Exocrine pancreatic function in correlation to ductal and parenchymal morphology in chronic pancreatitis

A prospective investigation of the diagnostic value of imaging procedures, computed tomography (CT) and endoscopic retrograde pancreatography (ERP) in comparison with the exocrine pancreatic function test, was done in 109 patients with chronic pancreatitis. The sensitivity of the secretin-ceruletide test (SC) proved to be 87% as compared with 89% for ERP and 78% for CT. The severity of morphological lesions noted in ERP and CT, shows a significant correlation to the degree of the exocrine functional impairment (p less than 0.001). 75% of patients with chronic pancreatitis had corresponding functional and ductal changes in advanced-stage disease, while only 47% of the patients with severe pancreatic insufficiency had CT changes of a corresponding degree. ERP lesions such as ductal obstruction and marked duct dilatation, and CT alterations such as atrophy and ductal dilatation, are almost always coupled with severe pancreatic insufficiency in chronic pancreatitis. Calcific lesions demonstrated by CT are also found in less advanced stages of exocrine insufficiency. Discrepancies between functional and morphological alterations were remarkable in "early" stages of the disease.     

Evolution of lesions of the pancreatic duct following acute pancreatitis associated with a pseudocyst

AIMS: After an episode of acute pancreatitis, there is usually no sequelae; nevertheless cases of ductal stenosis have been reported. The aim of our study was to evaluate the frequency of pancreatic duct lesions after acute pancreatitis complicated by pseudocyst. PATIENTS AND METHODS: Between 1983 and 2004, 67 patients were admitted for severe acute pancreatitis. Out of these 67 patients, 36 patients were excluded because of chronic pancreatitis (N=12), intraductal papillary mucinous tumors of the pancreas (N=3), carcinoma (N=2), cystadenoma (N=3), alcohol consumption > 40 g/d (N=6), post-traumatic acute pancreatitis (N=3), and a follow-up less than 12 months (N=7). RESULTS: A stenosis of the main pancreatic duct was observed in 52% (16/31) of patients. This stenosis was isolated in 100% of cases, complete for 69% of them (11/16) and associated with upstream dilatation in 69% of cases (11/16). Although the pseudocyst was located in the body of the pancreas in 7/31 cases (48%), the stenosis was located in the head in 9/16 cases (56%). The predictive criteria of pancreatic duct lesions were complications associated with pseudocyst: extra-luminal compression (P=0.01), and vascular thrombosis (P=0.02). CONCLUSION: After an episode of acute pancreatitis complicated by pseudocyst, pancreatic duct stenosis is observed in 52% of the cases. These results show that complete resolution of pancreatic abnormalities after acute pancreatitis is not achieved systematically.     

Incidence of the focal type of autoimmune pancreatitis in chronic pancreatitis suspected to be pancreatic carcinoma: experience of a single tertiary cancer center

Objective. With an increase in autoimmune pancreatitis (AIP) being reported, the focal type of AIP, which shows localized narrowing of the main pancreatic duct and focal swelling of the pancreas, has recently been recognized. Therefore, cases of focal-type AIP subjected to surgical intervention for presumptive malignancy might previously have been diagnosed as mass-forming chronic pancreatitis. The aim of this study was to elucidate the incidence of focal-type AIP in resected chronic pancreatitis at a single tertiary cancer center. The clinical and radiological features of focal-type AIP were also evaluated. Material and methods. We re-evaluated 15 patients who underwent pancreatic resection with a presumed diagnosis of pancreatic ductal adenocarcinoma, and who in the past had been diagnosed pathologically as having chronic pancreatitis. Results. Seven of 15 patients showed AIP, and the other 8 patients were diagnosed as having mass-forming chronic pancreatitis not otherwise specified by pathological retrospective examination. In other words, nearly half of the cases of resected chronic pancreatitis that were suspected to be pancreatic carcinoma preoperatively showed focal-type AIP. Regarding the characteristic findings of focal-type AIP, narrowing of the pancreatic duct on endoscopic retrograde pancreatography (ERP) might be diagnostic. Conclusions. Focal-type AIP is not a rare clinical entity and might be buried in previously resected pancreatic specimens that in the past were diagnosed simply as mass-forming pancreatitis.     

Papillary adenoma of the pancreas with excessive mucin secretion.

