Surg Endosc DOI 10.1007/s00464-014-3944-5
and Other Interventional Techniques
DYNAMIC MANUSCRIPT
Foramen of Winslow hernia: a minimally invasive approach Cristina R. Harnsberger • Elisabeth C. McLemore • Ryan C. Broderick Hans F. Fuchs • Peter T. Yu • Martin Berducci • Catherine Beck • Moneer Almadani • Garth R. Jacobsen • Santiago Horgan
•
Received: 11 July 2014 / Accepted: 7 October 2014 Ó Springer Science+Business Media New York 2014
Abstract Hernias through the foramen of Winslow comprise 8 % of all internal hernias and the majority contain incarcerated bowel. Clinical signs are often nonspecific and delay in diagnosis associated with a mortality rate that approaches 50 %. Management is urgent surgical reduction with bowel decompression and resection of devitalized bowel. A foramen of Winslow hernia (FWH) has traditionally been managed via an exploratory laparotomy incision and the vast majority of cases describe an open approach. We describe a minimally invasive approach to the management of an incarcerated FWH requiring decompression and bowel resection. Keywords Hernia
Abdominal Bowel Colorectal Digestive
This work was presented at the SAGES 2014 Annual Meeting, April 2–5, 2014, Salt Lake City, Utah.
Electronic supplementary material The online version of this article (doi:10.1007/s00464-014-3944-5) contains supplementary material, which is available to authorized users. C. R. Harnsberger (&) E. C. McLemore R. C. Broderick H. F. Fuchs P. T. Yu M. Berducci C. Beck M. Almadani G. R. Jacobsen S. Horgan Department of Surgery, Center for the Future of Surgery, University of California, San Diego, San Diego, CA, USA e-mail: [email protected] H. F. Fuchs Department of Surgery, University of Cologne, Cologne, Germany
Introduction The foramen of Winslow, otherwise known as the epiploic or omental foramen, is the aperture between the greater and lesser peritoneal cavities. It is bordered anteriorly by the hepatoduodenal ligament, posteriorly by the inferior vena cava, superiorly by the caudate lobe of the liver, and inferiorly by the duodenum. The first reported finding of a hernia through the foramen of Winslow was published in 1834 by Bladin, and it has since been determined that FWHs comprise 8 % of all internal hernias [1, 2]. Small bowel is the most commonly involved viscus which accounts for approximately two thirds of the cases, followed by the cecum, ascending colon, and transverse colon, although other viscera have been implicated in case reports [1, 3]. Most reported cases are associated with intestinal obstruction, and a delay in treatment portends a mortality rate that approaches 50 % [1, 4, 5]. Multiple factors predispose one to development of a FWH. Risk factors include an enlarged foramen of Winslow, long small-bowel mesentery, elongated right hepatic lobe (such as a Riedel’s lobe), and redundancy of the ascending mesocolon causing increased mobility of the bowel [3–8]. A hernia through the foramen of Winslow is more prevalent in men and between age 20 and 60 years [1, 9]. Diagnosis of an FWH is commonly made at the time of surgery as clinical findings may be non-specific; however, plain film and cross-sectional imaging with computed tomography (CT) can improve the ability to diagnose a suspected FWH pre-operatively [3, 10]. Plain film findings suggestive of a hernia through the foramen of Winslow include a collection of gas in the lesser sac which displaces the stomach anteriorly and laterally, failure to visualize the cecum in its normal position, and displacement of the stomach and duodenum to the left [4, 6]. Suggestive CT
123
Surg Endosc Table 1 Published reports of foramen of Winslow hernias managed laparoscopically First Author
Publication (year)
Herniated viscera
Bowel resection
Needle decompression of herniated viscera required
Webb, L[13]
2009
Colon
No
No
Clough, AD[14] Van Daele, E[15]
2011
Colon
No
No
2011
Colon
No
No
Lin, WC[16]
2013
Ileum
No
No
Numata, K[17]
2013
Gallbladder
NA
Yes
Ryan, J[18]
2014
Colon
Appendix
No
