Surgical Management of Chronic Pancreatitis

Transcription

1 George H. Sakorafas, M.D., George Peros 4th Department of Surgery, Athens University, Medical School, ATTIKON University Hospital, Athens, Greece INTRODUCTION Although initial management of patients with chronic pancreatitis is always conservative, a selected subgroup of them will require surgical treatment at some time during the natural history of the disease. 1,2 Despite recent progress in our understanding of the pathophysiology of pain in chronic pancreatitis, the wide avaliability of modern imaging methods and the increasing safety of pancreatic surgery (including major pancreatic resections, such as pancreatoduodenectomy), the management of these patients remains a challenging problem for the surgeon. This is not only due to the inability of surgery to achieve complete pain relief in all these patients, but also to the metabolic consequences of both pancreatic surgery and the underlying chronic pancreatitis, as well as to the chronic alcoholism, which represents one of the commonest etiologies of the disease. The combination of these factors may result in significant long-term morbidity and even mortality, especially among the non-compliant, medically unreliable alcoholic patients. 3 To achieve the best results while at the same time minimizing both early and late morbidity and mortality, careful patient selection should be performed. 4-6 This patient selection should be based mainly on the structural changes of the pancreas and adjacent organs, as demonstrated on imaging methods and vertified at surgery. This review summarizes our current diagnostic and therapeutic approach in patients with chronic pancreatitis. Address for the correspondence: G.H. Sakorafas, M.D., Ph.D, Arkadias 19-21, Gr Athens, Greece Tel: , Fax: georgesakorafas@yahoo.com 71

2 G.H. Sakorafas THE PATHOPHYSIOLOGICAL BASIS OF SURGERY IN CHRONIC PANCREATITIS Pain is the most common clinical presentation and the main indication for surgery in chronic pancreatitis. 4,6 The etiopathology of pain appears to be multifactorial and complex. Two complementary theories offer the physiological basis for surgery in chronic pancreatitis: a. Neural inflammation theory: Pancreatic nerves, abundant in the pancreatic Parenchyma and peripancreatic tissues, are involved in the fibroinflammatory process that characterizes chronic pancreatitis. 7,8 As a consequence, anatomical and functional changes occur in the nerves, mainly in the perineural sheath. 9 Neurotransmitters and a variety of local noxious agents (i.e., histamine, serotonin, substance P, prostaglandins, bradykinins, cytokines, acidosis, digestive pancreatic enzymes,etc) are released locally and stimulate the pain receptors as a consequence of tissue injury and visceral inflammation, 9,10 thus supporting the role of neural chronic inflammation in the pathogenesis of pain. 11 This theory supports pancreatic resection as a method of surgical treatment of chronic pancreatitis; resectional procedures achieve pain relief by eliminating the diseased (or the most diseased) pancreatic parenchyma, thereby disrupting the neural pathway transmitting the pain stimulus. b. Pancreatic compartment theory: Antoher alternative hypothesis is that increased interstitial and ductal pressure causes a localized visceral compartment syndrome, which may be the cause of pain in chronic pancreatitis. Pancretive nerves sensitized from noxious chemical stimuli are also hypersensitive to mechanical stimuli, such as increased pancreatic pressures. 12 Both pancreatic duct (normally: 7-15 mm Hg, in chronic pancreatitis: mm Hg) and parenchymal tissue hypertension (normally: < 20 mm Hg, in chronic pancreatitis. 13,14 This may be due to fibrosis that envelops the chronically inflamed pancreas and limits the ability of the gland to expand during periods of exocrine secretion and to absorb the pressure caused by the increased ductal volume and pressure. 15 Pancreatic ischemia, resulting from this <<compartment syndrome>> may be involved in the pathogenesis of pain in chronic pancreatitis. 