J Gastrointest Surg DOI 10.1007/s11605-013-2418-8
REVIEW ARTICLE
Pancreaticoduodenectomy After Bariatric Surgery: Challenges and Available Techniques for Reconstruction Ioannis Hatzaras & Teviah E. Sachs & Matthew Weiss & Christopher L. Wolfgang & Timothy M. Pawlik
Received: 29 September 2013 / Accepted: 13 November 2013 # 2013 The Society for Surgery of the Alimentary Tract
Abstract Introduction Obesity is an epidemic in the USA, with approximately 7 % of the population considered morbidly obese (BMI>40 or >35 with significant comorbidities). Discussion Weight loss surgery is recognized as a durable solution to both obesity and obesity-associated morbidities. With an increasing number of pancreatic lesions being discovered on cross-sectional imaging, the pancreatic surgeon is increasingly likely to encounter patients with prior bariatric surgery who are in need of pancreaticoduodenectomy. As such, surgeons need to be familiar with the various bariatric operations, as well as the manner in which to handle prior bariatric reconstructions at the time of pancreatic surgery. Literature on this topic, however, is scarce with only a handful of small case series. Conclusion We herein review the different operations performed for weight loss, as well as provide an overview of the available operative approaches for reconstruction after pancreaticoduodenectomy in postbariatric surgical patients. Keywords Obesity . Bariatric . Whipple . Reconstruction
Introduction Obesity is second only to smoking as the leading cause of preventable death in the USA.1 Two-thirds of US citizens are overweight [body mass index (BMI)>25 kg/m2], half of whom are considered obese (BMI>30 kg/m2) and approximately 10 % are morbidly obese (BMI >40 or >35 with significant comorbidities). The medical costs attributable to obesity in the USA nears $200 billion or over 20 % of all medical expenditures.2 Beyond cardiovascular, musculoskeletal, and endocrine effects, there is mounting data that obesity increases the risk of cancer.3,4 It has been calculated that for Ioannis Hatzaras and Teviah E. Sachs contributed equally to the production of this manuscript. I. Hatzaras : T. E. Sachs : M. Weiss : C. L. Wolfgang Department of Surgery, Johns Hopkins Hospital, Baltimore, MD, USA T. M. Pawlik (*) Department of Surgery, Blalock 688 600 N. Wolfe Street, Baltimore, MD 21287, USA e-mail: [email protected]
each 5 kg/m2 increase in BMI the lifelong relative risk for pancreatic cancer increases by 13–18 %.3,4 Weight loss surgery has been recognized as a durable solution to both obesity and obesity-associated morbidities.5 It is unknown however, whether the relative risk of cancer is reduced. Still, an increasing number of individuals are undergoing bariatric procedures, and many of these patients have crosssectional imaging during follow-up. This frequent surveillance coupled with improvements in high definition imaging, has led to the increased diagnosis of incidental pancreatic lesions among bariatric patients. Unfortunately, the literature on these patients is limited to a handful of small case series.6–10 Barbour et al. looked at five patients undergoing pancreatic resection for benign disease (chronic pancreatitis, serous cystadenoma, and islet hyperplasia). Moreover, none included duodenal resection, and only two required pancreatic drainage. Both Nikfarjam et al. and Khithani et al. reported case series, each on two patients in whom pancreatoduodenectomy was performed after gastric bypass. In both series, the remnant stomach was resected with the specimen. The remaining literature relies on isolated case reports. As expected, consensus on whether completion gastrectomy should be performed, the route of pancreaticobiliary drainage and what to do with the prior roux limb is subject to debate. As for the management of patients who require pancreaticoduodenectomy after less common bariatric
J Gastrointest Surg
operations such as biliopancreatic diversion or duodenal switch—once popular operations now largely replaced by gastric bypass—virtually no literature exists. Given that many pancreatic surgeons may not be familiar with bariatric surgical procedures, and surgeons are increasingly encountering these patients, we review the different operations performed for weight loss, and describe the available operative approaches for reconstruction after pancreaticoduodenectomy.
Diagnostic and Perioperative Challenges With the increased identification of pancreatic lesions, the surgeon is increasingly confronted with the added difficulty of working up and diagnosing patients with prior bariatric surgery. CT and MRI scanning are the gold standard for the diagnosis of pancreatic lesions. However, on imaging, patients who have undergone prior bariatric surgery can be difficult for the radiologist to assess, and their new anatomy can often be confusing.11 In many patients, the specifics of anatomical reconstruction from their prior operation are unknown. Beyond the reconstructed anatomy, if patients have had complications from their prior operation, the scarring and fibrosis can make identification of the extent of disease more difficult. Gastric bands and prior suture material can also sometimes cause artifactual irregularities that further confuse the picture. Additionally, oral contrast will not fill the biliopancreatic limb in these patients, although in most cases intravenous contrast is sufficient to assess these lesions. Endoscopic assessment of the pancreatic lesion can also present a challenge among patients who have had bariatric surgery. While gastric banding, sleeve gastrectomy, and vertical banded gastroplasty maintain continuity of the proximal gastrointestinal tract, reconstructive procedures such as Rouxen-Y gastric bypass, duodenal switch, and biliopancreatic diversion do not. Endoscopic evaluation of the gastric remnant, duodenum, and distal bile duct, therefore, can be technically difficult.12 At centers with advanced endoscopy, deep enteroscopy, or balloon enteroscopy can be used to access the duodenum and papilla if the length of the Roux limb, when added to the distance from the ligament of Treitz to the jejunojejunal anastomosis, is less than 150 cm.13 If much longer than this, endoscopic access can still be achieved with open or laparoscopic assistance, however this added invasive procedure is rarely recommended or necessary. Transgastric access to the gastric remnant has also been described using a percutaneous endoscopic gastrostomy for access.14 While this route provides the possibility of EUS and biopsy, such measures are rarely necessary. For those patients with a suspicious lesion based on cross-sectional imaging, biopsy is often not necessary or even warranted to proceed with surgical resection.