values were significant for a mildly elevated lactate. Abdominal plain films demonstrated a dilated loop of colon superior to the stomach (Fig. 1). CT scan demonstrated an internal hernia with the cecum in the right upper quadrant, and the ascending colon and terminal ileum passing posterior to the liver pedicle with resulting compression of the common bile duct and portal vein (Fig. 2). The patient underwent an urgent exploratory laparoscopy. Inspection confirmed that the cecum and terminal ileum had herniated through the foramen of Winslow into the lesser peritoneal cavity. The herniated bowel was sufficiently dilated such that attempted laparoscopic manual reduction was not successful, and thus, needle decompression was performed. A large foramen of Winslow was present, and the defect was obliterated with mobilized omentum to prevent recurrence. In addition, a right hemicolectomy was performed as the cecum and ascending colon appeared ischemic despite reduction. Surgical technique
findings are air-fluid levels between the liver hilum and the inferior vena cava which taper toward the foramen, anterolateral displacement of the stomach, absence of the ascending colon in the right paracolic gutter with displacement superiorly, and presence of mesentery between the portal vein and inferior vena cava [3, 6, 11]. Proper management of an FWH, as with any incarcerated internal hernia, is urgent surgical reduction of the herniated contents with resection bowel only in instances of bowel ischemia or non-viability. The overwhelming majority of cases are managed with a laparotomy. In instances where manual reduction of herniated contents was not possible due to bowel dilation, needle decompression of the involved bowel is described [6, 12]. There are a few case reports in which a minimally invasive approach was utilized [13–18], none of which required bowel decompression (Table 1). Additionally, none of the existing case reports managed laparoscopically required bowel resection, as non-ischemic, viable bowel was able to be reduced in all instances. The technique for laparoscopic management of an incarcerated foramen of Winslow hernia (FWH) that requires bowel decompression and resection is described in this manuscript and accompanying videos.
Methods Patient presentation A 57-year-old female with no prior surgical history, presented to the emergency department with 1 day of worsening, diffuse abdominal pain. She was found to have a distended abdomen and signs of peritonitis. Laboratory
123
In a laparoscopic approach to an FWH, the patient is placed supine in a modified lithotomy position and in reverse Trendelenburg. An optical trocar or Hasson technique for peritoneal entry is preferred to Veress needle access in this clinical setting as dilated loops of bowel are expected in the left upper quadrant. A 12-mm optical port is placed in the supra-umbilical position using the umbilical stalk cut down technique, and two five-millimeter working ports are placed in the left lateral abdominal and suprapubic regions. An additional subxiphoid 5-mm incision is used for liver retraction. The first step is identification of the patient’s anatomy, as the diagnosis at the time of laparoscopy may not be clear. Next, attempted reduction of the herniated viscera is performed using atraumatic bowel graspers to apply gentle traction; excessive force can lead to pressure and tension on the structures of the porta hepatis or result in bowel injury (see Electronic supplementary material 1). If reduction cannot be achieved with traction alone, bowel decompression can be performed as is demonstrated in this case. A 16-gauge angiocatheter is introduced through the abdominal wall and into the dilated bowel, with aspiration of contents until bowel decompression is accomplished. Reduction of herniated viscera is then achieved with manual traction. A looped laparoscopic suture is then placed around the enterotomy site to control spillage of intraluminal contents during the remainder of the case (see Electronic supplementary material 2). There are no current guidelines for foramen of Winslow closure in the case of a hernia. However, should the surgeon desire closure, as may be the case in a large foramen of Winslow, obliteration of the hernia defect can be
Surg Endosc Fig. 1 Supine and upright abdominal plain film images
Fig. 2 Axial and coronal ct scan images
Table 2 Steps in laparoscopic management of a foramen of Winslow hernia
Results
- Define anatomy - Attempt manual reduction of herniated viscera
Postoperatively, the patient was started on a clear liquid diet immediately, with advancement as tolerated. Prompt return of bowel function was observed in this case and the patient was discharged on post-operative day four. Pathologic evaluation of the resected bowel confirmed ischemia with viable margins and no evidence of neoplasia. There were no short or long-term complications and the patient is doing well 21 months postoperatively.