16 An interesting, recently proposed, theory for the pathogenesis of pain in chronic pancreatitis is that the <<pacemaker>> of the disease resides in the pancreatic head. This is not only a result of the relatively large amount of parenchyma located in the pancreatic head, which initiates at least one of the following problems: stenosis of the pancreatic head, which initiated at least one of the following problems: stenosis of the panceatic duct, compression of the distal common bile duct with recurrent clinical and/or subclinical episode of cholangitis, compression or even obstruction of the duodenum and encasement of the retropancreatic vessels. 17 In other words, in chronic pancreatitis the pathogenetically <<crucial triangle>> llies within the head of the pancrad, between the distal common bile duct, the main pancreatic duct, and the superior mesenteric/portal vein. After the mid 80 s, this concept generated intense interest in proximal pancreatectomy in the surgical management of chronic pancreatitis. Improved operative mortalities further encouraged the surgical focus to center on proximal pancreatic resections. Indeed, beginning in the early 1980 s and continuing to the present, mortality rates have declined to <5% in many institutions around the world and several centers have recently reported no hospital mortality in series of pancreatoduodenectomies exceeding 100 cases. 18,19 PREOPERATIVE EVALUATION Preoperative evaluation is the most important part in the surgical decision making process. In addition to the usual examinations, peroperative evaluation of patients with chronic pancreatitis should include the following: 4 1. Confirmation of the diagnosis with as much certanity as possible. Other causes of abdominal pain should be carefully excluded. 2. Evaluation of pancreatic function (both endocrine and exocrine). This is a important step, since major pancreatic resections usually result in the apperence continuing chronic inflammation in the remaining pancreatic parenchyma (chronic pancreatitis of the remnant). Pancreatic insufficiency is a major cause of significant morbidity and sometimes mortality (especially among alcoholics) and dramatically alters the quality of life in these patients. 3. Evaluation of the nutritional status of the patient and determination of need for preoperative nutritional support, which is only rarely required, however. 4. Determination of addiction (frequent or regular narcotics use) or continued alcohol usage. Continued alcohol usage is associated with poor results of surgery, higher late morbidity and mortality, and is considered by some as a contraindication for surgery for chronic pancreatitis. Chronic drug addiction usually requires special management by psychiatrists prior to surgery. 5. The study of the pancreas and adjacent organs using modern imaging methods remains the most important part in the preoperative evaluation of the patient with chronic pancreatitis. To determine the structural Austral - Asian Journal of Cancer ISSN , Vol. 6, No.1, January 2007 pp

3 changes of the pancreas and adjacent organs, a variety of imaging methods are currently in use, including ultrasonography (both abdominal and endoscopic), abdominal computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), and/ or magnetic resonance imaging (MRI). 20 Although abdominal ultrasonography is a useful diagnostic tool in the initial diagnostic evaluation of the patient with biliary-pancreatic disorders, this method has many limitations in pancreatic imaging. Endosscopic ultrasonography is an attreactive slternative diagnostic method, which has a much higher sensitivity(~ 88 %) and specificity (~ 100 %) 21,22 However, experience remains relatively limited and the mathod is not widely avilable in the clinical practice. Abdominal computed tomography (CT) remains the << gold standard>> in the evaluation of the patient with complex pancreatic disorders, including chronic pancreatitis. 