In a subset of patients who present with clinical jaundice in whom operative intervention is delayed, biliary stenting may be necessary. High bilirubin levels can exacerbate not only the existing malnutrition, but influence and worsen underlying coagulopathy. As described above, endoscopic access for retrograde cholangio-pancreatography (ERCP) is challenging and at many centers, impossible. For patients who are candidates for upfront resection, routine biliary drainage is often not necessary, as drainage can be associated with pancreatitis and subsequent increased risk of wound infection.15 However, for patients in whom neoadjuvant therapy is being considered, relief of biliary obstruction is necessary. For these patients, consideration should be given to percutaneous trans-hepatic biliary stenting. A significant number of patients with pancreatic cancer may have compromised nutritional status with significant weight loss on presentation. While some postbariatric surgery patients may still be obese, these individuals may indeed have nutritional and vitamin deficiencies.16,17 Obstructive jaundice can further exacerbate malabsorption of essential vitamins and nutrients. Due to the nature of the prior bariatric operation, the correction of these nutritional issues can sometimes be difficult. While patients with long pancreatobiliary limbs, such as in long-limb gastric bypass, biliopancreatic diversion, and duodenal switch procedures, have equivalent vitamin absorption as shorter limb patients, postoperative absorption must be addressed. Their inability to absorb lipid and calories is far greater, than their shorter limb counterparts.18,19 In such circumstances, consultation with a dietician can be helpful.
Current Options for Weight Reduction Surgery Roux-en-Y Gastric Bypass Gastric bypass is the most common operation performed for weight loss, comprising approximately 50 % of bariatric operations performed. In the modern era of bariatric surgery, the operation is performed laparoscopically in over 90 % of patients.20 The first step is the creation of a small (approximately 30–50 cm3) proximal gastric pouch that is divided and completely separated from the remaining stomach. A Roux limb of jejunum, approximately 50 cm downstream from the ligament of Treitz, is brought up and a gastrojejunostomy performed to the gastric pouch. The Roux limb can be either anterior to, or posterior to the transverse colon and gastric remnant. The biliopancreatic limb is then anastomosed to the distal jejunum, approximately 120–150 cm from the gastric pouch. This operation acts in both a restrictive capacity to induce weight loss by limiting intake in the small gastric pouch, as well as in a malabsorptive capacity in that it bypasses a large segment of jejunum. Weight loss is rapid during the first 2 years but then often plateaus (Fig. 1a).21
J Gastrointest Surg
Fig. 1 Depiction of anatomy after a Roux-en-Y gastric bypass, b removal of pancreatoduodenectomy specimen with remnant stomach (the pancreatobiliary remnant is too small to be used for reconstruction), c removal of specimen including remnant stomach and entire
pancreatobiliary limb, and d reconstruction using a new pancreatobiliary limb (gray arrows depict direction of enteral flow; orange arrows depict removal of specimen)
Operative approach when performing pancreaticoduodenectomy
in the upper quadrants at the time of surgery. The approach to the abdomen is no different than with any other re-operative surgery. Once the peritoneum has been entered, adhesions should be freed up proximally around the stomach and continued far distally, often beyond the prior entero-enterostomy
Despite the minimally invasive techniques often employed by bariatric surgeons, adhesions, and fibrosis can be encountered
J Gastrointest Surg
site in the event that a new conduit is necessary for reconstruction. In order to help “re-establish” the anatomy for the surgeon, it is often helpful to undertake dissection distal to the gastric pouch first. While the mobilization does not necessarily include the esophageal hiatus, it is important to adequately free up the Roux limb to the gastric pouch in order to assess the body of the pancreas later in the operation. One should proceed with a full mobilization of the duodenum that allows for assessment of the tumor and vascular structures before exploring a hostile left upper quadrant. Special attention should be paid to the gastric remnant. The surgeon should consider performing a completion gastrectomy, en bloc with the specimen, or alternatively the prior gastrojejunostomy can be left intact. While resection of the remnant stomach may allow greater visibility within the operative field, leaving the prior gastrojejunostomy intact obviates the need later of an added anastomosis to drain the gastric remnant. In general, routine completion gastrectomy should be avoided as it complicates the dissection, necessitates an esophagojejunostomy, and may therefore have an impact on subsequent oral intake/ dietary habits. After removing the pancreaticoduodenectomy specimen, the surgeon largely has two options in terms of reconstruction. In those patients with prior gastric bypass whose pancreatobiliary limb is of sufficient length after the pancreatoduodenectomy, one can use this remaining limb to perform the pancreaticojejunostomy and hepaticojejunostomy. In this scenario, the remaining limb is brought through the transverse colon mesentery, in a retrocolic fashion. Sometimes, the pancreaticobiliary limb is not adequate in length or integrity, after removal of the pancreatoduodenectomy specimen (Fig. 1b). Instead, the entire pancreatobiliary limb is resected down to the jejunojejunostomy, and removed with the specimen (Fig. 1c). A new jejunal limb is then brought up and used for the pancreatobiliary reconstruction (Fig. 1d). The roux limb should be of adequate length (≥ 40 cm) to diminish the possibility of reflux cholangitis. However, if significant small bowel has been resected during the operation, creating too long a limb can lead to short bowel syndrome. The reconstruction proceeds normally, once the biliopancreatic limb has been established. As long as the pancreatic duct can be identified, many surgeons would perform the pancreaticojejunal anastomosis by approximating the pancreatic parenchyma to the jejunal serosa using interrupted 3–0 silk sutures for the outer layer. The inner layer brings together pancreatic duct and jejunal mucosa using fine (5–0 or 6–0) interrupted absorbable sutures. Should the pancreatic duct not be identifiable, a small jejunotomy is made and a dunking anastomosis is often employed. In this case, an interrupted inner layer of absorbable sutures are placed approximating the cut edges of the pancreas and jejunum while an outer layer of interrupted non-absorbable sutures brings the jejunal serosa over the pancreas and approximating it to the pancreatic
