Inguinal hernioplasty using mosquito net mesh in low income countries: an alternative and cost effective prosthesis
BMJ 2011; 343 doi: https://doi.org/10.1136/bmj.d7448 (Published 15 December 2011) Cite this as: BMJ 2011;343:d7448
- 1Department of Surgery, Royal Gwent Hospital, Newport, South Wales, NP20 2UB, UK
- 2Department of Surgery, Derriford Hospital, Plymouth, Devon, UK
- Correspondence to: B M Stephenson brian.stephenson{at}wales.nhs.uk
In many parts of the world the burden of untreated hernias, particularly inguinal, is high and those who work in advanced healthcare systems may believe that little can be done. In addition, many low income countries consider elective surgery to be a low priority. Indeed in parts of Africa many patients develop large inguinoscrotal herniation as a result of delayed presentation, and the need for emergency surgery with its attendant mortality is not uncommon.
Although those who work in developed countries fully appreciate the benefits of alloplastic (synthetic) mesh in the repair of inguinal hernias,1 this is still not commonly used in poorly resourced communities. Availability and cost of such meshes are generally prohibitive to both surgeons and patients. Although the benefits of Lichtenstein tension-free repairs (earlier return to work and a lower long term recurrence rate)2 are well appreciated by African surgeons, a traditional sutured repair (Bassini technique) is still common.3 This can best be described as a low cost approach that has been clearly satisfactory in the past. Can this now be superseded by the introduction of a widely available and distinctly cheaper mesh to improve the results of repair and quality of life?
Hernioplasty using mosquito net mesh
Although commercial nylon (polyamide 6-6) has been used for over 60 years as suture material, in some low income countries sterilised nylon fishing line, bought locally, is still used as a cheaper alternative.4 Given that this has proved a safe option, the next logical step was the use of a net of similar material as a mesh in the repair of inguinal hernias.
The Indian surgeon Tongaonkar must be credited for popularising this novel concept, although he attributes the idea to his coauthor Reddy.5 A non-insecticide impregnated copolymer (50% polypropylene:50% polyethylene) mesh from mosquito nets was used in 359 repairs in a four centre (including rural settings) audit of various abdominal wall hernias over a six year period. Most of these hernias (278/419, 67%) were inguinal, and overall the repairs were well tolerated. Minor wound sepsis (not requiring mesh excision) was noted in about 5% of patients. Although follow-up was not strict, only one case of recurrence (0.3%) was documented. Indeed, as commercial meshes had also been used in some patients, concerns about early infection were inadvertently addressed as similar rates of sepsis (7%) were noted when prolene or marlex mesh was used.
The wider clinical application of these data was tested in Burkina Faso, west Africa in an ethically approved randomised design carried out by visiting German surgeons.6 Forty consecutive well matched unselected inguinal hernias were repaired with either a commercial mesh (Ultrapro (polyglactin/polypropylene), Ethicon) or a similar sized sheet of locally bought and sterilised mosquito mesh (100% nylon). The outcome was assessed with an African adaptation of the SF-36 form for quality of life items. All patients significantly improved postoperatively, although no difference was reported between the mesh groups. The cost to the patient was noticeably different, however, at about 25 000-fold.
Clearly the next step was to look at locally obtained mosquito net mesh for its biocompatibility, since a foreign body reaction is generated when any type of mesh is used to augment a hernia repair. Indeed wounds have a different response to mesh than the healing process observed after sutured repairs.7 This uncertainty is clearly problematic in humans, and animal studies are necessary. Goats in Uganda were subjected to numerous careful analyses at four and 16 weeks after mesh implantation on the posterior sheath of the rectus abdominis muscle.8 Mosquito net meshes containing 100% nylon were compared with meshes containing 100% polypropylene meshes (Surgipro, Tyco Healthcare), and although both comprised monofilament fibres they varied to some extent for other properties such as weight, pore size, thickness, and tensile strength. No complications occurred. The only difference was a longer and slightly more intense inflammatory response with the mosquito net mesh.
Operation Hernia
Operation Hernia is an independent UK based charity, established in 2005 when a team of European surgeons got together to establish a link between Derriford Hospital, Plymouth and a government hospital in Takoradi, western Ghana. Operation Hernia primarily acts as a surgical programme to treat hernias and teach hernia surgery in low income countries, particularly those on the African continent (www.operationhernia.org.uk). The programme is committed to providing high quality abdominal wall (especially inguinal) surgery at minimal costs to patients who would otherwise not receive treatment.