- Decompress bowel if unable to reduce - Obliterate the hernia defect - Bowel resection for ischemia or to prevent recurrence
performed. One option is to use harvested omentum from the transverse colon with suture fixation as necessary to the anterior stomach. After reduction of the herniated contents, non-viable bowel is resected and a primary anastomosis constructed (unless gross contamination, septic shock, or severe malnutrition is also present). If the bowel lacks anatomical fixation and there is reasonable concern for recurrent hernia, a preventative segmental bowel resection can be performed. Specimen extraction is performed through the periumbilical extraction incision with utilization of a wound protector (see Electronic supplementary material 3). The steps of laparoscopic management of an FWH are summarized in Table 2.
Discussion For surgeons experienced in laparoscopic management of gastrointestinal disease processes, a laparoscopic approach in a case of an internal hernia or suspected FWH offers several advantages including further diagnostic evaluation and enhanced recovery after surgical intervention. Additionally, management using a minimally invasive approach decreases the estimated risk of some complications. Using the American College of Surgeons National Surgical Quality Improvement surgical risk calculator, the risk of
123
Surg Endosc
surgical site infection for the aforementioned patient using the laparoscopic technique is 5 % and the risk of serious complication is 8 %; however, if an open approach is utilized these risks increase to 10 and 13 %, respectively [19]. We demonstrate that a minimally invasive approach is safe and feasible, even when bowel decompression and segmental bowel resection are necessary. In cases where FOWs are managed laparoscopically, the patient is expected to experience the general benefits of a minimally invasive approach such as decreased pain, shorter length of stay, quicker recovery, and return to activities of daily living. When a laparoscopic approach is employed, there are instances when conversion to open surgery is appropriate, such as inadequate visualization, inability to adequately define the patient’s anatomy, bowel perforation with gross contamination, and failure to progress laparoscopically.
Conclusion Using current imaging techniques, an FWH may be suspected pre-operatively, which gives the surgeon an opportunity to consider a laparoscopic approach. Management of an incarcerated viscus within an FWH is feasible and safe to perform with a minimally invasive technique, even in instances where bowel decompression or segmental bowel resection are necessary. Disclosures Drs. Harnsberger, McLemore, Broderick, Fuchs, Yu, Berducci, Beck, Almadani, Jacobsen, and Horgan have no conflicts of interest of financial ties to disclose.
References 1. Osvaldt AB, Mossmann DF, Bersch VP, Rohde L (2008) Intestinal obstruction caused by a foramen of Winslow hernia. Am J Surg 196(2):242–244 2. Hansman GH, Morton SA (1939) Intraabdominal hernias. Arch Surg 39:973–986 3. Martin L, Merkle E, Thompson W (2006) Review of internal hernias: radiographic and clinical findings. AJR Am J Roentgenol 186(3):703–717
123
