1. Dr Chan Wai Hei, Arthur Queen Elizabth Hospital
Parastomal hernia
Dr Chan Wai Hei, Arthur
Queen Elizabth Hospital

2. Overview Background Classification Risk factors
Clinical presentation & Complications requiring surgical intervention
Management
Prevention

3. Definition
A parastomal hernia (PSH) is a type of incisional hernia that occurs at the site of stoma or immediately adjacent to the stoma
The most common late complication of a permanent stoma

4. Incidence Variable incidence reported in literature
Incidence increases with time
Most occur within 2 years of stoma formation
Some believe that it is an inevitable consequence of stoma formation

5. Incidence
[Pilgrim CH, McIntyre R, Bailey M. Prospective audit of parastomal hernia: prevalence and associated comorbidities. Dis Colon Rectum 2010;53:71-6]

6. Incidence Literature review by Carne et al.
% in end ileostomies
0-6.2% in loop ileostomies
% in end colostomies
0-30.8% in loop colostomies
[Carne PW, Robertson GM, Frizelle FA. Parastomal hernia. Br J Surg 2003;90:784-93]

7. Classification
Traditional
Radiological

8. Classification - Traditional
4 subtypes
1) Subcutaneous
most common type
the herniation enters into the subcutaneous fat alongside the stoma
2) Interstitial
the herniation extrudes alongside the bowel for stoma, then burrows into one of the intermuscular planes
3) Peristomal
the stomal bowel is prolapsed and loops of bowel and/or omentum enter the hernia space produced between the layers of prolapsed bowel
4) Intrastomal
enters the plane between the merging and the everted part of bowel
usually occurs in the spout type of stoma – e.g. ileostomy
[Devlin HB. Peristomal hernia. In: Operative Surgery Volume 1: Alimentary Tract and Abdominal Wall, 4th ed, Dudley H (Ed), Butterworths, London p.441.]

9. Classification - Radiological
type Ia
type Ib
type II
type III
[Moreno-matias J, Serra-aracil X, Darnell-martin A et-al. The prevalence of parastomal hernia after formation of an end colostomy. A new clinico-radiological classification. Colorectal Dis. 2009;11 (2): 173-7]

10. Risk factors
Patient-related
Surgery-related

11. Patient-related risk factors
Age
Obesity (>30kg/m2) and waist circumference (>100cm)
Poor nutritional status
Increased intraabdominal pressure (COAD, constipation, BPH, ascites, etc)
Connective tissue disorders
Immunosuppressive drugs (e.g. corticosteroids)
Other disease predispose to wound infection (e.g. DM)
Other underlying diseases (e.g. IBD, malignancy)

12. Surgery-related risk factors
Emergency construction of stoma
Stoma lateral to rectus muscle
Diameter of trephine
defect >3cm was found to be associated with a higher incidence of herniation, independent of stoma type
currently few data to base advice about the appropriate size of abd wall opening
suggestions of not more than 2.5cm had been made
smallest opening that allows the creation of a viable stoma without ischaemia appears to be the best guide
Closure of lateral space
Stoma fixation to fascia
Intraperitoneal or extraperitoneal approach

13. Clinical presentation
Vary from asymptomatic to life-threatening strangulation
Typically – bulge at the site of or adjacent to the stoma, with or without pain
Mild abd discomfort, intermittent colic, distention, nausea & vomiting, diarrhoea, constipation and a reducible hernia
Physical examination – on lying down and standing with valsalva
Digital examination enables the fascial aperture and parastomal tissues to be assessed

14. Complications requiring surgery
Literature reported a range of 11%-70%
Local data: ~32% require surgical intervention
Urgent surgery for strangulation of an irreducible hernia
Following signs & symptoms can be repaired electively
increasing size
intermitted bowel obstructions
chronic abdominal pain related to PSH
ill-fitting appliance and leakage
peristomal skin breakdown
other stoma complications

15. Management Conservative Surgery Prevention Closure of stoma
Direct fascial repair
Relocation
Mesh repair
Different location
Lap vs open
Laparoscopic techniques
Prevention

16. Direct fascial repair
Reduce size of hernia defect by reapproximating the fascial edges of trephine with sutures
Advantage
simple technique
avoids laparotomy
low complication rate in elective operation
may have a role when there is a strong desire to avoid mesh or more major surgery
Disadvantage
excessive tension and subsequent failure in large fascial defect
high recurrence rate – reported in various literature to be %

17. Relocation
This approach avoided because the new stoma at new site is associated with the same high risk of hernia formation
Some authors reported a lower recurrence rate after relocation to other side of abdominal wall than relocation on the same side of abdomen
Advantage
useful if the current stoma position unsatisfactory
can be done with or without laparotomy
lower recurrence rate than direct fascial repair
Disadvantage
local recurrence rate reported in literature ~36.3% (range up to 76.2%)
not feasible if patient has multiple previous scars
risk of incisional hernia at the site of the original stoma or midline wound
more risk of morbidity if require laparotomy
[Carne PW, Robertson GM, Frizelle FA. Parastomal hernia. Br J Surg 2003;90:784-93]