On our first mission in 20059 we used commercially donated mesh to treat 123 patients with inguinal hernias. In 2007, and as a consequence of evolving favourable literature, we introduced sterilised mosquito net mesh to Ghana.10 This was donated by Scotmas (www.scotmas.com), a company that manufactures hygiene and environmental care products, and consisted of 100% polyester with reinforcing threads, which was cut and sterilised locally. A total of 106 meshes were used to repair inguinal hernias in 95 patients. At six months follow-up, seven (7%) patients had minor wound complications but no recurrences. Owing to the surgeon’s unfamiliarity with the material, ease of handling improved after two to five cases. The cost of an individual mesh, including sterilisation and packaging, was negligible and estimated at about $2.00 (£1.26; €1.50). This price is significantly lower than that in the developed world for a similar sized piece of mesh produced commercially ($40 to ≥$50).
Although Tongaonkar had been using mosquito net mesh for some time we only heard about it in 2008, as his pioneering contribution was not cited by PubMed or Medline. We obtained some samples of the mesh and found it to be very surgeon friendly. On a mission to the Ivory Coast in late 2010, we cut the donated mesh to size (fig 1⇓) and steam autoclaved it for 25 minutes at 121ºC allowing for a predetermined cross sectional shrinkage of about 30%.11 Over four days we used the mesh to repair the hernias of 54 patients (60% with large inguinoscrotal hernias), mainly under local anaesthesia as day cases. Oral antibiotic prophylaxis was given for five days postoperatively, and at six weeks’ follow-up no complications were recorded. The cost of the mesh was low (<€2 for 10×12 cm), including sterilisation and packaging. The mesh handled well, did not fray on cutting, and felt softer than the polyester mosquito net mesh previously used by Operation Hernia since 2009. In all future missions Operation Hernia plans to use the mosquito net mesh because of its handling properties.
Fig 1 Cutting a large sheet of mosquito net mesh to size before sterilisation
Since the inception of Operation Hernia, numerous surgeons, operating in teams, have volunteered their time to teach (fig 2⇓) and treat underprivileged people. Over 50 missions have taken place since 2005, with more than 4000 people treated, principally in west Africa.
Fig 2 Teaching the principles of tension-free mesh hernioplasty
Discussion
Both clinical and experimental evidence5 6 8 10 supports the use of indigenous mosquito net meshes to augment the repair of inguinal hernias to achieve results similar to those of developed countries.
The mosquito net mesh has many of the features of modern meshes at a fraction of the cost: they are made of similar monofilament material to those commonly in use with comparable weight, pore size, elasticity, and biocompatibility or reactivity. In the past six years only two patients treated by Operation Hernia have required mesh excision owing to infection, regardless of whether commercially available or mosquito net mesh was used. Nevertheless, the need to be fastidious about sterility cannot be overstated and needs to be stressed before rural surgeons use locally acquired mesh on a regular basis. It would seem that mosquito net meshes are easily sterilised locally, although at different temperatures and for varying times to maintain sterility and mesh integrity.5 6 8 10 11 In addition a short course of antibiotics as a precaution against potentially unhygienic conditions in the patient’s home would be advisable.
Where do we go from here? Operation Hernia is now using donated pre-cut ethylene oxide sterilised (in the United Kingdom) mosquito net mesh for the repair of inguinal hernias. With more formal audit and stricter follow-up locally we will be able to answer the question of whether such an approach does safely allow mosquito mesh hernioplasty without an increased risk of sepsis11 and with the lower recurrence rate to which we are all accustomed.
Given that mosquito net meshes are clearly affordable compared with those promoted by commercial companies, hopefully the elective repair of inguinal hernias will be given greater priority in developing countries. Mosquito net mesh technology has been clearly tested and the product should be universally accessible; it certainly seems satisfactory to both surgeons and patients.12 Nevertheless, before global acceptance is achieved, including that of commercial companies, careful audit and follow-up is required, which could involve many barriers in the African setting.
Finally, is there evidence that these propositions actually improve outcomes by reducing a patient’s disability? Political and public health decisions often need to be fostered and then strengthened by firm data. In this respect disability adjusted life years (DALYs) can be used to confirm or refute the economic benefit of such interventions.13 One DALY represents the loss of one year of equivalent work that someone could accomplish when in full health. In a study of 113 patients undergoing elective mosquito mesh hernioplasty by Operation Hernia, an average of 9.3 DALYs per patient were averted at a cost of less than $13 per DALY averted.14 For comparison, the costs for averting a DALY are $2 for tetanus immunisation, $9 for the removal of a cataract, and $1300 for tibial nailing. Therefore $13 per DALY averted is surely not a figure that any public health system should ignore, irrespective of the resources being spent on other disease burdens such as AIDS and malaria. Mosquito nets are clearly valuable in more ways than one.
Notes
Cite this as: BMJ 2011;343:d7448
Footnotes
Competing interests: All authors have completed the ICMJE uniform disclosure form at www.icmje.org/coi_disclosure.pdf (available on request from the corresponding author) and declare: no support from any organisation for the submitted work; no financial relationships with any organisations that might have an interest in the submitted work in the previous three years; and no other relationships or activities that could appear to have influenced the submitted work.
Provenance and peer review: Not commissioned; externally peer reviewed.