4. Erskine JM (1967) Hernia through the foramen of Winslow. Surg Gynaecol Obstet 125(1093–109):3 5. Smith RLG, Mansfield S, Wood T, Lambrinadides AL (2012) Extensive herniation and necrosis of the small and large bowel through the foramen of Winslow. Am Surg 78:E429–E431 6. Da Costa G, Ng B, Kociumbas I, Wong S (2007) Herniation of caecum through the foramen of Winslow. Australas Radiol 51:B152–B154 7. Puig CA, Lillegard JB, Fisher JE, Schiller HJ (2013) Hernia of cecum and ascending colon through the foramen of Winslow. Int J Surg Case Rep 4(10):879–881 8. Huang W, Fu C (2012) Images in clinical medicine. Hernia through the foramen of Winslow. N Engl J Med 367(5):e7 9. Tran TL, Pitt PC (1989) Hernia through the foramen of Winslow. A report of two cases with emphasis on plain film interpretation. Clin Radiol 40:264–266 10. Takeyama N, Gokan T, Ohgiya Y, Satoh S, Hashizume T, Hataya K, Kushiro H, Nakanishi M, Kusano M, Munechika H (2005) CT of internal hernias. Radiographics 25:997–1015 11. Wojtasek DA, Codner MA, Nowak EJ (1991) CT diagnosis of cecal herniation through the foramen of Winslow. Abdom Imaging 16:77–79 12. King P, Smart R (1979) Caecal herniation through the foramen of Winslow. Aust N Z J Surg 5:582–584 13. Webb L, Riordan W (2009) Internal herniation of the cecum through the foramen of Winslow. Am Surg 75(12):1252–1253 14. Clough AD, Smith GS, Leibman S (2011) Laparoscopic reduction of an internal hernia of transverse colon through the foramen of Winslow. Surg Laparosc Endosc Percutan Tech 21(4):e190– e191 15. Van Daele E, Poortmans M, Vierendeels T, Potvlieghe P, Rots W (2011) Herniation through the foramen of Winslow: a laparoscopic approach. Hernia 15(4):447–449 16. Lin WC, Lin CH, Lo YP, Liao YH (2013) Rapid pre-operative diagnosis of ileal hernia through the foramen of Winslow with multi-detector computed tomography, enabling successful laparoscopic reduction. S Afr J Surg 51(1):35–37 17. Numata K, Kunishi Y, Kurakami Y, Tsuchida K, Yoshida T, Osaragi T, Yoneyama K, Kasajara A, Yamamoto Y, Yukawa N, Rino Y, Masuda M (2013) Gallbladder herniation into the lesser sac through the foramen of Winslow: report of a case. Surg Today 43(10):1194–1198 18. Ryan J, Jin S, Frank J, Jacobs R (2014) Internal herniation of the caecum through the foramen of Winslow. ANZ J Surg 84(1–2):95–96 19. American College of Surgeons, National surgical quality improvement project: surgical risk calculator. www.riskcalcu lator.facs.org.
and Other Interventional Techniques
DYNAMIC MANUSCRIPT
Foramen of Winslow hernia: a minimally invasive approach Cristina R. Harnsberger • Elisabeth C. McLemore • Ryan C. Broderick Hans F. Fuchs • Peter T. Yu • Martin Berducci • Catherine Beck • Moneer Almadani • Garth R. Jacobsen • Santiago Horgan
•
Received: 11 July 2014 / Accepted: 7 October 2014 Ó Springer Science+Business Media New York 2014
Abstract Hernias through the foramen of Winslow comprise 8 % of all internal hernias and the majority contain incarcerated bowel. Clinical signs are often nonspecific and delay in diagnosis associated with a mortality rate that approaches 50 %. Management is urgent surgical reduction with bowel decompression and resection of devitalized bowel. A foramen of Winslow hernia (FWH) has traditionally been managed via an exploratory laparotomy incision and the vast majority of cases describe an open approach. We describe a minimally invasive approach to the management of an incarcerated FWH requiring decompression and bowel resection. Keywords Hernia
Abdominal Bowel Colorectal Digestive
This work was presented at the SAGES 2014 Annual Meeting, April 2–5, 2014, Salt Lake City, Utah.
