HOW TO PREVENT INGUINODYNIA-AFTER TENSION-FREE INGUINAL HERNIA REPAIR – OUR EXPERIENCE

Inguinodynia is persistence of pain for more than 3 months after inguinal hernia operation. Chronic pain may be associated with hyperesthesia or hypoesthesia. This pain may be mild, moderate or severe. Inguinodynia may even effect quality of life. Pain may resolve on its own or after conservative treatment. Sometimes it persists and conservative methods fail then various other modalities of treatment are considered including re-exploration and neurectomy. We performed all 396 inguinal hernia repair by a modified Lichtenstein tension-free procedure. In our series of 396 cases inguinodynia happened only in 3 cases, a real low incidence. Some researchers have reported the incidence of inguinodynia as high as 19 percent 1 year after operation. No case required reexploration, removal of mesh or neurectomy in our series.


Introduction:
Seroma is a collection of serum at the site of operation. Seroma is formed due to tissue dissection and can occur in any patient after groin hernia surgery. Use of mesh to cure hernia is also responsible for seroma. Patient of hernia repair with mesh are at higher risk of developing seroma. Seroma appears like a lump in the groin at the site of surgery. It is a selflimiting problem but sometimes requires several aspirations. Aspiration has a danger of introducing infection so aspiration must be done with aseptic precautions, otherwise seroma fluid can become infected & can develop an absecess. General incidence of seroma is reported between 1.2 to 10%. It is due to trauma to the lymphatics due to the surgical dissection. It is felt that abdominal binder reduces the chance of seroma formation as it does not allow it to grow. Daniel B Jones states 1 his experience that "During the years, I have recommended an abdominal blinder to potentially decrease the post-operative seroma". Small seroma can heal without any treatment but with reassurance. Larger the hernia larger chance of seroma development. We have operated upon 400 cases of inguinal hernia by modified Lichtenstein's tension free hernioplasty, called Nigam's inverted curtain hernioplasty (NICH). 2 Seroma developed in only 6 cases (1.5%). The international incidence of development of seroma after groin surgery is approx 7%. In NICH we do minimum tissue dissection, use minimum sutures to fix the mesh, double breasting of external oblique aponeurosis (it applies pressure and removes dead space) and dressings with Elastoplasts, an elastic adhesive tape. Elastoplasts also applies extra pressure over operation sit and helps in preventing dead space formatting and seroma formation. These operative steps in NICH help to reduce the incidence of seroma formation.
The size of the collection relates to the amount of dissection done between tissue planes and the amount of empty space in the surgical wound 3 . The exact pathogenesis of seroma matter of debate. It has been postulated to be due to a local inflammatory response to the mechanical injury incurred by tissue dissection, as well as to the introduction of foreign material into the body 4 . The main risk factors are advanced age big hernia sac, scrotal hernia, and transaction of the sac with distal part left behind. Because it mimics a postoperative recurrence of hernia, seroma has been concern to hernia patients 5 . Seroma formation after laparoscopic inguinal hernia repair is reported with various rates (1.9%-22.9%) 6.7 .
Seroma formation can be reduced and even prevented by sharp dissection and less cautery, in large indirect hernias transect sac in the inguinal canal rather than complete stripping from spermatic cord structures, always explain the patient specially in big hernias the possibility of developing seroma post-operatively as it will be a matter of concern for the patient. Putting a drain in large hernia helps to avoid seroma formation. Try to avoid dead space formation in big hernias. In inguino-scrotal hernia put a drain through scrotum. Good haemostasis is must to avoid seroma formation.