23 Computed tomography images (shows) the pancreatic parenchyma, the presence of complications from the pancreas itself or the adjacent organs (such as common bile duct obstruction, pseudocyst (-s), duodenal stenosis, splenic vein thrombosis, etc). Endoscpic retrograde cholangiopancreatography is an invaluable tool in the diagnostic evaluation of patients with chronic pancreatitis. 24 ERCP delineates the anatomy of the pancreatic ductal and the biliary tract system. In addition to diagnostic implications, ERCP may have therapeutic interest in selected patients with chronic pancreatitis Magnetic resonance imaging (MRI) is an attractive diagnostic alternative, which may offer the possibility of <<all-in-one>> examination. Indeed, MRI will image the pancreatic parenchyma, the pancreatic ductal and biliary tract system (MRCP) and the peripancreatic vasculature (magnetic angiography) Although today is relatively rarely performed, probably its use will expand in future and perhaps by the start of the new millennium MRCP will replace diagnostic ERCP as the modality of choice for imaging the biliary and pancreatic ductal system. Important information usually result from this diagnostic evaluation, including the presence or not of duct dilatation (defined as main pancreatic duct diameter of more than 7 mm) and strictures of the pancreatic duct, the main localization of the disease (i.e., jead vs. tail vs. diffuse involvement), the presence of an inflammatory mass and its location (i.e.head/body, or tail), and the presence or not of complications from the pancreas and /or adjacent organs (such as common bile duct stenosis, splenic vein thrombosis resulting in sinistral portal hypertension, duodenal stenosis, pseudocystic disease, etc.). To select the optimal surgical procedure for the individual patient with chronic pancreatitis, the surgeon should take into consideration all these information from the preoperative evaluation. SURGICAL DECISION-MAKING The following types of surgery are avaliable as options in the surgical management of chronic pancreatitis: resectional procedure, drainage procedure, and the newer organpreserving>> or <<core-out>> procedure (see proximal pancreatectomy), which combine a minimal resection with drainage of the remaining pancreas. 4,6,8 Thoracoscopic splanchnicectomy is a <<minimally invasive>> approach recently proposed for the management of pain in chronic pancreatitis and is currently under investigation. 31 RESECTIONAL PROCEDURES Resectional procedures are usually performed in the absence of duct dilatation (<<Small-duct disease>>, main pancreatic duct diameter < 7 mm). 3-5, 15 The type of pancreatic resection should be determined mainly depending on the main localization of the disease. For small duct, tail-dominant disease, a distal pancreatectomy (with or without spleen preservation) should be performed. Proximal pancreatectomy is indicated for head-dominant small-duct disease. If the pancreas is diffusely involved by the fibro-inflammatory process, a proximal pancreatectomy is still the preferred type of surgery. This approach is based on the concept of the <<pacemaker>> residing in the pancreatic head, as previously noted. In addition to pancreatoduodenectomy (usually with preservation of the pylorus), proximal pancreatectomy includes the newer organ-preserving pancreatic resections, the Begar procedure (duodenum- preserving resection of the head of the pancreas), 32,33 and the Frey procedure (local excision of the pancreatic head with lateral pancreatojejunostomy). 34 Pancreatoduodenectomy achieves pain relief in a significant persentage of patients with chronic pancreatitis (81% at five years ) with acceptable mortality and morbidity. 35 The newer organ-preserving proximal pancreatectomies (i.e., Beger and Frey procedures) offer the advantages of drainage, i.e. preservation of pancreatic function and limited operative trauma, without the burdens of radical resections, i.e. significant operative and long-term morbidity At the same time the critical pancreatic head region is complications from adjacent organs. Good result oncerning pain relief similar or even superior to pancreatoduodenectomy have been reported and await cconfirmation by other groups. Theoretically, these procedures offer some advantages as a result of the preservation of the normal upper gastrointestinal continuity. Total pancreatectomy is a less attractive option. 6 It is invariably associated wih pancreatic insufficiency (both Austral - Asian Journal of Cancer ISSN , Vol. 6, No.1, January 2007 pp