Electronic supplementary material The online version of this article (doi:10.1007/s00464-014-3944-5) contains supplementary material, which is available to authorized users. C. R. Harnsberger (&) E. C. McLemore R. C. Broderick H. F. Fuchs P. T. Yu M. Berducci C. Beck M. Almadani G. R. Jacobsen S. Horgan Department of Surgery, Center for the Future of Surgery, University of California, San Diego, San Diego, CA, USA e-mail: [email protected] H. F. Fuchs Department of Surgery, University of Cologne, Cologne, Germany
Introduction The foramen of Winslow, otherwise known as the epiploic or omental foramen, is the aperture between the greater and lesser peritoneal cavities. It is bordered anteriorly by the hepatoduodenal ligament, posteriorly by the inferior vena cava, superiorly by the caudate lobe of the liver, and inferiorly by the duodenum. The first reported finding of a hernia through the foramen of Winslow was published in 1834 by Bladin, and it has since been determined that FWHs comprise 8 % of all internal hernias [1, 2]. Small bowel is the most commonly involved viscus which accounts for approximately two thirds of the cases, followed by the cecum, ascending colon, and transverse colon, although other viscera have been implicated in case reports [1, 3]. Most reported cases are associated with intestinal obstruction, and a delay in treatment portends a mortality rate that approaches 50 % [1, 4, 5]. Multiple factors predispose one to development of a FWH. Risk factors include an enlarged foramen of Winslow, long small-bowel mesentery, elongated right hepatic lobe (such as a Riedel’s lobe), and redundancy of the ascending mesocolon causing increased mobility of the bowel [3–8]. A hernia through the foramen of Winslow is more prevalent in men and between age 20 and 60 years [1, 9]. Diagnosis of an FWH is commonly made at the time of surgery as clinical findings may be non-specific; however, plain film and cross-sectional imaging with computed tomography (CT) can improve the ability to diagnose a suspected FWH pre-operatively [3, 10]. Plain film findings suggestive of a hernia through the foramen of Winslow include a collection of gas in the lesser sac which displaces the stomach anteriorly and laterally, failure to visualize the cecum in its normal position, and displacement of the stomach and duodenum to the left [4, 6]. Suggestive CT
123
Surg Endosc Table 1 Published reports of foramen of Winslow hernias managed laparoscopically First Author
Publication (year)
Herniated viscera
Bowel resection
Needle decompression of herniated viscera required
Webb, L[13]
2009
Colon
No
No
Clough, AD[14] Van Daele, E[15]
2011
Colon
No
No
2011
Colon
No
No
Lin, WC[16]
2013
Ileum
No
No
Numata, K[17]
2013
Gallbladder
NA
Yes
Ryan, J[18]
2014
Colon
Appendix
No
values were significant for a mildly elevated lactate. Abdominal plain films demonstrated a dilated loop of colon superior to the stomach (Fig. 1). CT scan demonstrated an internal hernia with the cecum in the right upper quadrant, and the ascending colon and terminal ileum passing posterior to the liver pedicle with resulting compression of the common bile duct and portal vein (Fig. 2). The patient underwent an urgent exploratory laparoscopy. Inspection confirmed that the cecum and terminal ileum had herniated through the foramen of Winslow into the lesser peritoneal cavity. The herniated bowel was sufficiently dilated such that attempted laparoscopic manual reduction was not successful, and thus, needle decompression was performed. A large foramen of Winslow was present, and the defect was obliterated with mobilized omentum to prevent recurrence. In addition, a right hemicolectomy was performed as the cecum and ascending colon appeared ischemic despite reduction. Surgical technique
findings are air-fluid levels between the liver hilum and the inferior vena cava which taper toward the foramen, anterolateral displacement of the stomach, absence of the ascending colon in the right paracolic gutter with displacement superiorly, and presence of mesentery between the portal vein and inferior vena cava [3, 6, 11]. Proper management of an FWH, as with any incarcerated internal hernia, is urgent surgical reduction of the herniated contents with resection bowel only in instances of bowel ischemia or non-viability. The overwhelming majority of cases are managed with a laparotomy. In instances where manual reduction of herniated contents was not possible due to bowel dilation, needle decompression of the involved bowel is described [6, 12]. There are a few case reports in which a minimally invasive approach was utilized [13–18], none of which required bowel decompression (Table 1). Additionally, none of the existing case reports managed laparoscopically required bowel resection, as non-ischemic, viable bowel was able to be reduced in all instances. The technique for laparoscopic management of an incarcerated foramen of Winslow hernia (FWH) that requires bowel decompression and resection is described in this manuscript and accompanying videos.