capsule circumferentially. Typically, the biliary-jejunal anastomosis is performed using a slightly heavier (5–0 or 4–0) absorbable suture in an interrupted fashion. Should the patient’s prior gastrojejunostomy need revision or a new gastrojejunostomy be required, an antecolic reconstruction to the gastric pouch can be performed using a two layered technique in an end-to-side, functional end-to-end fashion, similar to the typical entero-enterostomy described above. In ordering the reconstruction, the surgeon should avoid placing all three anastomoses in anatomic succession—where the gastrojejunostomy precedes the hepaticojejunostomy and pancreaticojejunostomy. Such a reconstruction will allow the passage of partially digested foodstuffs from the stomach in close proximity to the hepaticojejunostomy (Fig. 2), leading to often recurrent and severe cholangitis or pancreatitis. Oftentimes, there will be severely dense adhesions around the gastric remnant making completion gastrectomy difficult. This can be a particularly hard problem when attempting dissection in patients who have had a complicated postoperative course after their initial bypass operation, either due to
Fig. 2 Depiction of reconstruction after pancreatoduodenectomy with completion gastrectomy in a patient who has undergone prior gastric bypass with gastrojejunostomy, pancreaticojejunostomy, and hepaticojejunostomy in series (not recommended). Enteric food stuffs are shown migrating towards the hepaticojejunostomy, leading to cholangitis (white arrow direction of enteral flow)
J Gastrointest Surg
gastrojejunostomy leak or postoperative abscess. In these patients, providing adequate drainage of the gastric remnant during the reconstruction is necessary. In this uncommon scenario, one option is to use the former biliopancreatic limb (Fig. 3) as a caudal, or draining gastrojejunostomy. However, as described above, in many cases, the remaining biliopancreatic limb is not of adequate length, and so a new draining gastrojejunostomy must be brought up, along with the creation of the pancreaticobiliary limb. As stated before, it is important that the surgeon take care not to leave too short a distal small bowel to cause severe malabsorption, nor place the gastrojejunostomy proximal to the biliopancreatic anastomoses, leading to cholangitis. Furthermore, a reconstruction utilizing a pancreaticogastrostomy is discouraged for two reasons. First, with a densely adhesed gastric remnant, it can be very difficult to mobilize the stomach adequately to anastomose the pancreatic remnant. Second, in patients who have undergone a bariatric procedure where the stomach remains in continuity (vertical banded gastroplasty, gastric sleeve, etc.) a pancreatic postoperative leak would preclude oral intake, whereas a separate pancreaticojejunostomy does not. Adjustable Gastric Banding and Vertical Banded Gastroplasty Fig. 3 Depiction of reconstruction after pancreatoduodenectomy in a patient who has undergone prior gastric bypass and whose gastric remnant cannot be resected. In this uncommon scenario, the remnant pancreatobiliary limb is used to drain the gastric remnant in this case. A separate pancreatobiliary limb is brought up for the reconstruction (white arrow direction of enteral flow)
The gastric banding operation involves the placement of an adjustable silicone band around the proximal stomach. The band is attached to a port placed in the subcutaneous tissue of the epigastrum, so that one can gradually adjust the diameter
Fig. 4 Depiction of anatomy a after gastric banding, and b after vertical band gastroplasty (white arrow direction of enteral flow)
J Gastrointest Surg
of the band, by instilling saline through the port, over time. The goal is to create a proximal gastric pouch, which can limit food intake. This operation is faster and carries less morbidity than Roux-en-Y gastric bypass. Nevertheless, weight loss is less pronounced than the gastric bypass operation (Fig. 4a,b). Popularized in the 1980s, vertical banded gastroplasty involves creating a transverse proximal gastric pouch of the upper portion of the lesser curvature of the stomach with a linear stapler. The pouch is only partially resected from the inferior stomach. Subsequently, a restrictive band is placed at the medial portion of the pouch, to control the outlet to the inferior stomach. Surgeons have largely abandoned this technique due to complications related to the band, such as high-grade stenosis of the distal outlet of the gastroplasty, as well as band erosion into the stomach. Nevertheless, there are still patients who may present with vertical banded gastroplasty (VBG) anatomy. Operative approach when performing pancreaticoduodenectomy The silicone band should be removed during their operation, as it can act as a significant nidus for postoperative infection. For
inflatable or adjustable gastric bands, the band should be deflated prior to beginning the operation. Dissection around the port should proceed with caution as intraperitoneal contents will often have scarred in closely below the device, and occasionally the band itself can migrate or erode into the left lobe of the liver. Often, adhesions near the esophageal hiatus from prior exposure will need to be taken down. Once entered into the peritoneal cavity, removing the band should be relatively simple, as it is deflated and unhooks easily. Exposure is of utmost importance in order to remove the band and adequately assess the tissue of the stomach. If, upon removal of the gastric band, gastric erosion is noted, resection or even near-total gastrectomy may be necessary. Careful assessment of the stomach should extend above and below the prior band site—as a missed erosion or injury can lead to leak or fistula, requiring a prompt return to the operating room. Near-total gastrectomy may also be indicated in the patient who has had vertical band gastrostomy. In these patients, the remnant stomach has a keyhole division in place and often proximal dilation due to gastric stenosis. If assessment of the stomach reveals no stenosis or erosion, classic pancreaticoduodenectomy with hemi-gastrectomy can still be employed and is the preferred approach.
Fig. 5 Depiction of anatomy of a gastric sleeve and b reconstruction using pylorus preserving technique (orange arrow depicts removal of gastric remnant)
J Gastrointest Surg
Sleeve Gastrectomy This operation is restrictive in nature only, with resection of the greater curvature of the stomach over a gastroesophageal bougie. The bougie is aligned along the lesser curvature of the stomach and used to size the remnant sleeve of stomach. The medial stomach is converted into a vertical tube by several firings of a laparoscopic stapler along the bougie. Weight loss
is achieved through this technique by limiting the gastric reservoir (Fig. 5a). Operative approach when performing pancreaticoduodenectomy The pancreatoduodenectomy is not affected by this prior operation, other than the scarring in the left upper quadrant.