4 G.H. Sakorafas endocrine and exocrine), that significantly alters quality of life and results in significant morbidity and potentially mortality, especially among alcoholics. 4,6 For these reasons, the role of total pancreatectomy in the surgcal management of chronic pancreatitis has been questioned and generally it is perfomed as completion pancreatectomy after a previously failed pancreatic resection. A specific indication for pancreatic resection in patients with chronic pancreatitis is the suspicion for underlying malignancy. The association of chronic pancreatitis with pancreatic cancer is well-known. 36 The differential dignosis may be very diffcult, since pancreatic cancer may present as chronic pancreatitis, but also because pancreatitis may be associated with inflammatory masses mimicking cancer of the pancreas. 36 accurate differential diagnosis is usually impossible before surgery and sometimes the diagnosis is usually impossible before surgery and sometimes the diagnosis can be accurately be made on specimens of radical pancreatic resections for persumed malignancy. 4,6 Therefore, the surgeon should keep in his/her mind a high index of suspicion for underlying malignancy, especially when an inflammatory mass is associated with a dominant stricture of the pancreatic duct.in these cases a radical pancreatic resection should be performed, which is appropriate for both chronic pancreatitis and pancreatic cancer. Therefore, for inflammatory massess in the head of the pancreas suspicious for pancreatic cancer, pancreatoduoodenectomy should be preferred over the newer organ-preserving procedures, since it achieves radical resection of the suspicious lesion. 36 DRAINAGE PROCEDURES Traditionally, the presence of duct dilatation is considered as an indication for ductal drinage through lateral pancreatojejunostomy (partington-rochelle procedure). 3-6 This is a safe operation, with minimal early and late morbidity and mortality, and perserves whichever panvreatic function remains at the time of surgery, while at the same time achieves pain relief in a significant persentage of patients (60-85 % at 5 years). 6,37,38 The once popular Du Val (drinage) procedures has now fallen into disfavor and is only rarely perfomed, at least as orginally described. 39 Interestingly, based on the pathophysiology of pain in chronic pancreatitis as a result of compartment syndrome of the pancreas, a new approach has been recently described aiming to perform drinage of the pancreatic duct even in small duct disease which involves a v V-shaped excision of the ventral pancreas; thus a lateral pancreatojejunostomy can be perfomed even in the absence of pancreatic duct dilatation. 40 The concept that the pain of chronic pancreatic capsule, has been used to justify this approach. Obviously, this approach is practically especially attractive, especially in yhe patient with compensated but borderline pancreatic function, since typically these patients are selected to undergo a resectional procedure. 3 At the present time, experience remains limited and the results of the three published studies are contradictory DENERVATION PROCEDURES Denervation procedures have been described and evaluated in attempt to extrinsically denervate the pancreas. These approaches include intraoperative chemical splanchnicectomy (celiac plexus block), surgical splanchnicectomy and ganglionectomy, selective pancreatic denervation, denervated splenopancreatic flap, segmental pancreatic autotransplantation. 