18. Mesh repair
Overall recurrence rates after mesh repair vary between % (depending on technique and placement of mesh)
Overall mesh infection rate 2.4%
Risk of mesh infection did not differ between mesh techniques
[HanssonBM, Slater NJ, Schouten van der Velden AP, Groenewoud HM, Buyne OR, de Hingh IH, Beichrodt RP (2012) Surgical techniques for parastomal hernia repair: a systematic review of literature. Ann Surg 255(4): ]

19. Different anatomical locations of mesh
[Israelsson LA. Parastomal hernias. Surg Clin North Am. 2008;88: ]

20. Onlay technique First described by Rosin and Bonardi in 1977
Mesh placed subcutaneously and fixed onto the anterior rectus aponeurosis
Prefascial plane was entered through a lateral parastomal incision
After reduction of hernia sac, the fascial opening was narrowed with sutures and mesh was placed to reinforce the suture repair
Advantage:
more straight forward surgical technique involving a mesh
avoids intra-abdominal dissection
Disadvantage
associated with higher risk of contamination & sepsis than sublay technique
extensive dissection of subcutaneous tissue
predisposes to haematoma / seroma formation
undermining is a risk for ischaemic injury to skin => impair wound healing
intraabdominal pressure may lead to detachment of mesh resulting in recurrence

21. Onlay technique Recurrence rate ~17%
Mesh infection rate 2.6% (requiring removal of mesh)
[HanssonBM, Slater NJ, Schouten van der Velden AP, Groenewoud HM, Buyne OR, de Hingh IH, Beichrodt RP (2012) Surgical techniques for parastomal hernia repair: a systematic review of literature. Ann Surg 255(4): ]

22. Sublay technique
Mesh placed between rectus muscle and posterior sheath
Fewer studies evaluating this method of mesh placement
Small series with relatively short follow up (most <12mo)
Overall recurrence rate 6.9%
Advantage
intraabdominal pressure does not dislocate the mesh from repair
no direct contact with bowel
Disadvantage
more technically challenging than onlay technique

23. Inlay tecnique
Mesh cut to size of abdominal wall defect, placed within fascial defect and sutured to fascial edges
Abandoned because of high failure rates

24. Intraperitoneal onlay position (IPOM)
Mesh placed intraabdominally on the peritoneum
2 techniques – keyhole or Sugarbaker
Sugarbaker technique
Keyhole technique
[HanssonBM, Slater NJ, Schouten van der Velden AP, Groenewoud HM, Buyne OR, de Hingh IH, Beichrodt RP (2012) Surgical techniques for parastomal hernia repair: a systematic review of literature. Ann Surg 255(4): ]

25. Sugarbaker technique Sugarbaker first described his technique in 1980
trephine opening is covered with an intraperitoneally placed mesh via a laparotomy and sutured to fascial edge
bowel is lateralized passing from hernia sac between the abdominal wall and mesh into the peritoneal cavity
later modified to provide at least 5cm overlap of mesh and adjacent fascia
Advantage
generous mesh overlap
flap valve effect created able to withstand increased intraabdominal pressure
Disadvantage
mesh related complications
dense adhesions causing intestinal obstruction requiring laparotomy
bowel erosion & fistula formation
Main application of these techniques is in laparoscopic repair

26. IPOM
[HanssonBM, Slater NJ, Schouten van der Velden AP, Groenewoud HM, Buyne OR, de Hingh IH, Beichrodt RP (2012) Surgical techniques for parastomal hernia repair: a systematic review of literature. Ann Surg 255(4): ]

27. Laparscopic techniques
Key-hole vs modified sugarbaker vs sandwich technique
Potential advantages
minimal additional injury to abdominal wall which is already at risk of herniation
better view of defect allowing more precise repair and reinforcement with a mesh
concomitant incisional hernia repair
faster postop recovery and decreased postop pain
Sandwich technique
two mesh technique (combination of Keyhole and Sugarbaker)
keyhole mesh wrapped around stoma loop covering the fascial gap with the intact part
incised part of mesh were medially closed
further mesh with nonabsorbable stay sutures covered the first mesh and the whole abdominal wall
stoma loop placed between both meshes providing the desired lateralization of at least 5cm
[Berger D, Bientzle M. Polyvinylidene fluoride: a suitable mesh material for laparoscopic incisional and parastomal hernia repair. A prospective, observational study with 344 patients. Hernia. 2009;13: ]

28. Laparoscopic techniques
Key-hole vs modified sugarbaker vs sandwich technique
Recurrence rate:
Keyhole 34.6%
Sugarbaker 11.6%
Sandwich 2.1%
Conversion rate 3.6%
reasons: multiple dense adhesions, bowel injury, inaccessible abdomen
Mesh infection rate 2.7%
Wound infection 3.3%
Other complication rates 12.7%
bowel injury 4.1% (15/363)
5 repaired laparoscopically (1 hernia repair was postponed)
6 converted to open
4 were undetected (small bowel injury) during operation (3 required reoperation, 1 resulted in multiorgan failure and death)
-within the laparoscopic techniques, Sugarbaker technique resulted in a significantly lower recurrence rate compared with keyhole technique
-one explanation is that
-with Keyhole technique, it is difficult to estimate the size of the hole to ‘snugly’ accommodate the bowel
-also, shrinkage of mesh may result in enlargement of central hole
-use of sandwich technique was reported only in one study by Berger
-combination of the two techniques
-used polyvinylidenefluoride meshes (PVDF)
-median follow up of 20 months (range 6-48 months)
-1/47 (2.1%) patients had a recurrent hernia