Fig. 6 Depiction of a biliopancreatic diversion, b duodenal switch with sleeve gastrectomy and c reconstruction of a duodenal switch patient after pancreatoduodenectomy using the remnant pancreatobiliary limb, which is often long enough in these patients (white arrow direction of enteral flow)
J Gastrointest Surg
However, as the left and right gastroepiploic vessels have been ligated previously, these patients have already lost half of the blood supply to the stomach. Consideration should be given to preserving the right gastric artery along with the pylorus during pancreaticoduodenectomy (Fig. 5b) to prevent a low flow state to the stomach.
Biliopancreatic Diversion and Duodenal Switch Biliopancreatic diversion (BPD) was popular predominately in Europe, and it is similar to the gastric bypass operation, as it acts in both a restrictive and a malabsorptive capacity. The first step in the operation is creation of a proximal gastric pouch. The difference compared with the gastric bypass is the addition of a distal gastrectomy. A long roux limb is then used for a gastrojejunostomy, usually in front of both the transverse colon and stomach. In this operation, the jejunojejunostomy is typically further distal than in a gastric bypass, at approximately 100 cm from the ileocecal valve (Fig. 6a,b). Duodenal switch combines characteristics of the sleeve gastrectomy and gastric bypass/biliopancreatic diversion. It acts in both a restrictive and a malabsorptive capacity. The first step of the operation includes a sleeve gastrectomy of the greater curvature over a bougie, so that a long gastric pouch is created. The pyloric outlet is stapled off from the duodenum and the duodenal stump reinforced. A long roux limb is then anastomosed to the pylorus. Similar to BPD, the jejunojejunostomy is further distal than the gastric bypass operation, at approximately 100 cm proximal to the ileocecal valve. This operation also results in excellent weight loss for the patient, but patients are at higher risk for duodenal leak as well as extreme nutritional deficiencies and malabsorption due to the length of the roux limb. As a result, these operations have largely been abandoned in favor of the gastric bypass operation. Operative approach when performing pancreaticoduodenectomy The principles of biliopancreatic anastomoses in these operations are similar to those described above for Roux-en-Y gastric bypass. Due to the complexity of the operation however, these patients’ exploration and resection are even more likely to be impeded by dense adhesions. Whereas with Roux-en-Y gastric bypass the remnant pancreatobiliary limb is sometimes too short to be utilized in reconstruction, in these patients it is usually long enough to allow its use for both the hepaticojejunostomy and pancreaticojejunostomy (Fig. 6c). Patients who have had gastrojejunostomy for bariatric surgery of any kind, whether it be gastric bypass or biliopancreatic diversion, should have their gastrojejunostomy preserved whenever possible. The patient with duodenal switch may however require a revised or new gastrojejunostomy using
the alimentary jejunal limb, if the surgeon decides to perform a completion or near complete gastrectomy.
Conclusion In conclusion, the high rate of imaging in bariatric patients has led to an increase in the diagnosis of incidental pancreatic lesions. The pancreatic surgeon who undertakes pancreaticoduodenectomy in a postbariatric surgery patient must be cognizant of the potential pitfalls that accompany their prior operation. A diligent preoperative investigation of their anatomy as well as obtaining any prior operative notes is recommended. Depending on the prior operation and the hostility of the abdomen, the surgeon has several options for pancreaticobiliary resection and reconstruction.
Disclosures None
References 1. Flegal KM, Carroll MD, Ogden CL, Curtin LR. Prevalence and trends in obesity among US adults, 1999–2008. JAMA : The Journal of the American Medical Association. Jan 20 2010;303(3): 235–241. 2. Finkelstein EA, Trogdon JG, Cohen JW, Dietz W. Annual medical spending attributable to obesity: payer-and service-specific estimates. Health Aff (Millwood). Sep-Oct 2009;28(5):w822-831. 3. Eheman C, Henley SJ, Ballard-Barbash R, et al. Annual report to the nation on the status of cancer, 1975–2008, featuring cancers associated with excess weight and lack of sufficient physical activity. Cancer. May 1 2012;118(9):2338–2366. 4. Wiseman M. The second World Cancer Research Fund/American Institute for Cancer Research expert report. Food, nutrition, physical activity, and the prevention of cancer: a global perspective. The Proceedings of the Nutrition Society. Aug 2008;67(3):253–256. 5. Schirmer B. SPR. The surgical management of obesity. Schwartz’s Principles of Surgery, 9e. F.C. Brunicardi, D.K. Andersen, T.R. Billiar, D.L. Dunn, J.G. Hunter, J.B. Matthews, R.E. Pollock (Eds), Chapter 27. 2010. 6. Nikfarjam M, Staveley-O’Carroll KF, Kimchi ET, Hardacre JM. Pancreaticoduodenectomy in patients with a history of Roux-en Y gastric bypass surgery. JOP: Journal of the Pancreas. 2009;10(2): 169–173. 7. Rutkoski JD, Gagne DJ, Volpe C, Papasavas PK, Hayetian F, Caushaj PF. Pancreaticoduodenectomy for pancreatic cancer after laparoscopic Roux-en-Y gastric bypass. Surgery for Obesity and Related Diseases : Official Journal of the American Society for Bariatric Surgery. Jul-Aug 2008;4(4):552–554; discussion 554–555. 8 . T h e o d o r o p o u l o s I , F r a n c o C , G e r v a s o n i J E , J r. Pancreaticoduodenectomy for pancreatic carcinoma after complicated open Roux-en-Y gastric bypass surgery: an alternative approach to reconstruction. Surgery for Obesity and Related Diseases : Official Journal of the American Society for Bariatric Surgery. Sep-Oct 2012;8(5):648–650. 9. Barbour JR, Thomas BN, Morgan KA, Byrne TK, Adams DB. The practice of pancreatic resection after Roux-en-Y gastric bypass. The American Surgeon. Aug 2008;74(8):729–734.
