Soehendra教授在第一届华人消化内镜大会上的演讲

Endoscopic Management of Chronic Pancreatitis
Nib Soehendra

Endoscopic management in chronic pancreatitis includes:
1.Pancreatic sphincterotomy
2.Pancreatic stone extraction
3.Stenting of pancreatic main duct
4.Drainage of pseudocyst
5.Treatment of pancreatic abscess
6.Sealing of pancreatic duct fistula
7.Stenting of distal CBD stricture
Chronic pancreatitis is the most common indication for endoscopic intervention in pancreatic diseases.
Chronic pancreatitis is frequently related to acute pancreatitis of different etiologies. The starting point is an attack of acute pancreatitis with autodigestive parenchymal necrosis, which leads to perilobular fibrosis and finally to stricture formation in the main duct. The impaired flow of pancreatic juice increases viscosity and causes plugs of protein in the ducts aggravating the obstruction. This vicious cycle ultimately leads to the development of chronic pancreatitis
With the belief that chronic pancreatitis is an irreversible disease, treatment of the unrelenting pain and deteriorating functions of the gland remain the main goals of all therapeutic modalities. The increase of the intraductal pressure is one of the most important causes of the pain. Pancreatic sphincterotomy, stenting and stone removal in the pancreatic ducts represent therefore the main therapeutic procedures in the endoscopic management of chronic pancreatitis.(fig.1)
Pancreatic sphincterotomy
Endoscopic incision of the pancreatic sphincter is carried out to facilitate ductal stenting and stone extraction. Technically, it is performed in a similar way to biliary sphincterotomy using a double- or triple-lumen sphincterotome over a guide-wire. It is advisable to use a sphincterotome with a monofilament cutting wire of less than 25 mm, and for cannulation a slippery guide-wire (e.g. Terumo guide-wire 0.018 – 0.032”). After selective cannulation of the pancreatic duct, the incision of the sphincter is made stepwise using pure cutting current in the direction of 1-2 o’clock. In case of pancreas divisum, incision of the minor papilla can also be made over a stent using a needle-knife. Biliary sphincterotomy prior to pancreatic sphincter incision is in most of the cases unnecessary. In patients with distal CBD stricture which is frequently present in chronic pancreatitis, biliary sphincterotomy should not be performed, unless biliary stenting is intended.
Ductal stenting
Since stricture of the main pancreatic duct is the most frequently observed pathology in chronic pancreatitis, stenting is the most commonly practiced endoscopic procedure (fig. 2). However, as in any other drainage procedure this treatment is only beneficial if a distinct ductal dilation is present. In our experience, pancreatic duct stenting is successful in around 90% of cases. The common causes of failure are very tight and multiple strictures. Stenting may also be indicated in patients with pancreas divisum suffering from pancreatitis-like pain, as a therapeutic trial to prove that there is inadequate drainage through the minor papilla.

Fig. 2 ERCP findings in chronic pancreatitis (n = 200)
Pancreatic ductal obstruction　　90 %
Intraductal calculi　　　　　　　35%
Cysts　　　　　　　　　　　　　25 %
Pancreas divisum　　　　　　　20 %
Distal CBD obstruction　　　　　35 %