Methods Patient presentation A 57-year-old female with no prior surgical history, presented to the emergency department with 1 day of worsening, diffuse abdominal pain. She was found to have a distended abdomen and signs of peritonitis. Laboratory
123
In a laparoscopic approach to an FWH, the patient is placed supine in a modified lithotomy position and in reverse Trendelenburg. An optical trocar or Hasson technique for peritoneal entry is preferred to Veress needle access in this clinical setting as dilated loops of bowel are expected in the left upper quadrant. A 12-mm optical port is placed in the supra-umbilical position using the umbilical stalk cut down technique, and two five-millimeter working ports are placed in the left lateral abdominal and suprapubic regions. An additional subxiphoid 5-mm incision is used for liver retraction. The first step is identification of the patient’s anatomy, as the diagnosis at the time of laparoscopy may not be clear. Next, attempted reduction of the herniated viscera is performed using atraumatic bowel graspers to apply gentle traction; excessive force can lead to pressure and tension on the structures of the porta hepatis or result in bowel injury (see Electronic supplementary material 1). If reduction cannot be achieved with traction alone, bowel decompression can be performed as is demonstrated in this case. A 16-gauge angiocatheter is introduced through the abdominal wall and into the dilated bowel, with aspiration of contents until bowel decompression is accomplished. Reduction of herniated viscera is then achieved with manual traction. A looped laparoscopic suture is then placed around the enterotomy site to control spillage of intraluminal contents during the remainder of the case (see Electronic supplementary material 2). There are no current guidelines for foramen of Winslow closure in the case of a hernia. However, should the surgeon desire closure, as may be the case in a large foramen of Winslow, obliteration of the hernia defect can be
Surg Endosc Fig. 1 Supine and upright abdominal plain film images
Fig. 2 Axial and coronal ct scan images
Table 2 Steps in laparoscopic management of a foramen of Winslow hernia
Results
- Define anatomy - Attempt manual reduction of herniated viscera
Postoperatively, the patient was started on a clear liquid diet immediately, with advancement as tolerated. Prompt return of bowel function was observed in this case and the patient was discharged on post-operative day four. Pathologic evaluation of the resected bowel confirmed ischemia with viable margins and no evidence of neoplasia. There were no short or long-term complications and the patient is doing well 21 months postoperatively.
- Decompress bowel if unable to reduce - Obliterate the hernia defect - Bowel resection for ischemia or to prevent recurrence
performed. One option is to use harvested omentum from the transverse colon with suture fixation as necessary to the anterior stomach. After reduction of the herniated contents, non-viable bowel is resected and a primary anastomosis constructed (unless gross contamination, septic shock, or severe malnutrition is also present). If the bowel lacks anatomical fixation and there is reasonable concern for recurrent hernia, a preventative segmental bowel resection can be performed. Specimen extraction is performed through the periumbilical extraction incision with utilization of a wound protector (see Electronic supplementary material 3). The steps of laparoscopic management of an FWH are summarized in Table 2.
Discussion For surgeons experienced in laparoscopic management of gastrointestinal disease processes, a laparoscopic approach in a case of an internal hernia or suspected FWH offers several advantages including further diagnostic evaluation and enhanced recovery after surgical intervention. Additionally, management using a minimally invasive approach decreases the estimated risk of some complications. Using the American College of Surgeons National Surgical Quality Improvement surgical risk calculator, the risk of
123
Surg Endosc
surgical site infection for the aforementioned patient using the laparoscopic technique is 5 % and the risk of serious complication is 8 %; however, if an open approach is utilized these risks increase to 10 and 13 %, respectively [19]. We demonstrate that a minimally invasive approach is safe and feasible, even when bowel decompression and segmental bowel resection are necessary. In cases where FOWs are managed laparoscopically, the patient is expected to experience the general benefits of a minimally invasive approach such as decreased pain, shorter length of stay, quicker recovery, and return to activities of daily living. When a laparoscopic approach is employed, there are instances when conversion to open surgery is appropriate, such as inadequate visualization, inability to adequately define the patient’s anatomy, bowel perforation with gross contamination, and failure to progress laparoscopically.