A 68-year-old woman with papillary adenoma of the pancreas with excessive mucin secretion is reported. The patient was initially diagnosed as having chronic pancreatitis because of a history of repeated attacks of pancreatitis and localized dilatation of the main pancreatic duct. Four years later, endoscopic retrograde pancreatography showed markedly diffuse dilatation of the entire main pancreatic duct with amorphous filling defects of mucin. Excretion of mucin was observed through the enlarged orifice of Vater's ampulla. The patient was treated with distal pancreatectomy, and papillary adenoma with abundant mucin in the cytoplasm was histologically demonstrated. We describe unique clinical features of "mucin-producing pancreatic tumor" and discuss an important role of endoscopic retrograde pancreatography in the diagnosis.     

Serum Elastase 1 Appears Specific for Cancer of the Pancreatic Head

Molecular size distribution of serum elastase 1 was investigated, by means of Sephadex G-200 gel filtration, in 10 patients with acute pancreatitis and in 19 patients with pancreatic cancer associated with high values of serum elastase 1. The elution profile of immunoreactive elastase 1 (IRE1) showed a single peak in the molecular position of the alpha 1-antitrypsin-elastase 1 (alpha 1-AT-E1) complex in all 10 patients with acute pancreatitis, six of seven patients with cancer of the pancreatic body-tail, and in the two patients with cancer of the pancreatic uncinate without poststenotic dilatation of the main pancreatic duct. The elution profile of all patients with pancreatic head cancer and one of seven patients with pancreatic body-tail cancer with a poststenotic dilatation of the main pancreatic duct showed two peaks: the first was eluted in the position of the alpha 1-AT-E1 complex, and the second was eluted between alpha 1-AT-E1 and elastase 1. The molecular weight of the IRE1 appearing specifically in patients with cancer of the pancreatic head was about 46,000 to 48,000, which was different from the 30,500 molecular weight of (pro)elastase 1. It is possible that proelastase 1 binding with an unknown substance exists in patients with pancreatic cancer. These data suggest that the stenosis or obstruction of the pancreatic duct by cancer probably liberates proelastase 1 from the normal pancreatic acinal cells into the blood. Therefore, the determination of the molecular size distribution of elastase 1 in the serum appears useful in the differential diagnosis of acute pancreatitis and pancreatic head cancer accompanied by pancreatitis.     

Pancreatic morphology and function in relationship to pain in chronic pancreatitis

The correlation of pancreatic pain and the degree of morphological and functional changes was prospectively investigated in 64 patients (45 males, 19 females) with chronic pancreatitis. All patients underwent clinical examination and diagnostic investigations by means of endoscopic retrograde pancreatography (ERP), computed tomography (CT) and exocrine pancreatic function test (secretin-ceruletide; SC). The individual tests were performed within 4 weeks in all patients. No significant correlation was found between the degree of pain and the severity of ERP and CT findings. Severe pain was found in 62% of patients with advanced ductal changes, and in 41% of patients with advanced parenchymal lesions. 58% of patients with severe pain had marked exocrine insufficiency. Ductal changes characterized by obstruction of the main pancreatic duct were most frequently associated with severe pain (58%). Less often, severe pain was associated with duct dilatation (34%) or with slight duct changes (26%). Among parenchymal lesions as revealed in CT, large cysts were most frequently related to severe pain (62%). A notable finding was that 89% of patients presenting with calcifications in CT still experienced pain and 39% of them had severe pain. The combined diagnostic approach is useful for the individual therapeutic management, but does not provide insight into the mechanisms of pain in chronic pancreatitis.     