The technique of pancreatic duct stenting is similar to that of biliary stenting and is based on the Seldinger principle. Strictures of the pancreatic main duct however may be more difficult to stent due to their fibrotic, tight and tortuous nature.
Stenting has proved to be safe and effective method of draining the duct in chronic pancreatitis. Complete or partial pain relief can be achieved initially in around 85% of patients. Unfortunately, the figure for pain relief drops to around 60-70% during follow-up, mainly due to stent clogging. As long as the problem of stent occlusion remains, surveillance of patients is mandatory. Stent exchange should be scheduled at 3 months interval. To effectively dilate the stricture, dilating catheter (5 to 11.5 French), dilating balloon (5 to 10 mm according to the diameter of the distal duct) and stent retriever (10 French) are used. Placement of multiple stents for about one year (increase the number of 7-10 French stents every 3 months) has been shown to have encouraging long-term results (fig. 3).
Treatment of pancreatic stones
Pancreatic duct stones are the next most frequent cause of ductal obstruction in patients with chronic pancreatitis. They can be removed following endoscopic sphincterotomy by using a Dormia basket or a balloon catheter if they are mobile and not too large. Unfortunately, most of the obstructing stones are impacted in the duct and located behind a stricture. In these cases, extracorporeal shock wave lithotripsy (ESWL) has first to be applied. After successful disintegration, stone fragments can be extracted endoscopically.
Using the new generation of machine, ESWL is well tolerated by the patients and is not associated with any significant complications. Fragmentation of pancreatic stones can be achieved in 80-100% of cases with pain relief in 50-90% of patients.
Drainage of pseudocysts
Pancreatic pseudocysts which occur with an incidence of around 10-30% in chronic pancreatitis need treatment because they cause symptoms like pain, nausea and vomiting or because they cause complications such as gastric outlet obstruction, jaundice and abscess formation. Pseudocysts occurring in chronic pancreatitis spontaneously resolve less frequently than those found in acute pancreatitis and have a tendency to develop complications especially if treatment if delayed.
Symptomatic pseudocysts, which are usually larger than 6 cm in diameter, can be treated effectively and safely by endoscopic drainage. This can be performed either transpapillary if the cyst communicates with the main pancreatic duct, or by a transmural approach if the cyst has direct contact with the gastric or duodenal wall and produces a recognizable bulge in the lumen.
The size and the proximity of the cyst to the gut wall can be assessed precisely by CT and endoscopic ultrasound (EUS). EUS plays an important role in the endoscopic management of pancreatic pseudocysts. It provides informations concerning interposed vessels and collateral veins which are common in patients with portal hypertension. EUS-guided puncture and drainage is therefore strongly recommended in these patients, and also if there is no endoscopically visible bulging of the stomach or duodenal wall (fig. 4).
Transgastric drainage is the most commonly practiced endoscopic modality. Following EUS-guided puncture of the cyst through the gastric wall using a FNA-needle, a guide-wire is inserted through the needle. Over the guide-wire, a stent or a naso-biliary catheter can be placed. Owing to the relatively high risk of secondary infection due to stent clogging, placement of an additional naso-cystic catheter for continuous rinsing is advisable. Creation of a cyst-gastrostomy using a dilating balloon (10-20 mm diameter) is recommended in infected pseudocysts and pancreatic abscesses. To maintain the opening of cyst-gastrostomy a 10 French double-pigtail stent is placed. Repeated balloon dilatation may be required to remove debris of necrotic tissue from the cyst cavity by using a Dormia basket or Roth retrieval net.
The success rate of endoscopic cyst drainage amounts to 80-90% with a complication rate between 10-15% (bleeding, infection).
Concomitant pancreatic fistulae can be sealed by using the tissue glue n-butyl-2-cyanoacrylate (Histoacryl). Prior to occlusion, sufficient drainage of the cyst and healing of the infection must be ensured. Endoscopic sealing is indicated if leakage persists despite sufficient ductal drainage.

慢性胰腺炎的内镜治疗

　　慢性胰腺炎的内镜治疗包括：
　　1、胰管括约肌切开
　　2、胰管结石取出
　　3、主胰管支架置入
　　4、假性囊肿的引流
　　5、胰腺脓肿的治疗
　　6、胰管瘘的封堵
　　7、胆总管远端狭窄的支架治疗
　　内镜介入治疗胰腺疾病最常见的适应证就是慢性胰腺炎。
　　慢性胰腺炎总是与不同病因所致的急性胰腺炎相关。起初是急性胰腺炎所致的胰实质自身消化坏死，进而导致小叶周围纤维化，最终是主胰管狭窄形成。胰液流出障碍引起粘稠度增加，并形成蛋白质栓子，又进一步加重胰管阻塞。这种恶性循环最终促成了慢性胰腺炎。
　　由于慢性胰腺炎是一种不可逆的疾病，处理持续的疼痛及改善进行性减退的胰腺分泌功能就成为所有治疗的首要目标。胰管内压增高是引起疼痛的一个主要原因，因此，胰管括约肌切开、置入支架及胰管结石取出就成为内镜治疗慢性胰腺炎的主要操作内容。
胰管括约肌切开术
内镜下行胰管括约肌切开，主要是为了便于置入支架及取石。其操作技术类似于胆管括约肌切开。在导丝引导下使用双腔或三腔切开刀进行切开。建议使用超滑导丝（如Terumo　0.018-0.032”导丝）。选择性胰管插管后沿1-2点钟方向用单纯切割电流切开。对胰腺分裂症患者，行副乳头切开可先置入导管再沿导管用针状刀切开。对大多数病例不必预先做胆管括约肌切开。对慢性胰腺炎常并发的远端胆总管狭窄也不需要进行胆道括约肌切开，除非需要置入胆道支架。