29. Lap vs Open techniques
Mesh techniques did not differ significantly in terms of recurrence
Overall laparoscopic repair had no advantage over open repair
[HanssonBM, Slater NJ, Schouten van der Velden AP, Groenewoud HM, Buyne OR, de Hingh IH, Beichrodt RP (2012) Surgical techniques for parastomal hernia repair: a systematic review of literature. Ann Surg 255(4): ]

30. Prevention
High incidence of parastomal hernia together with unsatisfactory results of its repair and morbidity associated with operation lead to emphasis on prevention
Prevention strategies
surgical techniques
prophylactic mesh insertion

31. Surgical techniques in prevention
Through or lateral rectus abdominis
only retrospective studies found lower rate of PSH with stomas formed through the rectus muscle
nonetheless probably wise to bring out stoma throught rectus abdominis ms as this is not associated with any disadvantage
Fascial fixation
Closure of lateral space
Trephine size
Extraperitoneal route for stoma construction
-stoma site (throught or lateral to rectus abdominis), trephine size and fascial fixation have not been shown to influence the formation of parastomal hernia
-Carne et al reported that no technical strategies related to construction of stoma were shown to prevent herniation

32. Extraperitoneal route for permanent colostomy
Few studies had shown that extraperitoneal approach can achieve lower risk of herniation than transperitoneal route
Potential disadvantage
longer operative time
may need mobilization of splenic flexure for extra length
Goligher first published the formation of extraperitoneal colostomy in 1958
extraperitoneal route provides an oblique passage of bowel and eliminate the lateral peritoneal space without using suture
attempt to reduce risk of postop small bowel obstruction due to internal herniation into lateral peritoneal space and reduce parastomal hernia
Since then, subsequent studies have been published with inconsistent results
Only 2 retrospective studies found extraperitoneal colostomy construction was associated with a lower rate of parastomal herniation than intraperitoneal route
most studies were observational retrospective studies with small numbers of patients undergoing extraperitoneal colostomy and follow up period was not mentioned
Studies of highter quality, including RCTS with larger no. of patients are needed

33. Prophylactic mesh insertion
Bayer and colleagues first described mesh insertion at the time of primary stoma formation in 1986
Since then many observational studies confirmed the safety and effectiveness of prophylactic mesh insertion with low morbidity
Three RCTs ( ) have shown that prophylactic mesh in sublay position is associated with reduction in parastomal hernia when compared with standard stoma formation
Systematic review including the three RCTs found a statistically significant difference in the incidence of PSH in the mesh gp 12.5% and in the no-mesh gp 53%, but no difference in morbidity
[Shabbir J, Chaudhary BN, Dawson R. A systematic review on the use of prophylactic mesh during primary stoma formation to prevent parastomal hernia formation. Colorectal Dis 2012;14(8):931-6.]

34. RCTs Study Patient types No. of patients Type of mesh
Operative technique
Serra Aracil
elective
Mesh 27,
no mesh 27
Ultrapro (polypropylene + polygelcaprone 25)
Sublay
Janes
elective & emergency
Vypro (polypropylene + polyglactin 910)
Hammond
Mesh 10,
no mesh 10
Permacol (porcine derived crosslinked collagen implant)

35. RCTs (cont) Loss to follow up Study Randomization Blinding
Evaluation of hernia
Follow up / months
Mesh
No mesh
Serra Aracil
sealed envelope
assessor
Physical examination + CT abdomen
Median 29 (range 13-49)
Janes
not mentioned
Physical examination only
Mean 65.2 (range 57-83)
6/27 at 12mo,
6/21 between 1-5yrs
1/27 before 12mo,
5/26 between 1-5yrs
Hammond
double
Physical examination + stoma site USG
Median 6.5 (range 1-12)

36. RCTs (cont) Parastomal hernia Infection Study Mesh No mesh
Mesh complications
Serra Aracil
6/27 (22.2%)
12/27 (44.4%)
1/27 (3.7%)
Janes
2/15 (13%)
17/21 (81%)
Hammond
0/10 (0%)
3/10 (30%)

37. Conclusion Concerning repair Concerning prevention
Mesh repair result in lower recurrence rate
Mesh techniques did not differ significantly in terms of recurrence or morbidity
Low overall rate of mesh infection and comparable for each mesh repair
Overall laparoscopic repair had no advantage over open repair
Concerning prevention
Meticulous surgical technique
Adequately powered RCTs is still needed before recommendation of prophylactic mesh insertion

38. Discussion