8 Despite initial enthusisam, these procedures have proved disappointing, with unpredictable results and failures for a durable, long-term relief of pain and therefore are now rarely performed in patients. However, the recent explosion of minimally invasive surgery renewed the interest in surgical denervation of the pancreas using thoracoscopic approaches to transection of yhe greater splanchnic neves Short-term results were encouraging (~80 % relief of pain), 44 but longterm results are non-existent. Endosonography offers another approach for chemical spanchnicectomy during endoscopy However, experience remains limited at the present time and longer follow-up is needed to assess longterm efficacy. REFERENCES 1. DiMagno EP. Enzymes and endotherpy in chronic pancreatitis. In: The Society for Surgery of the Alimentary Tract Postgraduate Course, 1998, New Orleans, May 1998, pp Cremer M, Deviere j, Delhayae M, Vandermeeren A, Baize M. Non-surgical management of severe chronic pancreatitis. Scand J Gastronterol 1990; 175: Sarr MG, Sakorafas GH. Incapacitating pain of chronic pancreatitis: a surgical perspective of what is known and what needs to be known. Gastrointest Endosc 1999; 49: S85-S Ho HS, Frey CF. Current approach to the surgical management of chronic pancreatitis. The Gastroenterologist 1997; 5: Gadacs TR. SSAT patient care guides. Practical guidelines for patients with gastrointestinal surgical diseases. Surgical treatment of chronic pancreatitis. J Gastrointest Surg 1998; 2: Sakorafas GH, Farmell BF, Farley DR, Rowland CM, Sarr MG. Long term results of surgery for chronic pancreatitis. Int J Pancreatol 2000; 27: Malfertheiner P, Dominguz-Munoz JE, Buchler MW. Chronic pancreatitis: Management of pain. Digestion 1994; 55(suppl 1): Wong GY Sakorafas GH, tsiotos GG, sarr mg. Palliation of pain in chronic pancreatitis: use of neural blocks and neurotomy.surg Clin North Am 1999; 79: Blockmann DE, Buchler M, Malfertheiner P, Beger HG. Analysis of nerves in chronic pancreatitis. Gastroenterology 1988 ;94 Austral - Asian Journal of Cancer ISSN , Vol. 6, No.1, January

5 Keith RG, Keshavje SH, kerenyil NR. Neuropathology of chronic pancreatitis in humans. Can J Surg 1985; 28: Buchler MW, Weihe E. Distribution of neurotransmitters in afferent numan pancreatitis nerves. Digestion 1988; 38: Gebhardt GF. Visceral pain mechanisms. In: Chapman CR, Foley KM (Eds). Current and emerging issues in cancer pain. Newyork, Raven press, 1993, pp Jalle RP, Aslam M, Williamson RCN. Pancreatic tissue and ductal pressures in chronic pancreatitis. Br J Surg 1991; 78: Ebbehoj N, Borely L, Evaluation of pancreatic tissue pressure and pain in chronic pancreatitis: a longitudinal study. Scand J Gastroenterol 1990; 25: Alvarez C, Widdison AL, Reber HA. New perspectives in the surgical management of chronic pancreatitis. Pancreas 1991; 6 (suppl 1): S 76-S Karanjia ND, Widdison AL, Leung F, Alvareze C, Lutin FJ, Reber HA. Compartment syndrome in experimental chronic obstructive pancreatitis: effect of decompressing the main pancreatic duct. Br J Surg 1994; 81: Izbicki J. Pancreatic resection in chronic pancreatitis. In: The Society for Surgery of the Alimentary Tract Postgraduate Course 1998, New Orleans, May 1998, pp Pellegrini CA, Heck CF, Raper S. Way LW. An analysis of the reduced morbidity and mortality rates after pancreaticoduodenectomy. Arch Surg 1989; 124: Trede M, Schwall G, Saeger H-D. Survival after pancreatoduodenectomy: 118 consecutive resection without an operative mortality. Ann Surgery 1990; 211: Bank S, Chow KW. Diagnostic tests in chronic pancreatitis. Gastroenterologist 1994;2: Buscail I, Escourrou J, Moreau J, Delvaux M, Louvel D, Lapeyre F, Tregant P, Flexinos J.Endoscopic ultrasonography in chronic pancreatits: a comparative prospective study with conventional ultrasonography, computed tomography, and ERCP. Pancreas 1995; 10: Bhutani MS. Endoscopic ultrasound in pancreatic disease. Indications, limitations and the future. Gastrointest Clin North Am 1999; 28: Thoeni RF, Blankenberg F. Pancreatic imaging. Computed tomography and magnetic resonance imaging. Radiol