Presentation of Case
This 29-year-old man was admitted because of fevers, cough and chest pain for 2 weeks.
He had been otherwise healthy before. He started to have fevers, chills, cough and chest pain 2 weeks earlier before this evaluation. Fevers up to 40 ℃ and chills developed intermittently, which responded to medications that were given at outside clinics. The cough was productive of purulent sputum, which worsened at night time. The chest pain was located at the right upper chest, dull in character and worsened with coughing. He also took some Chinese herbs without benefit. A diagnosis of pneumonia was made at an outside clinic. He was then admitted for further evaluation and treatment.
On physical examination, this patient was clear in consciousness. The temperature was 37.6 ℃, the pulse 100 beats per minute, the respiratory rate 28 breaths per minutes and blood pressure 108/62 mmHg. His conjunctivae were pink and sclerae were anicteric. His neck was supple without lymphadenopathy. Chest examination showed mild decrease of breath sounds at the right upper chest. No spider angioma or caput medusa was noted. Heart examination disclosed regular heart beats without murmurs. His abdomen was soft and flat and no tenderness or rebound tenderness. The liver and spleen were impalpable. Bowel sounds were normal and there was no edema in the extremities.
<Laboratory data>
1.Hemogram
WBC |
RBC |
Hb |
HT |
MCV |
PLT |
K/uL |
M/uL |
g/dL |
% |
fL |
K/uL |
15.28 |
3.2 |
11.1 |
33.5 |
104.7 |
488 |
Meta |
Band |
Seg |
Eos |
Baso |
Mono |
0 % |
2.0 % |
73.0 % |
1.0 % |
0.3% |
10.0 % |
Lym |
|
|
|
|
|
14.0 % |
|
|
|
|
|
2.Biochemistry
Alb |
Glo |
T-Bil |
D-Bil |
AST |
g/dL |
g/dL |
mg/dl |
mg/dl |
U/L |
3.2 |
2.4 |
0.46 |
0.24 |
57 |
ALP |
r-GT |
BUN |
CRE |
ALT |
u/L |
u/L |
mg/dl |
mg/dl |
U/L |
423 |
223 |
7.6 |
0.9 |
45 |
GLU |
Na |
K |
CRP |
|
mg/dl |
mmol/L |
mmol/L |
mg/dl |
|
96 |
132 |
4.3 |
27.11 |
|
Chest x-ray: a cavitary lesion at the right upper lung with air-fluid level (Fig. 1)
<Course and Treatment>
After admission, piperacillin/tazobactum and azithromycin were given. Computed tomography of the chest revealed a 6.2-cm cavitary lesion with adjacent consolidation at the right upper lung (Fig. 2), suggesting a lung abscess. Thoracentesis showed exudative pleural effusion. The total WBC count of the aspirate was 35000/mcL(L:N: (M+H)=2:90:8), and the glucose level 68 mg/dL. The culture of a pleural effusion specimen was no growth. A sputum culture revealed normal flora of the oral cavity, including viridans streptococci and Neisseria species. Tests for Legionella and chlamydia antigen were both negative. Abnormal liver function was noted, but the results of abdominal sonography and viral markers were unremarkable. His airway symptoms and fever resolved gradually and follow-up chest radiograph showed decreased right upper lung opacity.
He had had episodes of acid regurgitation, dysphagia, and frequent vomiting since childhood, but he did not pay much attention to these symptoms. Because of swallowing disturbance, he was forced to drink lots of water or soup. Upper gastrointestinal endoscopy was performed to reveal multiple gastric ulcers and duodenal ulcers. The esophagus was unremarkable. Biopsy of the gastric ulcer showed chronic gastritis without Helicobacter pylori infection. Barium esophagogram showed remarkably dilated esophagus with fluid retention and bird’s beak appearance at the esophago-gastric junction (Fig. 3). A diagnosis of achalasia was made. Endoscopic ultrasound with esophagus biopsy was performed, which didi not reveal malignant infiltration at the esophago-gastric junction. Esophageal manometry showed aperistalsis, elevated resting pressure and poor relaxation of the lower esophageal sphincter (Fig 4), which were characteristics of achalasia. Endoscopic pneumatic dilatation was performed smoothly and his symptoms, including dysphagia and vomiting, were significantly relieved. He was then discharged and followed as an outpatient.
