This document proposes a percutaneous approach to repairing inguinal hernias in children as an alternative to open or laparoscopic surgery. The approach, called percutaneous obliteration of patent processus vaginalis (PO-PPV), involves accessing the processus vaginalis percutaneously under imaging guidance. An adhesive is then injected to obliterate the cavity. The document describes a rat model experiment that demonstrated PO-PPV is effective at obliterating the processus vaginalis based on imaging and inspection, and was safe with no effects on fertility, though some tissue inflammation occurred. It concludes PO-PPV shows promise but challenges around the adhesive and ensuring long-term effectiveness and safety need

1. Percutaneous Obliteration of Patent
Processus Vaginalis
A Rat Model for Future Inguinal Hernia
Repair in Children
Yassir Assiri, Saad Al-Kahtani
5th year medical student
KSU

2. Inguinal Hernia Repair in Children
• Inguinal hernia affects 3.5-5% of all full term
infants and 9-11% of premature babies
• Hernia surgery is one of the commonest
procedures performed by pediatric surgeons Glick PL , 2007
• Failure of in-utero Processus Vaginalis obliteration
is believed to be the main pathology

3. (PPV)

4. Seen#2 (still photo): normal closed
canal (processus vaginalis)

5. Current options for treating symptomatic Patent
Processus Vaginalis (PPV) in children
1. Open inguinal herniotomy (most popular) Ein SH, 2006 & Vogels HD 2010
– Painful inguinal incision
– Possible injury to vas deference and testicular vessels
– Risk of chronic pain and numbness due to ileo-inguinal nerve injury
2. Laparoscopic hernia repair Schier F,2002 & Chan KL, 2007
– Higher recurrence rates
– Postoperative hydrocele formation
– Possible injury to the vas and gonadal vessels
– Higher cost concerns. McCormack K, 2005
3. Mini-scar inguinal herniotomy Al-Jazaeri et al, 2011
– Small incision but difficult to perform
– Not for all children
– Risk of vas & vessels injury

6. Per-cutaneous approach has been the
natural evolution for many open
surgeries
• Deep cavity abscess drainage
• Coronary stenting
• Cerebral aneurysm treatment
• Fetal intervention (PUV, Twins transfusion..)
• Tumor ablation and embolization (liver, kidney,..)
• Aortic Aneurysm repair
• Heart valve replacement
…and the list is growing

7. Percutaneous
Obliteration of Patent Processus Vaginalis
(PO-PPV)
A Possible
Future Model for Inguinal Hernia Repair
in
Children

8. The Current Challenges…
• How to access the thin PPV?
- Very thin membrane
- Collapsed
• How to avoid injuring other structures while
accessing PPV?
-Bowel
-Vas deference
-Testicular vessels
• How to effectively obliterate the PPV ?
- Achieve a complete closure
- Avoid recurrence

9. The concept of our experimental
design…
Percutaneous Obliteration of PPV (PO-PPV)
Inflate PPV
with air
Per-cutaneous
access
Inject tissue
adhesive
Obliterated
PPV
Cannula
(V.needle)
pneumo-
peritoneum
Insert a
cannula while
aspirating
2-octyl-
cyanoacrylate
radiological &
histological
analysis

10. The adhesive molecule
2-Octyl-Cyanoacrylat (2-OC)

11. 2-OC + H2O  Polymerization
=> Adhesive effect
Liquid  Plastic-like bonding molecule

12. Insufflators

13. Our poor patient….

14. Inducing pneumoperitonium

15. Intra-peritoneal cannula insertion
Cannula is introduced while aspirating
Air indicates intra-
peritoneal position
In future human model  the cannula can be introduced
directly into the inflated inguinal canal
Inflated abdomen

16. The cannula is advanced through the
PPV

17. Two cannulas are used for bilateral
PO-PPV

18. 2-OC is injected inside the PPV while
2-OC (blue)
External pressure is
applied to prevent
intra-abdominal leak

19. Two cannulas are used for bilateral
PPV obliteration

20. Air is then injected to minimize rapid
polymerization of 2-OC by the peritoneal
H2O

21. External pressure is maintained for 5-min

22. Experimental Groups
4 weeks old Lewis
rats
Unilateral PO-PPV
(n=11)
Bilateral PO-PPV
(n=15)
Sham
(saline injected)
(n=14)

23. Outcomes …
• Effectiveness (PPV obliteration)
– Herniography
– Gross post-mortum inspection
• Safety of vas & testicular tissue
– Post-mortum hitological analysis
• Vas patency
• Testicular changes
– Treatment group fertility

