塞（AMI）が増加していたと報告した

Childhood appendectomy, tonsillectomy, and risk for premature acute myocardial infarction—a nationwide population-based cohort study

Imre Janszky1,2,*,

Kenneth J. Mukamal3,

Christina Dalman1,

Niklas Hammar4,5 and

Staffan Ahnve1

1Department of Public Health Sciences, Karolinska Institutet, Norrbacka, 6th floor, Karolinska University Hospital, Stockholm SE-171 76, Sweden

2Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway

3Division of General Medicine and Primary Care, Beth Israel Deaconess Medical Center, Boston, MA, USA

4Division of Epidemiology, Institute of Environmental Medicine, Karolinska Institute, Stockholm, Sweden

5Epidemiology, AstraZeneca Research and Development, Södertälje, Sweden

*↵Corresponding author. Tel: +46 8 52480116, Fax: +46 8 308008, Email: imre.janszky@ki.se

Received December 6, 2010.

Revision received February 10, 2011.

Accepted March 29, 2011.

Abstract

Aims

Although inflammation contributes to cardiovascular disease, the associations of appendectomy and tonsillectomy, which remove mucosa-associated lymphoid tissue, with risk of acute myocardial infarction (AMI) are unknown. Our aim was to assess the association between these operations performed in childhood and AMI risk later in life.

Methods and results

We conducted a prospective matched cohort study among all Swedish residents born between 1955 and 1970. A national register identified all appendectomies and tonsillectomies. For each patient undergoing appendectomy or tonsillectomy, we randomly selected five controls without the history of the respective operation, matched on sex, age, and county of residence. Participants were followed for fatal and non-fatal AMI for an average of 23.5 years. Because appendiceal and tonsillar tissues have reduced function after adolescence, our primary analyses were restricted to individuals below age 20 at the time of surgery (54 449 appendectomies and 27 284 tonsillectomies). We derived hazard ratios (HRs) from proportional hazard models adjusted for parental occupation and parental history of AMI. Operations before 20 years of age were associated with an increased risk for AMI (417 and 216 events in the appendectomy and tonsillectomy datasets, respectively), with adjusted HRs of 1.33 [95% confidence interval (CI), 1.05–1.70] for appendectomy and 1.44 (95% CI, 1.04–2.01) for tonsillectomy. This association was graded, with the highest risk among those undergoing both procedures, and generally similar among both males and females. Appendectomy and tonsillectomy performed at or above 20 years of age were not associated with the risk of AMI.

Conclusions

We found a higher risk of AMI related to surgical removal of the tonsils and appendix before age 20. These results are consistent with the hypothesis that subtle alterations in immune function following these operations may alter the subsequent cardiovascular risk, but further studies are needed to confirm these findings and to explore possible mechanisms.

小児反復性上気道感染症に対するアデノイド切除、臨床的ベネフィット認めず

文献：van den Aardweg MT et al.Effectiveness of adenoidectomy in children with recurrent upper respiratory tract infections: open randomised controlled trial.BMJ 2011; 343:d5154.

　上気道感染症の反復が見られる1-6歳の小児111人を対象に、アデ ノイド切除の有効性を非盲検無作為化比較試験で検討。追跡期間中央値24カ月の上気道感染症発症率は、介入群7.91人年、経過観察群7.84人年だっ た。介入群は経過観察群と比較して発熱日数が有意に多く、アデノイド切除術の臨床的ベネフィットは認められなかった。

Effectiveness of adenoidectomy in children with recurrent upper respiratory tract infections: open randomised controlled trial

1. M T A van den Aardweg, PhD student and registrar in otorhinolaryngology1,

2. C W B Boonacker, PhD student and clinical epidemiologist2,

3. M M Rovers, associate professor of clinical epidemiology12,

4. A W Hoes, professor of clinical epidemiology and general practice2,

5. A G M Schilder, professor of paediatric otorhinolaryngology; ear, nose, and throat surgeon; and clinical epidemiologist12

Author Affiliations

1. ¹Department of Otorhinolaryngology, University Medical Centre Utrecht, Netherlands

2. ²Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht

1. Correspondence to: A G M Schilder, Department of Otorhinolaryngology, University Medical Centre Utrecht, Wilhelmina Children’s Hospital, HP KE 04.140.5, PO Box 85090, 3590 AB Utrecht, Netherlands A.Schilder@umcutrecht.nl

• Accepted 27 June 2011

Abstract

Objective To assess the effectiveness of adenoidectomy in children with recurrent upper respiratory tract infections.

Design Open randomised controlled trial.

Setting 11 general hospitals and two academic centres.

Participants 111 children aged 1-6 with recurrent upper respiratory tract infections selected for adenoidectomy.

Intervention A strategy of immediate adenoidectomy with or without myringotomy or a strategy of initial watchful waiting.

Main outcome measure Primary outcome measure: number of upper respiratory tract infections per person year calculated from data obtained during the total follow-up (maximum 24 months). Secondary outcome measures: days with upper respiratory tract infection per person year, middle ear complaints with fever in episodes and days, days with fever, prevalence of upper respiratory tract infections, and health related quality of life.

Results During the median follow-up of 24 months, there were 7.91 episodes of upper respiratory tract infections per person year in the adenoidectomy group and 7.84 in the watchful waiting group (difference in incidence rate 0.07, 95% confidence interval −0.70 to 0.85). No relevant differences were found for days of upper respiratory tract infections and middle ear complaints with fever in episodes and days, nor for health related quality of life. The prevalence of upper respiratory tract infections decreased over time in both groups. Children in the adenoidectomy group had significantly more days with fever than the children in the watchful waiting group. Two children had complications related to surgery.

Conclusion In children selected for adenoidectomy for recurrent upper respiratory tract infections, a strategy of immediate surgery confers no clinical benefits over a strategy of initial watchful waiting.