J Gastrointest Surg 10. Amit S Khithanil, David E Curtis, Christos Galanopoulos, Dhiresh Rohan Jeyarajah. Pancreaticoduodenectomy after a Roux-En-Y gastric bypass. Obesity Surgery. 2008;19(6):4 11. Ni Mhuircheartaigh JAS, Bennett AE, Tyagi G. Imaging features of bariatric surgery and its complications. Semin Ultrasound CT MR. 2013;34(4):13 12. Khashab MAOP. Accessing the pancreatobiliary limb and ERCP in the bariatric patient. Gastrointest Endosc Clin N Am. 2011;21(2):8 13. Schreiner MACL, Gluck M, Irani S, Gan SI, Brandabur JJ, Thirlby R, Moonka R, Kozarek RA, Ross AS. Laparoscopy-assisted versus balloon enteroscopy-assisted ERCP in bariatric post-Roux-en-Y gastric bypass patients. Gastrointest Endosc. 2012;75(4):8 14. Todd H, Baron LMWKS, Lincoln Ferreira EVV, Thomas C. Smyrk. Novel approach to therapeutic ERCP after long-limb Roux-en-Y gastric bypass surgery using transgastric self-expandable metal stents: experimental outcomes and first human case study (with videos). Gastrointestinal Endoscopy. 2012;75(6):5 15. Iacono CRA, Campagnaro T, Bortolasi L, Valdegamberi A, Guglielmi A. Role of preoperative biliary drainage in jaundiced patients who are candidates for pancreatoduodenectomy or hepatic resection: highlights and drawbacks. Annals of Surgery. 2013;257(2):14
16. Gudzune KAHM, Chang HY, Asamoah V, Gadgil M, Clark JM. Screening and diagnosis of micronutrient deficiencies before and after bariatric surgery. Obesity Surgery. 2013;23(10):9 17. Majumder S., Soriano J., Louie Cruz A., Dasanu CA. Vitamin B12 deficiency in patients undergoing bariatric surgery: preventive strategies and key recommendations. Surg Obes Relat Dis. May 2013 2013. doi:10.1016/j.soard.2013.04.017 18. Choban PSFL. The effect of Roux limb lengths on outcome after Roux-en-Y gastric bypass: a prospective, randomized clinical trial. Obes Surg. 2002;12(4):6 19. Orci LCM, Huber O. Short versus long Roux-limb length in Roux-en-Y gastric bypass surgery for the treatment of morbid and super obesity: a systematic review of the literature. 2011;21(6):8. 20. Nguyen NTMH, Magno CP, Nguyen XM, Laugenour K, Lane J. Trends in the use of bariatric surgery, 2003–2008. Journal of the American College of Surgery. 2011;213(2):6 21. Higa K, Ho T, Tercero F, Yunus T, Boone KB. Laparoscopic Roux-enY gastric bypass: 10-year follow-up. Surgery for Obesity and Related Diseases: Official Journal of the American Society for Bariatric Surgery. Jul-Aug 2011;7(4):516–525.
REVIEW ARTICLE
Pancreaticoduodenectomy After Bariatric Surgery: Challenges and Available Techniques for Reconstruction Ioannis Hatzaras & Teviah E. Sachs & Matthew Weiss & Christopher L. Wolfgang & Timothy M. Pawlik
Received: 29 September 2013 / Accepted: 13 November 2013 # 2013 The Society for Surgery of the Alimentary Tract
Abstract Introduction Obesity is an epidemic in the USA, with approximately 7 % of the population considered morbidly obese (BMI>40 or >35 with significant comorbidities). Discussion Weight loss surgery is recognized as a durable solution to both obesity and obesity-associated morbidities. With an increasing number of pancreatic lesions being discovered on cross-sectional imaging, the pancreatic surgeon is increasingly likely to encounter patients with prior bariatric surgery who are in need of pancreaticoduodenectomy. As such, surgeons need to be familiar with the various bariatric operations, as well as the manner in which to handle prior bariatric reconstructions at the time of pancreatic surgery. Literature on this topic, however, is scarce with only a handful of small case series. Conclusion We herein review the different operations performed for weight loss, as well as provide an overview of the available operative approaches for reconstruction after pancreaticoduodenectomy in postbariatric surgical patients. Keywords Obesity . Bariatric . Whipple . Reconstruction
Introduction Obesity is second only to smoking as the leading cause of preventable death in the USA.1 Two-thirds of US citizens are overweight [body mass index (BMI)>25 kg/m2], half of whom are considered obese (BMI>30 kg/m2) and approximately 10 % are morbidly obese (BMI >40 or >35 with significant comorbidities). The medical costs attributable to obesity in the USA nears $200 billion or over 20 % of all medical expenditures.2 Beyond cardiovascular, musculoskeletal, and endocrine effects, there is mounting data that obesity increases the risk of cancer.3,4 It has been calculated that for Ioannis Hatzaras and Teviah E. Sachs contributed equally to the production of this manuscript. I. Hatzaras : T. E. Sachs : M. Weiss : C. L. Wolfgang Department of Surgery, Johns Hopkins Hospital, Baltimore, MD, USA T. M. Pawlik (*) Department of Surgery, Blalock 688 600 N. Wolfe Street, Baltimore, MD 21287, USA e-mail: [email protected]
each 5 kg/m2 increase in BMI the lifelong relative risk for pancreatic cancer increases by 13–18 %.3,4 Weight loss surgery has been recognized as a durable solution to both obesity and obesity-associated morbidities.5 It is unknown however, whether the relative risk of cancer is reduced. Still, an increasing number of individuals are undergoing bariatric procedures, and many of these patients have crosssectional imaging during follow-up. This frequent surveillance coupled with improvements in high definition imaging, has led to the increased diagnosis of incidental pancreatic lesions among bariatric patients. Unfortunately, the literature on these patients is limited to a handful of small case series.6–10 Barbour et al. looked at five patients undergoing pancreatic resection for benign disease (chronic pancreatitis, serous cystadenoma, and islet hyperplasia). Moreover, none included duodenal resection, and only two required pancreatic drainage. Both Nikfarjam et al. and Khithani et al. reported case series, each on two patients in whom pancreatoduodenectomy was performed after gastric bypass. In both series, the remnant stomach was resected with the specimen. The remaining literature relies on isolated case reports. As expected, consensus on whether completion gastrectomy should be performed, the route of pancreaticobiliary drainage and what to do with the prior roux limb is subject to debate. As for the management of patients who require pancreaticoduodenectomy after less common bariatric
J Gastrointest Surg
operations such as biliopancreatic diversion or duodenal switch—once popular operations now largely replaced by gastric bypass—virtually no literature exists. Given that many pancreatic surgeons may not be familiar with bariatric surgical procedures, and surgeons are increasingly encountering these patients, we review the different operations performed for weight loss, and describe the available operative approaches for reconstruction after pancreaticoduodenectomy.
