Behrns K E, Sarr M G
Mayo Postgraduate School of Medicine, Rochester, Minnesota.
Adv Surg. 1994;27:233-55.
In summary, although gastric emptying disorders are relatively uncommon, they are potentially devastating conditions resulting from pathophysiologic motor disturbances. Rapid gastric emptying of liquids is the hallmark of the dumping syndrome and occurs after operations, including vagotomy. Vagal denervation abolishes receptive relaxation and accommodation in the proximal stomach (the storage site for ingested liquids) resulting in increased intragastric pressure which forces liquids through an ablated or bypassed pylorus. Dumping symptoms may occur in up to 50% of postgastrectomy patients, but most patients are treated satisfactorily by dietary manipulation or, in the rare incapacitated patient, by the long-acting somatostatin analogue octreotide. Reconstructive gastric surgery may rarely be indicated to slow gastric emptying and alleviate the dumping syndrome. Reoperative procedures include pyloric reconstruction after pyloroplasty, small intestinal pouches, interposed isoperistaltic and antiperistaltic jejunal segments, and a Roux-en-Y gastrojejunostomy. Interposed jejunal loops and the Roux-en-Y gastrojejunostomy provide the most satisfactory results. Delayed gastric emptying may occur in the acute postoperative period or be a late complication of gastric surgery. Loss of vagal input to the gastric antrum and resection of the antrum with vagotomy may produce an atonic stomach or atonic gastric remnant, respectively, which fails to grind and propel solids into the small intestine. Scintigraphic imaging of both the liquid and solid components of the meal is a valuable diagnostic adjunct. Gastric ileus occurring in the early postoperative period generally resolves within 6 weeks of operation, and the temptation to reoperate on a nonobstructed stomach should be avoided. Pharmacologic therapy of chronic gastric stasis with the benzamide prokinetic agents (metoclopramide, cisapride, renzapride), domperidone, and the motilin agonist erythromycin, may be effective initially, but long-term results are still undefined, and postvagotomy and postgastrectomy patients have not been studied adequately. Persistent postoperative gastric atony and the Roux stasis syndrome should be managed surgically by near-total gastrectomy which should result in symptomatic improvement in two thirds of patients.
总之,尽管胃排空障碍相对不常见,但它们是由病理生理运动紊乱导致的潜在毁灭性疾病。液体胃排空过快是倾倒综合征的标志,见于包括迷走神经切断术在内的手术后。迷走神经切断术消除了胃近端(摄入液体的储存部位)的容受性舒张和适应性舒张,导致胃内压升高,迫使液体通过被切除或绕过的幽门。高达50%的胃切除术后患者可能出现倾倒症状,但大多数患者通过饮食调整可得到满意治疗,极少数丧失能力的患者则使用长效生长抑素类似物奥曲肽治疗。很少需要进行重建性胃部手术来减缓胃排空并缓解倾倒综合征。再次手术包括幽门成形术后的幽门重建、小肠袋、插入顺蠕动和逆蠕动空肠段以及Roux-en-Y胃空肠吻合术。插入空肠袢和Roux-en-Y胃空肠吻合术效果最令人满意。胃排空延迟可能发生在术后急性期或作为胃部手术的晚期并发症。胃窦部迷走神经输入丧失以及迷走神经切断术切除胃窦部可能分别导致无张力胃或无张力胃残端,无法研磨并将固体推进小肠。对餐食的液体和固体成分进行闪烁扫描成像有助于诊断。术后早期出现的胃麻痹一般在术后6周内缓解,应避免对无梗阻的胃部进行再次手术。使用苯甲酰胺促动力剂(甲氧氯普胺、西沙必利、瑞巴派特)、多潘立酮和胃动素激动剂红霉素对慢性胃潴留进行药物治疗,最初可能有效,但长期效果仍不明确,且尚未对迷走神经切断术后和胃切除术后患者进行充分研究。持续性术后胃无张力和Roux淤滞综合征应通过近乎全胃切除术进行手术治疗,三分之二的患者症状应会改善。