<Discussion and Analysis>
本病例是食道失弛症 (achalasia)以肺膿瘍為臨床表現的少見案例，此案例提醒我們，由於患者是年輕人，健康狀況大致良好，並非好發膿瘍之高危險群，因此，在治療肺膿瘍之餘，仍要從病態生理學之角度，透過詳細之病史詢問，找到根本病因加以解決。
食道失弛症，亦稱為食道弛緩不能，主要是正常食道蠕動的功能及下食道括約肌的舒張受到不知何種原因的影響，因而難以將食物順利送到胃內。食道失弛症之發生率低，一般來說，年紀愈大，比例愈高，不過20-30歲之間的患者也不少見，呈現一雙峰之分布。根據國外調查，盛行率大約每十萬人中有十人，發生率則每十萬人僅有一人，男女性別發生之比例類似。
臨床表現
食道失弛症的病程是漸進式的緩慢進展。剛開始患者可能會覺得喉嚨異物感，慢慢感覺吞不下固體食物，因此有些患者會盡量改吃流質食物，或是藉著進食時多喝水、多喝湯等方法讓食物順利進入胃部。因為一開始有吞嚥上的困難，不少患者常被誤以為是其他疾病，例如腸胃道長腫瘤，求醫檢查卻往往正常。此外，患者有時會感覺胸痛、食物逆流等不適，而誤以為是胃食道逆流，卻是藥物治療無效。尤有甚者，可能因為吃飽後立刻平躺睡覺，積在食道的食物因而逆流進入氣管，引發吸入性肺炎或肺膿瘍，此病例即為一典型例子。
成因
食道失弛症的病因至今還不清楚，目前認為與遺傳、免疫或感染有較密切關係。由於食道的蠕動是由腸胃道的自律神經控制，如果控制肌肉的神經元曾因為局部發炎、或是病毒感染受到傷害，就可能造成下食道括約肌的舒張困難，吞下的食物不易通過而堆積在食道，時到嚴重擴張而失去蠕動功能。另外，也有可能是自體免疫發生問題，神經元受到攻擊而導致肌肉失去收縮或放鬆功能所致。
診斷方式
傳統內視鏡檢查下，胃鏡通常仍然能順利通過下食道括約肌，除非食道已相當擴大或有食物經禁食6-8小時後仍殘留於食道，通常不易被診斷出來，如本例在第一次的內視鏡檢查即未發現任何食道異常。食道鋇劑攝影，可以發現食道上端明顯變寬，食道與胃交接處狹窄，看起來像是個「鳥嘴」的形狀 (bird's beak)，這時即可高度懷疑是食道失弛症。要確診是否為食道失弛症，最重要的檢查還是食道壓力檢測 (esophageal manometry)。這項檢查會一方面檢查食道的蠕動功能，另一方面則是測試食道下方括約肌於休息時及吞嚥時放鬆的壓力大小，最典型的食道壓力檢測表現即為食道同時收縮 (simultaneous contraction)，即所謂之aperistalsis。此外，少數患者因為罹患賁門癌等腫瘤壓迫，也會造成假性的食道失弛症狀，因此懷疑是食道失弛症，往往要配合食道功能檢測、上消化道攝影、胃鏡甚至內視鏡超音波檢查，才能正確做出診斷。
治療方式
食道失弛症的治療一般會先採取內科的保守療法，包括鈣離子阻斷劑、硝酸鹽類藥物，目的讓食道下括約肌放鬆，但通常藥物治療的效果不佳，這時往往需要採取內視鏡治療或外科手術。內視鏡治療，即所謂的「氣球擴張術」，在內視鏡直接觀察及外部X光導引下，利用撐大的氣球，撐開下括約肌，以達到放鬆的效果。治療的成功率約七、八成左右。因為不用開刀，外表無傷口，身體恢復快，住院期間短，術後隔日患者即能順利進食。不過氣球擴張術治療的缺點，在於約有三成的患者在一年後會復發，特別是年輕人可能因為肌肉較紮實，更容易復發。因此，超過50歲的患者，採用此法的治療效果較佳。氣球擴張術可能的併發症包括出血及食道破裂，發生的機會不高，約2-6%，大部分患者只須保守治療，包括禁食及藥物治療。極少數併發症則需要外科手術處理。
另一種治療選項則是外科手術治療，包括傳統或內視鏡手術的方式，把下括約肌的肌肉直接切開，達到放鬆效果，治療效果顯著，10年的成功率約八成至八成五左右，較氣球擴張術持久。手術治療出現併發症的機率不高，約6%。此外，因為開刀把肌肉放鬆，高達五成患者術後會發生胃食道逆流，需要長期服用制酸劑。
由於外科手術治療與氣球擴張術之治療效果都很好，臨床上醫師會根據患者的年紀、身體狀況及病人個人意願等因素，與患者詳細解釋與討論，最後再選擇最適合的治療方式。無論何種方式，生活品質相較治療前都能大大的提升。
<References>
- Kessing et al. Clin Gastroenterol Hepatol 2011 May 9
- Chuah et al. J Gastrointest Surg 2009;13:862-7
- Boeckxstaens et al. N Engl J Med. 2011;364:1807-16.
- Tanaka et al. J Gastroenterol 2010; 45:153–158
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Case Discussion
繼續教育考題