Diagnostic and Perioperative Challenges With the increased identification of pancreatic lesions, the surgeon is increasingly confronted with the added difficulty of working up and diagnosing patients with prior bariatric surgery. CT and MRI scanning are the gold standard for the diagnosis of pancreatic lesions. However, on imaging, patients who have undergone prior bariatric surgery can be difficult for the radiologist to assess, and their new anatomy can often be confusing.11 In many patients, the specifics of anatomical reconstruction from their prior operation are unknown. Beyond the reconstructed anatomy, if patients have had complications from their prior operation, the scarring and fibrosis can make identification of the extent of disease more difficult. Gastric bands and prior suture material can also sometimes cause artifactual irregularities that further confuse the picture. Additionally, oral contrast will not fill the biliopancreatic limb in these patients, although in most cases intravenous contrast is sufficient to assess these lesions. Endoscopic assessment of the pancreatic lesion can also present a challenge among patients who have had bariatric surgery. While gastric banding, sleeve gastrectomy, and vertical banded gastroplasty maintain continuity of the proximal gastrointestinal tract, reconstructive procedures such as Rouxen-Y gastric bypass, duodenal switch, and biliopancreatic diversion do not. Endoscopic evaluation of the gastric remnant, duodenum, and distal bile duct, therefore, can be technically difficult.12 At centers with advanced endoscopy, deep enteroscopy, or balloon enteroscopy can be used to access the duodenum and papilla if the length of the Roux limb, when added to the distance from the ligament of Treitz to the jejunojejunal anastomosis, is less than 150 cm.13 If much longer than this, endoscopic access can still be achieved with open or laparoscopic assistance, however this added invasive procedure is rarely recommended or necessary. Transgastric access to the gastric remnant has also been described using a percutaneous endoscopic gastrostomy for access.14 While this route provides the possibility of EUS and biopsy, such measures are rarely necessary. For those patients with a suspicious lesion based on cross-sectional imaging, biopsy is often not necessary or even warranted to proceed with surgical resection.
In a subset of patients who present with clinical jaundice in whom operative intervention is delayed, biliary stenting may be necessary. High bilirubin levels can exacerbate not only the existing malnutrition, but influence and worsen underlying coagulopathy. As described above, endoscopic access for retrograde cholangio-pancreatography (ERCP) is challenging and at many centers, impossible. For patients who are candidates for upfront resection, routine biliary drainage is often not necessary, as drainage can be associated with pancreatitis and subsequent increased risk of wound infection.15 However, for patients in whom neoadjuvant therapy is being considered, relief of biliary obstruction is necessary. For these patients, consideration should be given to percutaneous trans-hepatic biliary stenting. A significant number of patients with pancreatic cancer may have compromised nutritional status with significant weight loss on presentation. While some postbariatric surgery patients may still be obese, these individuals may indeed have nutritional and vitamin deficiencies.16,17 Obstructive jaundice can further exacerbate malabsorption of essential vitamins and nutrients. Due to the nature of the prior bariatric operation, the correction of these nutritional issues can sometimes be difficult. While patients with long pancreatobiliary limbs, such as in long-limb gastric bypass, biliopancreatic diversion, and duodenal switch procedures, have equivalent vitamin absorption as shorter limb patients, postoperative absorption must be addressed. Their inability to absorb lipid and calories is far greater, than their shorter limb counterparts.18,19 In such circumstances, consultation with a dietician can be helpful.
Current Options for Weight Reduction Surgery Roux-en-Y Gastric Bypass Gastric bypass is the most common operation performed for weight loss, comprising approximately 50 % of bariatric operations performed. In the modern era of bariatric surgery, the operation is performed laparoscopically in over 90 % of patients.20 The first step is the creation of a small (approximately 30–50 cm3) proximal gastric pouch that is divided and completely separated from the remaining stomach. A Roux limb of jejunum, approximately 50 cm downstream from the ligament of Treitz, is brought up and a gastrojejunostomy performed to the gastric pouch. The Roux limb can be either anterior to, or posterior to the transverse colon and gastric remnant. The biliopancreatic limb is then anastomosed to the distal jejunum, approximately 120–150 cm from the gastric pouch. This operation acts in both a restrictive capacity to induce weight loss by limiting intake in the small gastric pouch, as well as in a malabsorptive capacity in that it bypasses a large segment of jejunum. Weight loss is rapid during the first 2 years but then often plateaus (Fig. 1a).21
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Fig. 1 Depiction of anatomy after a Roux-en-Y gastric bypass, b removal of pancreatoduodenectomy specimen with remnant stomach (the pancreatobiliary remnant is too small to be used for reconstruction), c removal of specimen including remnant stomach and entire
pancreatobiliary limb, and d reconstruction using a new pancreatobiliary limb (gray arrows depict direction of enteral flow; orange arrows depict removal of specimen)
Operative approach when performing pancreaticoduodenectomy
in the upper quadrants at the time of surgery. The approach to the abdomen is no different than with any other re-operative surgery. Once the peritoneum has been entered, adhesions should be freed up proximally around the stomach and continued far distally, often beyond the prior entero-enterostomy
Despite the minimally invasive techniques often employed by bariatric surgeons, adhesions, and fibrosis can be encountered