Minute pancreatic carcinoma with initial symptom of acute pancreatitis

We experienced a case of minute pancreatic carcinoma in a 59‐year‐old man who complained of upper abdominal pain after drinking alcohol. Abdominal ultrasonography (US) revealed dilatation of the main pancreatic duct (MPD). Abdominal computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) showed slight dilatation of the MPD and its obstruction near the portal vein. Endoscopic retrograde cholangiopancreatography (ERCP) demonstrated occlusion of the MPD, and cytology of aspirated pancreatic juice was negative for malignancy. With the diagnosis of benign localized obstruction of the MPD, the patient underwent surgery. There was a clear demarcation of hardness and color of the pancreas on the left margin of the superior mesenteric vein, and the caudal pancreas was hard and fibrotic. Intraoperative US revealed slight dilatation of the MPD, and the aspiration cytology result was class IV. First, segmental resection of the pancreas was performed, but pathological examination of frozen section showed neither malignancy nor stenotic lesion. An additional small portion of the proximal pancreas was resected. The specimen included a ductal carcinoma, 5mm in diameter. Accordingly, a pylorus‐preserving pancreatoduodenectomy was performed. Microscopically, the minute carcinoma had already penetrated the duct wall and infiltrated lymph vessels and veins. The patient has been under close observation at our outpatient clinic, and so far there have been no signs of recurrence. To improve the poor prognosis of pancreatic cancer, we should be alert to the occurrence of acute pancreatitis as an initial symptom.     

The double duct sign in patients with malignant and benign pancreatic lesions

BACKGROUND: The double duct sign, a simultaneous stenosis of the common bile duct and the pancreatic duct by endoscopic retrograde cholangiopancreatography (ERCP), has been reported to predict the presence of pancreatic cancer with a high degree of certainty. METHODS: To test the specificity of the double duct sign for pancreatic cancer in patients with malignant and benign pancreatic lesions, we have reviewed all ERCP films obtained during a 24-month period (n = 1209) and corresponding clinical follow-up data obtained during a period of 4 years. RESULTS: Forty-three patients were identified as having a double duct stenosis on ERCP, 15% of whom did not have pancreatic carcinoma. In 4 patients chronic pancreatitis was confirmed by serial histologic sections of the surgical specimen. Data on the lengths of the stenotic segment in either the pancreatic duct or the bile duct did not contribute to a better discrimination between benign and malignant disease. CONCLUSION: The specificity of the double duct sign in predicting the presence of pancreatic cancer appears to be lower than previously reported. Better discrimination between malignant and benign disease of the pancreas will be difficult to achieve with existing imaging techniques.     

Pancreatic ductal morphological pattern and dilatation in postoperative abdominal pain in patients with congenital choledochal cyst: an analysis of postoperative pancreatograms

BACKGROUND: Postoperative abdominal pain associated with pancreatitis has been reported as a pancreas-associated complication after total biliary excision. The aim of the present study was to determine pancreatic ductal patterns in the head of the pancreas and evaluate pancreatic ductal dilatation in patients presenting with postoperative abdominal pain after radical biliary excision for congenital choledochal cyst. METHODS: Postoperative endoscopic retrograde pancreatography (ERP) was performed in a total of 38 patients (27 female and 11 male) with a history of postoperative abdominal pain or an increase in serum and urinary amylase on laboratory analysis. Pancreatic ductal configuration and ductal dilatation were determined. RESULTS: Pancreatic configurations included the usual type (n = 20), ansa pancreatica type (n = 11), loop type (n = 5), and divisum type (n = 2). Dilatation of the pancreatic duct was observed in 34 patients. The common channel was dilated in 29 patients. Mild postoperative pancreatitis occurred in 4 patients in the long term. Protein plugs were observed in the dilated pancreatic duct. CONCLUSIONS: Pancreatic ductal morphological pattern and ductal dilatation, possibly caused by long-standing stagnation of the pancreatic juice, may be associated with postoperative abdominal pain and pancreatitis in congenital choledochal cyst.     

Frequency and severity of post-ERCP pancreatitis correlated with extent of pancreatic ductal opacification

