CP primarily always is a disease which requires conservative treatment. Recent studies on long-term progression, however, have shown that the majority of patients with CP will not become pain-free even after the disease has progressed for more than 10 years. The chronic pain syndrome and complications such as bile duct stenosis, duodenal, pancreatic duct or vascular obstruction or symptomatic pancreatic pseudo-cysts frequently require surgical intervention during progression. In the past, surgical procedures involving drainage as well as resection have been employed successfully.
One of the negative aspects of bypass surgery is the fact that malignancy cannot be safely excluded. Another factor is the lower frequency of long-term freedom from pain of only 0 to 42% after an average of 41 months [8
]. Complications associated with a tumor, such as duodenal or bile duct stenoses, cannot be treated sufficiently by this procedure, either [10
]. This procedure is only efficient if there is a single obstruction between the pancreatic duct and the ampulla vateri.
Even today, partial pancreaticoduodenectomy according to Whipple is considered the standard therapy for unclear tumors of the pancreatic head [11
]. Drawbacks of the operation are, in addition to a high morbidity rate of up to 50% [12
], the frequent occurrence of postoperative diabetes and maldigestion after pancreatectomy [11
]. Loss of disease-free neighboring organs is an additional disadvantage of partial pancreatectomy [12
] and frequently leads to dumping complaints and episodes of cholangitis [11
]. The pylorus-preserving modification of the traditional Whipple procedure failed to lead to a considerable improvement of the adverse aspects [12
The Frey procedure combines a longitudinal pancreaticojejunostomy with longitudinal opening of the pancreatic duct and a wedge-shaped local resection of the pancreatic head [13
]. This method is also referred to as "extended drainage procedure" [12
], which combines the advantages of the two fundamental surgical principles, drainage and resection. This method is considered to be simpler and faster than pancreatic head resection according to Beger, because the pancreatic head is not detached and thus there is no danger of hemorrhages from the portal vein [13
]. Advantages of this organ-preserving operative technique are said to be long-term freedom from pain, low morbidity and mortality compared to the Whipple procedure and a low rate of newly occurring diabetes mellitus [10
The results of our own and other studies show that both the Frey procedure as well as partial pancreaticoduodenectomy are capable of improving chronic pain symptoms in CP. As far as later endocrine and exocrine pancreatic insufficiency is concerned, however, the extended drainage operation according to Frey proves to be advantageous compared with the traditional resection procedure (Table ).
Comparison of study results relating to the Frey procedure and partial pancreaticoduodenectomy.
In this context, the preservation of the gastroduodenal passage and bile duct continuity seems to be of decisive importance for the regulation of exocrine secretion efficiency of the pancreas and glucose metabolism [15
]. In the Frey group, two thirds of the patients were completely rehabilitated after surgery, both occupationally and socially. Patients with preoperative organ complications, such as duodenal stenosis and a tumor of the pancreatic head, postoperatively were free from symptoms in 90% of the cases. Partial pancreaticoduodenectomy is the most frequently applied surgical method in patients with associated complications in neighboring organs [10
]. It not only leads to far longer surgery, intensive care monitoring and hospitalization times, but also necessitates blood transfusions more frequently and results in a twice as high morbidity rate compared to the Frey patients (Table ). Occupational and social rehabilitation is limited. Under these circumstances, the radical nature of the surgical procedure must be called into question if chronic inflammatory disease is benign, particularly since our data confirm the experience that the aims of therapeutic intervention in CP are safely achieved by the Frey procedure.
Comparison of study results relating to the Frey procedure and to partial pancreaticoduodenectomy.
The comparison of study results is difficult, not only because there is no agreement on the assessment of pain intensity, but also due to ambiguous diagnosis criteria. In our patient group, it leads to an unexpectedly high new manifestation rate of exocrine pancreatic insufficiency of 30%. A diagnosis of CP is made clinically and based on medical history, and frequently only after episodes of complaints have recurred for years. The situation is similar for the diagnosis of exocrine pancreatic insufficiency, although specific and sensitive functional tests exist for the confirmation of a disturbance of pancreatic function. Since in CP, symptomatic maldigestion as well as confirmed exocrine insufficiency represent an indication for pancreatin therapy [16
], the complex functional tests hardly bear any therapeutic consequence and are frequently not carried out at all - this also applied to our patients. Although visual diagnosis of steatorrhea strongly depends on the experience of the observer, it is unacceptably bad, especially if characteristics are not very pronounced or the quantity of stools is small [17
]. Therefore, the secretin-pancreozymin test is considered the gold standard in the diagnosis of exocrine pancreatic insufficiency [18
The ratio of pancreatic insufficiency in fact newly occurring postoperatively can only be determined if an adequate diagnosis was made before surgery [19
]. This ratio is also erroneous and too high if postoperative enzyme therapy is conducted prophylactically and without confirmation of the diagnosis. However, a placebo-controlled study substantiated the necessity and efficiency of long-term pancreatin therapy initiated directly after surgery for patients operated on according to the Frey procedure [20
A comparison between patients having undergone surgery and patients with a conservative therapeutic regime is unreliable because the former were in a worse condition preoperatively and progression of the disease was expected. Nevertheless, the results of such a comparative study [21
] indicate no major differences in pain development, and overall freedom from pain amounts to 35% after an average disease duration of 11.2 years. After a median disease progression time of 9.7 years, 50% of our patients were completely pain-free. Nevertheless, therapeutic caution is not justified in long-term morphine therapy [16
]. Therapy of long-term severe pain symptoms remains the domain of surgery [22
In summary, for patients with chronic pancreatitis, freedom from pain as well as metabolic changes are of decisive importance. Compared with other traditional surgical techniques, Frey's drainage procedure with the additional local resection of the pancreatic head seems to offer advantages with respect to long-term freedom from pain and the low risk of a surgery-induced deterioration of pancreatic function. From our point of view, Frey's procedure can thus be recommended as a new standard method for surgical therapy of CP. This method provides us with an organ-preserving surgical principle for treating the complications of CP without deteriorating the situation for the patient.