Conclusion Using current imaging techniques, an FWH may be suspected pre-operatively, which gives the surgeon an opportunity to consider a laparoscopic approach. Management of an incarcerated viscus within an FWH is feasible and safe to perform with a minimally invasive technique, even in instances where bowel decompression or segmental bowel resection are necessary. Disclosures Drs. Harnsberger, McLemore, Broderick, Fuchs, Yu, Berducci, Beck, Almadani, Jacobsen, and Horgan have no conflicts of interest of financial ties to disclose.
References 1. Osvaldt AB, Mossmann DF, Bersch VP, Rohde L (2008) Intestinal obstruction caused by a foramen of Winslow hernia. Am J Surg 196(2):242–244 2. Hansman GH, Morton SA (1939) Intraabdominal hernias. Arch Surg 39:973–986 3. Martin L, Merkle E, Thompson W (2006) Review of internal hernias: radiographic and clinical findings. AJR Am J Roentgenol 186(3):703–717
123
4. Erskine JM (1967) Hernia through the foramen of Winslow. Surg Gynaecol Obstet 125(1093–109):3 5. Smith RLG, Mansfield S, Wood T, Lambrinadides AL (2012) Extensive herniation and necrosis of the small and large bowel through the foramen of Winslow. Am Surg 78:E429–E431 6. Da Costa G, Ng B, Kociumbas I, Wong S (2007) Herniation of caecum through the foramen of Winslow. Australas Radiol 51:B152–B154 7. Puig CA, Lillegard JB, Fisher JE, Schiller HJ (2013) Hernia of cecum and ascending colon through the foramen of Winslow. Int J Surg Case Rep 4(10):879–881 8. Huang W, Fu C (2012) Images in clinical medicine. Hernia through the foramen of Winslow. N Engl J Med 367(5):e7 9. Tran TL, Pitt PC (1989) Hernia through the foramen of Winslow. A report of two cases with emphasis on plain film interpretation. Clin Radiol 40:264–266 10. Takeyama N, Gokan T, Ohgiya Y, Satoh S, Hashizume T, Hataya K, Kushiro H, Nakanishi M, Kusano M, Munechika H (2005) CT of internal hernias. Radiographics 25:997–1015 11. Wojtasek DA, Codner MA, Nowak EJ (1991) CT diagnosis of cecal herniation through the foramen of Winslow. Abdom Imaging 16:77–79 12. King P, Smart R (1979) Caecal herniation through the foramen of Winslow. Aust N Z J Surg 5:582–584 13. Webb L, Riordan W (2009) Internal herniation of the cecum through the foramen of Winslow. Am Surg 75(12):1252–1253 14. Clough AD, Smith GS, Leibman S (2011) Laparoscopic reduction of an internal hernia of transverse colon through the foramen of Winslow. Surg Laparosc Endosc Percutan Tech 21(4):e190– e191 15. Van Daele E, Poortmans M, Vierendeels T, Potvlieghe P, Rots W (2011) Herniation through the foramen of Winslow: a laparoscopic approach. Hernia 15(4):447–449 16. Lin WC, Lin CH, Lo YP, Liao YH (2013) Rapid pre-operative diagnosis of ileal hernia through the foramen of Winslow with multi-detector computed tomography, enabling successful laparoscopic reduction. S Afr J Surg 51(1):35–37 17. Numata K, Kunishi Y, Kurakami Y, Tsuchida K, Yoshida T, Osaragi T, Yoneyama K, Kasajara A, Yamamoto Y, Yukawa N, Rino Y, Masuda M (2013) Gallbladder herniation into the lesser sac through the foramen of Winslow: report of a case. Surg Today 43(10):1194–1198 18. Ryan J, Jin S, Frank J, Jacobs R (2014) Internal herniation of the caecum through the foramen of Winslow. ANZ J Surg 84(1–2):95–96 19. American College of Surgeons, National surgical quality improvement project: surgical risk calculator. www.riskcalcu lator.facs.org.