BACKGROUND: Pancreatitis is the most common complication of diagnostic and therapeutic ERCP. Almost certainly, the etiology of this pancreatitis is multifactorial. OBJECTIVE: The primary objective of this study was to evaluate the relationship between the extent of pancreatic ductal opacification and the frequency of pancreatitis. DESIGN: Retrospective study. SETTING: The ERCP database at our institution was searched for prospectively collected data from 1994 to 2005. PATIENTS AND INTERVENTIONS: A total of 14,331 ERCPs were included in the analysis. Patients were divided into 4 groups according to the extent of pancreatic duct opacification: group 1, no attempted opacification or failed cannulation of the pancreatic duct (n = 6739); group 2, opacification of head only (n = 845); group 3, opacification of head and body (n = 2061); and group 4, opacification to the tail (n = 4685). The incidence and severity of pancreatitis was compared between and within each group. RESULTS: The overall pancreatitis rate was 4.0%. There was a progressively higher frequency of pancreatitis with increased extent of opacification to the pancreatic ductal system (P < .001). The overall pancreatitis severity was mild in 2.9%, moderate in 0.8%, and severe in 0.3% of cases. There was a significant difference in pancreatitis severity between patients with pancreatogram (regardless of grade of filling) and patients without pancreatogram. (P < .001). However, there was no difference in the pancreatitis severity between groups 2 to 4 (patients with pancreatogram). Age (65 years vs >65 years), sex, and type of procedure performed (diagnostic and therapeutic) were not significantly different beyond the extent of pancreatic ductal opacification. Multivariate analysis showed that suspected sphincter of Oddi dysfunction with manometry and the extent of pancreatic duct opacification were independent predictors of post-ERCP pancreatitis. CONCLUSIONS: Less filling of the pancreatic ductal system was associated with less post-ERCP pancreatitis. Before performing endoscopic retrograde pancreatography, endoscopists should carefully evaluate whether any pancreatogram or what extent of pancreatogram is needed clinically. Greater use of noninvasive pancreatography and less use of endoscopic retrograde pancreatography should decrease post-ERCP pancreatitis.     

Hemosuccus pancreaticus (bleeding into the pancreatic duct). A rare complication of pancreatitis

HISTORY AND ADMISSION FINDINGS: A 41-year-old man was admitted because of recurrent tarry stools and dizziness. Chronic pancreatitis induced by alcoholism was known. The main abnormal laboratory finding was anaemia (haemoglobin 4.6 g/dl, erythrocytes 2.28/fl). INVESTIGATIONS, TREATMENT AND COURSE: At endoscopy of the oesophagus, stomach and duodenum, fresh blood was found in the duodenum, a small trickle of blood coming from the papilla of Vater. Endoscopic retrograde cholangiography discovered no abnormality in the biliary system. Selective contrast imaging of the pancreatic duct demonstrated a short prepapillary stenosis and a prestenotic dilatation (up to 15 mm diameter) of the pancreatic duct with a cloudy contrast filling defect. After catheter withdrawal from the pancreatic duct blood spurted from the papilla. Emergency angiography revealed pseudoaneurysmatic dilatation of the gastroduodenal artery in the region of the head of the pancreas. At selective catheterization this artery was successfully occluded with metal coils placed both proximally and distally to the source of bleeding. CONCLUSION: Gastrointestinal bleeding is a rare but potentially life-threatening complication of pancreatitis. When searching for bleeding in the upper gastrointestinal tract, the papilla of Vater should be looked for as a possible source. Bleeding from the pancreas occurs particularly in pancreatitis, pancreatic pseudocyst or pancreatic tumour.     

Proximal migration of transanastomotic pancreatic stent following pancreaticoduodenectomy and pancreaticojejunostomy.

BACKGROUND: The use of catheters to stent the pancreaticojejunal anastomosis following pancreaticoduodenectomy is practiced by some surgeons. Their long-term effects in this setting, however, remain unknown. METHODS: A 60-yr-old woman underwent a potentially curative pylorus preserving pancreaticoduodenectomy for Stage I ampullary carcinoma. Roux-en-Y pancreaticojejunostomy was constructed over a short stent. She presented 4 yr later with abdominal pain, steatorrhea, and weight loss. Computed tomography revealed a stent within the proximal pancreatic duct, with gross upstream ductal dilatation and parenchymal features of chronic pancreatitis. RESULTS: Laparotomy revealed no disease recurrence. The stent, removed through a jejunotomy, was occluded. On-table pancreatogram demonstrated a 3-cm proximal duct stricture. Drainage was achieved with a lateral pancreaticojejunostomy (modified Puestow procedure). Recovery was uneventful, with clinical recovery of pancreatic exocrine function at 6 mo follow-up. CONCLUSION: Proximal migration of transanastomotic pancreatic stent with subsequent development of chronic pancreatitis is a potential complication following pancreaticoduodenectomy. It can be managed effectively with stent removal and a lateral pancreaticojejunostomy.     