胰管支架置入术

　　由于慢性胰腺炎最常见的病理变化是主胰管狭窄（表1）置入支架主成为内镜治疗最常用的方法。然而就如同所有其他引流治疗一样，该方法只有在存在近端胰管扩张的情况下才是有益的。我们的经验：胰管支架置入的成功率在90%左右，失败的常见原因是严重的狭窄及多发狭窄。胰管支架的另一个适应证是导致胰腺炎样疼痛的胰腺分裂症，其作为一种治疗方法证明了存在副乳头的引流不足。

表1　胰腺炎的ERCP表现
胰管梗阻 　　　　　　90%
胰管结石　　　　　　35%
囊肿　　　　　　　　25%
胰腺分裂　　　　　　20%
胆总管远端狭窄　　　35%

　　在慢性胰腺炎，支架置入已被证实是一种安全有效引流胰管的方法。在85%左右的病人可完全或部分缓解疼痛。不幸的是，在随访期，疼痛缓解率下降到60－70%，原因主要是支架阻塞。只要支架阻塞的问题仍存在，就必须对患者进行随访监测。一般间隔3个月需要更换支架。为了有效扩张狭窄，需要使用扩张导管（5-11.5Fr）、扩张球囊（按近端导管直径选择5-10mm）及支架回收器（10 Fr）。在一年内使用多支架置入（每3个月从7-10 Fr逐步增加支架）获得长期疗效的结果令人鼓舞。

胰管结石的治疗

　　慢性胰腺炎患者胰管阻塞的另一个常见原因是胰管结石。如果它们可移动而且不是很大，则可通过内镜下胰管括约肌切开后用Dormia网篮或取石球囊取出。但通常情况下它们总是位于狭窄段后方并紧紧卡在胰管内。在这种情况下，可先使用体外震波碎石（ESWL），当结石破碎后，再通过内镜取出其碎片。
　　在使用新一代仪器后，患者可很好地耐受ESWL，而且没有显著的并发症。80－100%的患者胰管结石可被粉碎，其中50－90%的患者疼痛可缓解。

假性囊肿的引流

　　约10－30%的慢性胰腺炎患者会发生假性囊肿。假性囊肿需要治疗，因为它们可引起诸如疼痛、恶心呕吐等症状，而且还可导致胃排空障碍，黄疸、脓肿形成等并发症。慢性胰腺炎所致假性囊肿较少像急性胰腺炎形成假性囊肿那样容易吸收，而且治疗不及时易出现并发症。

　　有症状的假性囊肿通常直径大于6cm，可以通过内镜下引流术对其进行安全有效的治疗。如果囊肿与主胰管相通就可经乳头引流；如果囊肿紧贴胃或十二指肠壁并在腔内形成一个显著的凸起，则可经胃十二指肠壁进行引流。

　　囊肿大小及其与胃肠壁的距离可通过CT或内镜超声检查（EUS）精确测量。内镜超声在内镜下治疗胰腺假性囊肿中发挥重要作用。在门脉高压症患者，EUS可提供关于囊肿与肠壁间血管及伴行静脉的信息，因此在这类患者以及胃十二指肠壁上无明显内镜下可见的凸起时，强烈推荐使用EUS引导下的穿刺及引流。

　　经胃壁引流是最常用的内镜治疗方法，在内镜超声引导下，使用细针经胃壁穿刺囊肿成功后，通过细针置入导丝，再沿导丝置入支架或鼻胆管。由于支架堵塞后囊肿继发感染的危险性较高，建议再放置鼻－囊肿导管进行持续冲洗。

　　在假性囊肿感染或胰腺脓肿形成时推荐使用扩张球囊（10-20mm直径）行囊肿－胃造瘘术。为保持造瘘口通畅，需放置10Fr的双猪尾引流支架。可使用Dormia网篮或Roth回收网取出囊肿内的坏死组织碎屑，为此还需要反复气囊扩张。

　　内镜下囊肿引流术的成功约80－90%，并发症发生率在10－15%（包括出血、感染等）。

　　伴随的胰瘘可使用组织胶N－丁基－2－氰丙烯酸（Histoacryl）进行封堵，在封堵前，必须首先进行充分的胰管引流及控制感染。如果给予充分的胰管引流仍有持续的胰液漏出则是内镜下封堵的适应证。

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