24. The Experimental Timetable
Week #4
•Procedure (PO-PPV)
Week #6
•Mating
Week #8
•Herniograpahy
Week # 12
•Sacrificed -> histology
Rat age
IRB approval

25. Herniography…
Effectiveness (PPV obliteration)

26. Shame group
Herniography
Contrast is seen
around testis due
to Patent PV
Sham group

27. Shame group
Herniography
Contrast is passing
through PPV
Sham group

28. Herniography Obliterated
PV
Patent PV
Unilateral PIH group

29. Herniography
Unilateral PIH group

30. Herniography
Unilateral PIH group

31. Bilateral PPV obliteration
Herniography
Obliterated PV
Contrast filled
abdomen
Bilateral PIH group

32. Bilateral PPV obliteration
Herniography
Bilateral PIH group
Obliterated PV

33. Effectiveness (PPV obliteration)
Sides Sham (n=14) Unilateral (n=11) Bilateral (n=30)
PPV Obliteration
Herniography (sides) 0 11 (100%) 25 (83.3%)
Post-mortum PV
analysis (sides)
0 11 (100%) 30 (100%)
Both sides
are treated

34. Histology…
Safety...

35. Histological Analysis
Sham (n=14) Unilat (n=12) Bil (n=30)
Fibrosis
None 14 12 28
Moderate 0 1 2
Sever 0 0 0
Fat necrosis
None 13 1 4
Moderate 1 8 13
Sever 0 3 13
FB reaction
None 13 1 4
Moderate 1 8 13
Sever 0 3 13
Vas patency
(gross&histology)
Patent 14 12 30
Narrowed 0 0 0
Obliterated 0 0 0

36. Normal vas deferens mucosa and muscular wall.

37. Normal and patent Vas Deferens with a focus of gaint cells reaction

38. Calcification
Calcification
Calcification

39. Safety...
Fertility (mating)
+
X1 Boy X 2 Girls

40. All rats were fertile after mating
Safety...
Fertility (mating)

41. Limitations and future plans
Challenges Solution / Alternative Strategy
Rapid polymerization in H2O
(peritoneal fluid)
Marine Biomimetics
Adhesives
Low viscosity  intra-peritoneal leak Mix with alginate (inert thickening
agent derived from seaweed)
Safety of foreign body inflammatory reaction
induced by 2-OC?
Mesh has long track record of safety in
adult inguinal hernia
Long term effectiveness and safety Larger animal model and long follow up
is needed

42. Marine Mussel Adhesion
The future of tissue adhesives
blue mussel, Mytilus edulis
Produce adhesives that work in aquatic environment
Wide potential applications in surgery and dentistry

43. Conclusion
Per-cutaneous obliteration of PPV is possible and safe
in animal
Some challenges have to be addressed before the safe
and effective transfer to human
Percutaneous hernia repair is likely to be the next step
in the evolution of hernia repair
for both
children and adults

44. Thank you
Simplified Animation….

45. References
• Glick PL, Boulanger SC. Inguinal hernias and hydroceles. In: O'Neill JA, Rowe MI, Grosfeld JC, et al,
editors. Pediatric surgery, 5th edn, Mosby, St Louis 2007, 1172-92.
• Ein SH, Njere I, Ein A. Six thousand three hundred sixty-one pediatric inguinal hernias: a 35 year
review. J Pediatr Surg 2006;41:980–6
• Vogels HD, Bruijnen CJ, Beasley SW. Establishing benchmarks for the outcome of herniotomy in
children. Br J Surg 2010;97:1135-9
• Schier F, Montupet P, Esposito C. Laparoscopic inguinal herniorrhaphy in children: a three-center
experience with 933 repairs. J Pediatr Surg 2002;37:395-7.
• Chan KL, Chan HY, Tam PK. Towards a near-zero recurrence rate in laparoscopic inguinal hernia
repair for pediatric patients of all ages. J Pediatr Surg 2007;42:1993-7.
• McCormack K, Wake B, Perez J, Fraser C, Cook J, McIntosh E, et al. Laparoscopic surgery for
inguinal hernia repair: systematic review of effectiveness and economic evaluation. Health
Technol Assess. 2005;9:1–203, iii–iv.
• Al-Jazaeri A, Al-Hassan N, Al-Hassan B, Harakati D, Al-Hezayen R, Al-Zahem A. Mini-Scar Inguinal
Herniotomy in Selected Children: Comparative Analysis of Safety, Effectiveness and Parents’
Satisfaction. J Laparoendo surg tech, 2011
• Silverman HG, Roberto FF. Understanding Marine Mussel Adhesion. Mar Biotechnol (NY). 2007
December; 9(6): 661–681.