Chronic pancreatitis at early age of onset presenting interesting findings through endoscopic retrograde pancreatography and chemical analysis of nonopaque pancreatic concretion

Summary This case concerns a 20-year-old male patient with an approximate 10-year history of recurrent and severe abdominal pain radiating to the back. Endoscopic retrograde cholangiopancreatography revealed a short obstructing stenosis of the main pancreatic duct in the head of the pancreas, marked and tortuous dilatation of the prestenotic portion of the main pancreatic duct and its side branches, and a filling defect in the side branch in the body of the gland. Pancreaticojejunostomy was performed to induce decompression of the pancreatic duct. Histology of the pancreas showed advanced chronic pancreatitis. Three nonopaque concretions were obtained at operation. The largest one, which was milky white in appearance and elastic and soft in consistency, proved to be made up of protein. The concretion was rich in acidic amino acids, but poor in basic or aromatic residues. The molar composition of amino acids in the concretion was, in decreasing order, aspartic acid, serine, valine, glycine, and glutamic acid. Powder x-ray diffractometry revealed no crystalline structures.     

Ultrasound secretin test in patients with pancreas divisum--an aid in the diagnosis of papillary or dorsal duct stenosis?

BACKGROUND: Pancreas divisum is a common anatomical variant of pancreatic ductal anatomy. Obstruction of the accessory papilla could cause pain and pancreatitis. It has been suggested that accessory papillary sphincter obstruction can be assessed by sonographic measurement of pancreatic duct diameter after secretin stimulation. METHODS: We now compared our results of sonographic pancreatic duct diameter measurements before and during 10 min after intravenous injection of 1 CU secretin per kg body weight in 32 patients with confirmed pancreas divisum and 20 healthy volunteers. RESULTS: The healthy controls showed a short-lasting duct caliber enlargement by about 93% of the basal diameter within 5 min after secretin injection. 25 pancreas divisum patients without pancreatic disease had a secretin-induced duct dilatation by about only 58%. In four patients with pancreas divisum and chronic pancreatitis no or just a slight duct dilatation was observed after stimulation. Two patients with dorsal duct stenosis as well as one patient with accessory papilla stenosis, however, showed a marked and prolonged secretin-induced duct enlargement by about 155% of the basal duct diameter. CONCLUSION: In this investigation pancreatic duct response to secretin stimulation in pancreas divisum patients without pancreatic disease was less marked than in normal individuals. Thus, a particularly distinct and long-lasting duct dilatation could support the suspicion of accessory papilla or pancreatic duct stenosis.     

A case of pancreatic carcinoma with suspected autoimmune pancreatitis

We present a case of pancreatic carcinoma with strongly suspected coexisting autoimmune pancreatitis (AIP). The patient presented with a chief complaint of icterus and weight loss, and was referred to our institution after a pancreatic lesion was found. Blood test showed elevation of serum bilirubin, hepato-biliary enzyme, glucose and tumor markers, and also high levels of serum IgG4 (344 mg/dl, normal 4.8–105 mg/dl) and anti-DNA antibody (14 IU/ml, normal <6.0 IU/ml). Ultrasonography demonstrated an enlarged pancreas with smooth borders and low internal echo density. Enhanced computed tomography (CT) showed a sausage-shaped pancreas without definitive metastasis to the surrounding lymph nodes and liver. Imaging of the pancreatic duct, including endoscopic retrograde pancreatography (ERP) and magnetic resonance cholangiopancreatography (MRCP), showed stenosis of the main pancreatic duct at the pancreatic head as well as a long segment of narrowing at the body and no dilatation at the tail. Tissues from these stenotic sites and open biopsy from pancreatic body showed infiltrating adenocarcinoma and dense fibrosis. To date, only a small number of reports have described pancreatic carcinoma accompanied with AIP. It is important to confirm diagnosis with histology in cases of suspicious autoimmune pancreatitis, even when the clinical images are compatible with AIP.     

Intrapancreatic pseudoaneurysm associated with pancreatitis mimicking pancreatic tumor

A 48-year-old man, who had suffered a bout of acute pancreatitis in September 2000, was found in March 2001 to have an increased concentration of serum amylase. A tumor in the pancreas body associated with stenosis and prestenotic dilatation of the main pancreatic duct was detected using imaging techniques. Distal pancreatectomy was performed under the diagnosis of pancreatic carcinoma. An intrapancreatic hematoma due to rupture of a pseudoaneurysm of the intrapancreatic artery was found in the resected specimen. This case illustrates how difficult it is to diagnose a small cancerous tumor in the pancreas and the rare presentation of this intrapancreatic pseudoaneurysm, which developed in a patient with a recent history of acute pancreatitis.     