Clin North Am 1993; 31: Axon AT. Endoscopic retrograde chonangiopancreatography in chronic pancreatitis. Radiol Clin North am 1989; 27: Pap A, Topa L, Berger Z, Flautner L, Varro V. Pain relief and functional recovery after endoscopic interventions for chronic pancretitis. Scand J Gastroenterol Suppl 1998; 228: Carr-Locke DL. Endoscopic therapy of chronic pancreatitis. Gastrointest Endosc 1999; 49 (3 Pt 2): S77 S Schmalz MJ, Greenen JE. Therapeutic pancreatic endoscopy. Endoscopy 1999;31: Coakley FV, Schwartz LH. Magnetic resonance chonalgiopancreatography.j Magn Reson Imaging 1999;9: Sica GT, Braver J, Cooney MJ, Miller FH, Chai JL, Adams DF. Comparison of endoscopic retrograde cholangiopancretography with MR cholangiopancreatography in patients with pancreatits. Radiology 1999; 210: Fulcher AS, Turner MA, Zfass AM. Magnetic resonance cholangiopancreatography: a new technique for evaluating the biliary tract and pancreatic duct. Gastroenterologist 1998:6: Maher JW, Johlin FC, Pearson D. Throcoscopic splanchnicectomy for chronic pancreatitis pain. Surgery 1996; 120: Izbicki JR, Bloechle C, knoefel WT, Kuechler T, Binmoeller KF, Broelsch CE. Duodenum preserving resection of the head of the pancreas in chronic pancreatitis. A prospective randomized trial. Ann Surg 1995; 221: Buchler MW, Friess H, Bittner R. Dupdenum-preserving pancreatic head resection. Long-term results. J Gastrointest Surg 1997; 1: Frey CF, Amikura K. Local resection of the head of the pancreas combined with longitudinal pancreatojejunostomy in the management of patients with chronic pancreatitis. Ann Surg 1994; 220: Sakorafas GH, Farnell MB, Nagorney DR, Rowland C, Sarr MG. Pancreatoduodenectomy for chronic pancreatits. Arch Surg (In Press). 36. Sakorafas GH, Farnell MB, Nagorney DR, Rowland C, Sarr MG. Pancreatic cancer in patients with chronic pancreatitis: a challenge from a surgical perspective Cancer Treatm Rev 1999; 25: Greenlee HB, Prinz RA, Aranha GV. Long-term results of side to- side pancreaticojejunostomy. World J Surg 1990;14: Drake DH. Frey WJ. Ductal drainage for chronic pancreatitis. Surgery 1989; 105: Sakorafas GH, Sarr MG. Changing trends in surgery for chronic pancreatitis. Eur J Surg (In Press) 40. Izbicki JR, Bloechle C, Broerig DC, Kuechlet T, Broelsch CE. Longitudinal V-shaped excision of the ventral pancreas for small duct disease in servere chronic pancreatitis: prospective evaluation of a new surgical procedure. Ann Surg 1998; 227: Delcore R, Rodriguez FJ, Thomas JH, Forster J, Hermeck AS. The role of pancreatojejunostomy in patients without dilated pancreatic ducts. Am J Surg 1994; 168: Rios GA, Adams DB, Yeoh K-G, Tarnasky PR, Cunninghem JT, Hawes RH. Outcome of lateral pancreaticojejunostomy in the management of chronic pancreatitis with non-dilated ducts. J Gastrointest Surg 1998; 2: Andren Sandberg A, Zoucas E, Ihse I, Gyllstedt E, Lillo-Gil R. Thoracoscopic exsision of the splanchnic nerve: an effective treatment in chronic pancreatic pain. Lakartidningen 1995; 92: Bradley EL III, Reynhout JA, Peer GL. Thoracoscopic splanchnicectomy for <<small duct>> chronic pancreatitis: case selection by differential epidural analgesia. J Gastrointest Surg 1998; 2: Kusano T, Miyazato H, Shiraishi M, Yamada M, Matsumoto M, Muto Y. Thoracoscopic thoracic splanchnicectomy for chronic pancreatitis with intractable abdominal pain. Sug Laparosc Endosc 1997; 7: Maher JW, Johlin FC, Pearson D. Thoracoscopic splanchnicectomy for chronic pancreatitis pain. Surgery 1996; 120: Wiersema MJ, Wiersema LM. Endosonography guided celial plexus neurolysis. Gastrointest Endosc 1996; 44: Gress F, Ikenberry S, Guttlieb K. A randomized prospective trial of endoscopic ultrasound (EUS) guided celiac plexus block for the control of pain due to chronic pancreatitis (abstract). Gastrointest Endosc 1996; 43: Faigel DD, Veloso KM, Long WB. Endosonography-guided celiac injection for abdominal pain due to chronic pancreatitis (letter). Am J Gastroenterology 1996; 91: Austral - Asian Journal of Cancer ISSN , Vol. 6, No.1, January