Methods
A total of 400 inguinal hernia repairs were done for primary uncomplicated indirect, direct and bilateral inguinal hernias by a modified Lichtenstein tensionfree repair, NICH (Nigam's inverted curtain hernioplasty) between March 2000 and December 2020 (Table I), in Max Hospital and some other hospital of grogram, Haryana, India. Informed consent was taken from all patients. All patients were operated by same NICH technique.
All patients were prepared for the procedure in the conventional method and surgery was performed under local, spinal or general anaesthesia. After skin incision, the external oblique aponeurosis was incised above the midline of superficial inguinal ring. The area where the mesh was to be placed (the mesh bed) was prepared by making space between external oblique aponeurosis and internal oblique muscle with finger wrapped up with gauze. This procedure should be done slowly under vision without much force as ileohypogastric nerve can be damaged. A minimal tissue dissection was done keeping in mind the tissue trauma. Indirect inguinal hernia sac was transfixed and excised. In large inguinoscrotal hernias the sac was cut in inguinal canal and distal part of sac was not dissectd out and stripped from spinal cord structures. Direct inguinal hernia sac was reduced and plicated. In all cases a15 cm x 15cm polypropylene mesh was used and 2-0 polypropylene sutures were used to fix the mesh. The mesh was cut and shaped according to the space available and size of myopectineal orifice of Fruchaud. Two sutures were used to fix the mesh with inguinal ligament. No suture was applied to fix the main body of the mesh, which remained free like an inverted curtain. The external oblique aponeurosis was then closed with 2-0 polypropylene suture in semi double breasting manner. The margin of the upper flap was sutured with the lower flap one cm inferior to the margin, on the surface. Subcutaneous tissue was approximated with only three absorbable sutures. Care was taken to avoid dead space formation.
The wound was closed in the conventional manner. Povidone-iodine solution soaked gauze dressing was applied over wound in every cas. Elastoplasts, an elastic tape, used to fix the dressing which applied some pressure to avoid seroma formation. Patients were discharged within 24 hours. Ambulation was not restricted. Patients were advised to takes oral antibiotics for 3 to 5 days. Patients were called for follow-up on the 8 th post-operative day. Sutures were removed on the eighth to tenth post-operative day.

Discussion
Seroma development following inguinal hernia repair is a known post-operative problem, most seromas will resolve spontaneously without requiring any intervention 8 . However, large seromas can be symptomatic, causing pain and discomfort to patient. Aspiration is one of the simplest ways to treat seromas. However, it can be uncomfortable and possesses a risk of bacterial contamination 9 .
A study of Lichtenstein's hernioplasty on 90 patients reported 11.1% incidence of seroma 10 which means higher than the incidence in our NICH study. Friis and Lindahl observed seroma formation in four cases (3.9%) in a 102 case study of tension-free hernioplasty with prolene mesh 11 . We have seen that the risk of seroma increases strongly in the case of strangulated and incarcerated hernia among hernia operations using mesh….. strangulated or incarcerated hernia increased the risk for the development of the seroma.
A BMI over 30kg/m 2 increased the risk of developing seroma 4.3 fold in multiple binary logistic regressions. Ghnnam etal showed that seroma is related to BMI in their study 12 . It is observed that obesity may increase incidence of seroma formation after open inguinal hernia repair.
In another study Sodergren and Swift found the seroma rate 4.5% for laparoscopic ventral hernia repair operations, and they especially emphasized that seroma dependent on dead space in the remnant hernia sac 13 .
We feel that type of anaesthesia has no role in seroma formation. Lichtenstein reported that they performed non-tension mesh repair under local anasthesia 14 .
However, it is stated that there is no significant difference between local, spinal and general anaesthesia in inguinal hernia repair 15 .
Park etal reported that if seroma in laparoscopic repair of incisional hernia is symptomatic and persists longer than 6 weeks, it should be viewed as a complication 16 .
In NICH any change of posture, from lying position to standing or walking and running will not put any extra focal strain on the mesh causing maldistribution of tension, leading to wrinkles and dead space formation 2 .
Some workers applied tetracycline solution over the mesh before closing the wound in order to reduce the incidence of seroma. Emin Turk, etal studied the effect of topical tetracycline on seroma formation after Lichtenstein repair in 96 patients and found no beneficial effect of using topical tetracycline on seroma development in grafted hernia repair 17 .
We feel that to reduce the incidence of seroma formation after inguinal hernia repair, we must do minimal tissue dissection, meticulous repair, minimum number of sutures, avoidance of dead space, maintenance of harnostable and preventive of haematoma formation and dressing of the operation site by an elastic dressing.
Theoretically the occurrence of seroma and haematoma may lead to an increase in the displacement of hernia patches, which increases the risk of post operative recurrence 18 . Data for several studies suggested that laparoscopic hernia repair was associated with higher rates of haematoma and seroma formation 19 .
As noted in a study conducted by Schmedt etal, hematoma and seroma may be present but unnoticed 20 . In our study post-operative follow-up was done by either of the authors so chances of getting unnoticed seroma was zero as in other studies the post operative follow up and dressing were done by an OPD nurse.