Recently, there are several reports concerning complications after hernia repair with a mesh plug. According to the reports, mesh migration was observed in the preperitoneal space, small intestine and colon, and scrotum [2-7]. There was one case that reported that the mesh had migrated into the bladder after endoscopic repair [8] but we could not find any reports that the mesh plug migrated into the bladder by searching English language MEDLINE. In our case, more than half of the mesh plug had penetrated into the bladder, pointing to a mesh plug migration into the bladder.
The question is how mesh plug migration occurs. In a review article on mesh plug migration cases, the authors claim that surgical technique was poor in some cases, one case did not show true migration, another one was a case of the wrong operation being done, and one case due to the patient's very poor health [9]. They concluded that this kind of complication could be avoided by careful operation. There are no obvious reasons why the mesh plug migrated into the bladder in our case. However, when considering the reported reasons above, it might be possible to make a hypothesis. First, the body weight of this patient was 37 kg at the time of the inguinal hernia operation. As she also suffered the aftereffects of a subarachnoidal hemorrhage, it can be assumed that the patient's health was poor. This condition may cause problems to sufficiently fix the mesh as other reports indicated [7,9]. Second, as the inguinal hernia was a direct hernia, the mesh plug was inserted into the transversal fascia, and this position is in the vicinity of the bladder. Due to the patient's poor health, it is easy to imagine that the adipose tissue between the mesh and the bladder might have been thin, and this caused a condition in which the mesh plug was pressed against the bladder wall each time the urine was collected in the bladder. This might have ruined the fixation of the mesh plug and finally the hard tip of the mesh plug penetrated the bladder and migrated.
Furthermore, we found that the removed mesh plug and the onlay mesh slightly shrunk compared to their original size but not stiffened as reported [2] and with no granulation attracted (Figure 3c). This suggests that the penetration into the bladder might have occurred far earlier, and the wet environment prevented the mesh from becoming stiffened and from developing granulation. Perhaps, a genitourinary infection has occurred at a later point of time, and the mesh was then infected.
We changed the type of the mesh plug to ProLoop plug (Atrium, Hudson, NH, USA) after we experienced this case, a far less stiff mesh plug than the formerly used PerFix plug. Though there is not yet sufficient report on that, we have come to believe that this type of complication is at least partially caused by the stiffness of the mesh plug. At least in cases like ours, a soft plug should ease the tension between the bladder and the fixation of the plug compared to a hard type plug. This might prevent damage to the fixation site and also prevent the penetration into the bladder and, thus, may avoid this complication altogether. We are fully aware that open methods such as Kugel or Prolene hernia system might prevent this kind of complication in the first place. However, the mesh plug system is quick, easy to learn, and low cost, so we consider this one of the standard procedures for inguinal hernia repair. Furthermore, a randomized control study comparing Lichtenstein patch, PerFix plug, and ProLoop plug [10] reported that though there were no significant differences among the groups in operative time, hospital stay, bodily pain scores, and complication rates, the authors concluded that the ProLoop plug is a safe and effective method of repairing inguinal hernias. Its novel lightweight configuration does not increase the risk of recurrence when compared to thicker mesh plugs, and it may offer benefits in patient comfort.