New canine model of chronic pancreatitis due to chronic ischemia with incomplete pancreatic duct obstruction

A new experimental model of chronic pancreatitis was produced by a combination of chronic ischemia and incomplete obstruction of the pancreatic duct. Ischemia was induced by ligation and separation of branches flowing into the left pancreatic lobe from the splenic artery. Incomplete ductal obstruction was achieved by ligation and separation of the minor pancreatic duct and placement of a polyethylene tube in the major pancreatic duct. Macroscopic examination at 6 months after model preparation showed that the pancreas was hard, with severe inflammatory change. In the secretin test, the flow rate of pancreatic juice, amylase output and bicarbonate concentration were significantly reduced as compared with the controls. Pancreatography revealed dilatation and meandering of the major pancreatic duct and poor visualization of its secondary and tertiary bifurcations. The histopathological findings consisted of a decrease in the pancreatic parenchyma, replacement of fat, severe inflammatory cell infiltration, extensive fibrosis and tubular complexes. This model most closely resembles human chronic pancreatitis, and is a very useful instrument.     

Intrapancreatic pseudoaneurysm associated with pancreatitis mimicking pancreatic tumor

A 48-year-old man, who had suffered a bout of acute pancreatitis in September 2000, was found in March 2001 to have an increased concentration of serum amylase. A tumor in the pancreas body associated with stenosis and prestenotic dilatation of the main pancreatic duct was detected using imaging techniques. Distal pancreatectomy was performed under the diagnosis of pancreatic carcinoma. An intrapancreatic hematoma due to rupture of a pseudoaneurysm of the intrapancreatic artery was found in the resected specimen. This case illustrates how difficult it is to diagnose a small cancerous tumor in the pancreas and the rare presentation of this intrapancreatic pseudoaneurysm, which developed in a patient with a recent history of acute pancreatitis.     

Pressure of papillary sphincter zone and pancreatic main duct in patients with chronic pancreatitis in the early stage

We measured pressures of the papillary sphincter zone and pancreatic main duct endoscopically in 20 control subjects and in 38 patients with chronic pancreatitis without papillary stenosis, including 19 cases believed to be in the early stages of chronic pancreatitis. There was no significant difference between control subjects and patients with chronic pancreatitis without papillary stenosis in the motility of the sphincter of Oddi. The pancreatic main ductal pressure was significantly higher in the patients in the early stage of chronic pancreatitis (35.7 +/- 9.1 mm Hg (mean +/- SD) in patients suspected of having chronic pancreatitis and 44.9 +/- 20.4 mm Hg in minimal-change chronic pancreatitis) than in the controls (16.2 +/- 8.7 mm Hg). The viscosity of pure pancreatic juice of patients with chronic pancreatitis (5.0 centi-Poise (cP] in the basal secretory phase was significantly higher than that of the controls (1.32 cP). These data suggest that endoscopic measurement of pancreatic ductal pressure is useful for diagnosis of the early stages of chronic pancreatitis.     

丝留置切割法在慢性胰腺炎胰管困难性 插管中的价值初探

目的 评价导丝留置切割法对困难性胰管狭窄再扩张的安全性及有效性。方法 收集2017年11月—2019年4月期间在南京鼓楼医院消化内科行经内镜逆行胰胆管造影术(endoscopic retrograde cholangiopancreatography, ERCP) 胰管支架置入失败,狭窄胰管仅能允许导丝通过并留置导丝的慢性胰腺炎患者资料,探讨导丝留置切割对于困难性胰管狭窄的扩张作用,分析导丝留置时间、再次ERCP胰管支架置入成功率、术后淀粉酶水平、导丝留置近期并发症及随访结果。结果 共计5例患者ERCP术中胰管狭窄扩张失败后留置导丝,平均留置导丝2.4 d后,再次行ERCP,胰管狭窄部位均可成功扩张,并置入胰管支架。并发症发生方面,仅有1例患者首次ERCP术后发生急性胰腺炎,经过对症治疗好转。结论 导丝留置切割是一种简单、安全、有效的胰管狭窄扩张新方法,对处理慢性胰腺炎胰管困难性插管具有重要的临床价值。