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site in the event that a new conduit is necessary for reconstruction. In order to help “re-establish” the anatomy for the surgeon, it is often helpful to undertake dissection distal to the gastric pouch first. While the mobilization does not necessarily include the esophageal hiatus, it is important to adequately free up the Roux limb to the gastric pouch in order to assess the body of the pancreas later in the operation. One should proceed with a full mobilization of the duodenum that allows for assessment of the tumor and vascular structures before exploring a hostile left upper quadrant. Special attention should be paid to the gastric remnant. The surgeon should consider performing a completion gastrectomy, en bloc with the specimen, or alternatively the prior gastrojejunostomy can be left intact. While resection of the remnant stomach may allow greater visibility within the operative field, leaving the prior gastrojejunostomy intact obviates the need later of an added anastomosis to drain the gastric remnant. In general, routine completion gastrectomy should be avoided as it complicates the dissection, necessitates an esophagojejunostomy, and may therefore have an impact on subsequent oral intake/ dietary habits. After removing the pancreaticoduodenectomy specimen, the surgeon largely has two options in terms of reconstruction. In those patients with prior gastric bypass whose pancreatobiliary limb is of sufficient length after the pancreatoduodenectomy, one can use this remaining limb to perform the pancreaticojejunostomy and hepaticojejunostomy. In this scenario, the remaining limb is brought through the transverse colon mesentery, in a retrocolic fashion. Sometimes, the pancreaticobiliary limb is not adequate in length or integrity, after removal of the pancreatoduodenectomy specimen (Fig. 1b). Instead, the entire pancreatobiliary limb is resected down to the jejunojejunostomy, and removed with the specimen (Fig. 1c). A new jejunal limb is then brought up and used for the pancreatobiliary reconstruction (Fig. 1d). The roux limb should be of adequate length (≥ 40 cm) to diminish the possibility of reflux cholangitis. However, if significant small bowel has been resected during the operation, creating too long a limb can lead to short bowel syndrome. The reconstruction proceeds normally, once the biliopancreatic limb has been established. As long as the pancreatic duct can be identified, many surgeons would perform the pancreaticojejunal anastomosis by approximating the pancreatic parenchyma to the jejunal serosa using interrupted 3–0 silk sutures for the outer layer. The inner layer brings together pancreatic duct and jejunal mucosa using fine (5–0 or 6–0) interrupted absorbable sutures. Should the pancreatic duct not be identifiable, a small jejunotomy is made and a dunking anastomosis is often employed. In this case, an interrupted inner layer of absorbable sutures are placed approximating the cut edges of the pancreas and jejunum while an outer layer of interrupted non-absorbable sutures brings the jejunal serosa over the pancreas and approximating it to the pancreatic
capsule circumferentially. Typically, the biliary-jejunal anastomosis is performed using a slightly heavier (5–0 or 4–0) absorbable suture in an interrupted fashion. Should the patient’s prior gastrojejunostomy need revision or a new gastrojejunostomy be required, an antecolic reconstruction to the gastric pouch can be performed using a two layered technique in an end-to-side, functional end-to-end fashion, similar to the typical entero-enterostomy described above. In ordering the reconstruction, the surgeon should avoid placing all three anastomoses in anatomic succession—where the gastrojejunostomy precedes the hepaticojejunostomy and pancreaticojejunostomy. Such a reconstruction will allow the passage of partially digested foodstuffs from the stomach in close proximity to the hepaticojejunostomy (Fig. 2), leading to often recurrent and severe cholangitis or pancreatitis. Oftentimes, there will be severely dense adhesions around the gastric remnant making completion gastrectomy difficult. This can be a particularly hard problem when attempting dissection in patients who have had a complicated postoperative course after their initial bypass operation, either due to
Fig. 2 Depiction of reconstruction after pancreatoduodenectomy with completion gastrectomy in a patient who has undergone prior gastric bypass with gastrojejunostomy, pancreaticojejunostomy, and hepaticojejunostomy in series (not recommended). Enteric food stuffs are shown migrating towards the hepaticojejunostomy, leading to cholangitis (white arrow direction of enteral flow)
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gastrojejunostomy leak or postoperative abscess. In these patients, providing adequate drainage of the gastric remnant during the reconstruction is necessary. In this uncommon scenario, one option is to use the former biliopancreatic limb (Fig. 3) as a caudal, or draining gastrojejunostomy. However, as described above, in many cases, the remaining biliopancreatic limb is not of adequate length, and so a new draining gastrojejunostomy must be brought up, along with the creation of the pancreaticobiliary limb. As stated before, it is important that the surgeon take care not to leave too short a distal small bowel to cause severe malabsorption, nor place the gastrojejunostomy proximal to the biliopancreatic anastomoses, leading to cholangitis. Furthermore, a reconstruction utilizing a pancreaticogastrostomy is discouraged for two reasons. First, with a densely adhesed gastric remnant, it can be very difficult to mobilize the stomach adequately to anastomose the pancreatic remnant. Second, in patients who have undergone a bariatric procedure where the stomach remains in continuity (vertical banded gastroplasty, gastric sleeve, etc.) a pancreatic postoperative leak would preclude oral intake, whereas a separate pancreaticojejunostomy does not. Adjustable Gastric Banding and Vertical Banded Gastroplasty Fig. 3 Depiction of reconstruction after pancreatoduodenectomy in a patient who has undergone prior gastric bypass and whose gastric remnant cannot be resected. In this uncommon scenario, the remnant pancreatobiliary limb is used to drain the gastric remnant in this case. A separate pancreatobiliary limb is brought up for the reconstruction (white arrow direction of enteral flow)
The gastric banding operation involves the placement of an adjustable silicone band around the proximal stomach. The band is attached to a port placed in the subcutaneous tissue of the epigastrum, so that one can gradually adjust the diameter
Fig. 4 Depiction of anatomy a after gastric banding, and b after vertical band gastroplasty (white arrow direction of enteral flow)
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of the band, by instilling saline through the port, over time. The goal is to create a proximal gastric pouch, which can limit food intake. This operation is faster and carries less morbidity than Roux-en-Y gastric bypass. Nevertheless, weight loss is less pronounced than the gastric bypass operation (Fig. 4a,b). Popularized in the 1980s, vertical banded gastroplasty involves creating a transverse proximal gastric pouch of the upper portion of the lesser curvature of the stomach with a linear stapler. The pouch is only partially resected from the inferior stomach. Subsequently, a restrictive band is placed at the medial portion of the pouch, to control the outlet to the inferior stomach. Surgeons have largely abandoned this technique due to complications related to the band, such as high-grade stenosis of the distal outlet of the gastroplasty, as well as band erosion into the stomach. Nevertheless, there are still patients who may present with vertical banded gastroplasty (VBG) anatomy. Operative approach when performing pancreaticoduodenectomy The silicone band should be removed during their operation, as it can act as a significant nidus for postoperative infection. For
inflatable or adjustable gastric bands, the band should be deflated prior to beginning the operation. Dissection around the port should proceed with caution as intraperitoneal contents will often have scarred in closely below the device, and occasionally the band itself can migrate or erode into the left lobe of the liver. Often, adhesions near the esophageal hiatus from prior exposure will need to be taken down. Once entered into the peritoneal cavity, removing the band should be relatively simple, as it is deflated and unhooks easily. Exposure is of utmost importance in order to remove the band and adequately assess the tissue of the stomach. If, upon removal of the gastric band, gastric erosion is noted, resection or even near-total gastrectomy may be necessary. Careful assessment of the stomach should extend above and below the prior band site—as a missed erosion or injury can lead to leak or fistula, requiring a prompt return to the operating room. Near-total gastrectomy may also be indicated in the patient who has had vertical band gastrostomy. In these patients, the remnant stomach has a keyhole division in place and often proximal dilation due to gastric stenosis. If assessment of the stomach reveals no stenosis or erosion, classic pancreaticoduodenectomy with hemi-gastrectomy can still be employed and is the preferred approach.
Fig. 5 Depiction of anatomy of a gastric sleeve and b reconstruction using pylorus preserving technique (orange arrow depicts removal of gastric remnant)
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Sleeve Gastrectomy This operation is restrictive in nature only, with resection of the greater curvature of the stomach over a gastroesophageal bougie. The bougie is aligned along the lesser curvature of the stomach and used to size the remnant sleeve of stomach. The medial stomach is converted into a vertical tube by several firings of a laparoscopic stapler along the bougie. Weight loss
is achieved through this technique by limiting the gastric reservoir (Fig. 5a). Operative approach when performing pancreaticoduodenectomy The pancreatoduodenectomy is not affected by this prior operation, other than the scarring in the left upper quadrant.
Fig. 6 Depiction of a biliopancreatic diversion, b duodenal switch with sleeve gastrectomy and c reconstruction of a duodenal switch patient after pancreatoduodenectomy using the remnant pancreatobiliary limb, which is often long enough in these patients (white arrow direction of enteral flow)
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However, as the left and right gastroepiploic vessels have been ligated previously, these patients have already lost half of the blood supply to the stomach. Consideration should be given to preserving the right gastric artery along with the pylorus during pancreaticoduodenectomy (Fig. 5b) to prevent a low flow state to the stomach.
Biliopancreatic Diversion and Duodenal Switch Biliopancreatic diversion (BPD) was popular predominately in Europe, and it is similar to the gastric bypass operation, as it acts in both a restrictive and a malabsorptive capacity. The first step in the operation is creation of a proximal gastric pouch. The difference compared with the gastric bypass is the addition of a distal gastrectomy. A long roux limb is then used for a gastrojejunostomy, usually in front of both the transverse colon and stomach. In this operation, the jejunojejunostomy is typically further distal than in a gastric bypass, at approximately 100 cm from the ileocecal valve (Fig. 6a,b). Duodenal switch combines characteristics of the sleeve gastrectomy and gastric bypass/biliopancreatic diversion. It acts in both a restrictive and a malabsorptive capacity. The first step of the operation includes a sleeve gastrectomy of the greater curvature over a bougie, so that a long gastric pouch is created. The pyloric outlet is stapled off from the duodenum and the duodenal stump reinforced. A long roux limb is then anastomosed to the pylorus. Similar to BPD, the jejunojejunostomy is further distal than the gastric bypass operation, at approximately 100 cm proximal to the ileocecal valve. This operation also results in excellent weight loss for the patient, but patients are at higher risk for duodenal leak as well as extreme nutritional deficiencies and malabsorption due to the length of the roux limb. As a result, these operations have largely been abandoned in favor of the gastric bypass operation. Operative approach when performing pancreaticoduodenectomy The principles of biliopancreatic anastomoses in these operations are similar to those described above for Roux-en-Y gastric bypass. Due to the complexity of the operation however, these patients’ exploration and resection are even more likely to be impeded by dense adhesions. Whereas with Roux-en-Y gastric bypass the remnant pancreatobiliary limb is sometimes too short to be utilized in reconstruction, in these patients it is usually long enough to allow its use for both the hepaticojejunostomy and pancreaticojejunostomy (Fig. 6c). Patients who have had gastrojejunostomy for bariatric surgery of any kind, whether it be gastric bypass or biliopancreatic diversion, should have their gastrojejunostomy preserved whenever possible. The patient with duodenal switch may however require a revised or new gastrojejunostomy using
the alimentary jejunal limb, if the surgeon decides to perform a completion or near complete gastrectomy.
Conclusion In conclusion, the high rate of imaging in bariatric patients has led to an increase in the diagnosis of incidental pancreatic lesions. The pancreatic surgeon who undertakes pancreaticoduodenectomy in a postbariatric surgery patient must be cognizant of the potential pitfalls that accompany their prior operation. A diligent preoperative investigation of their anatomy as well as obtaining any prior operative notes is recommended. Depending on the prior operation and the hostility of the abdomen, the surgeon has several options for pancreaticobiliary resection and reconstruction.
Disclosures None
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