We have herein described an 18-year-old patient with Hunter syndrome treated with the TAPP method for an inguinal hernia. The performance of TAPP repair for inguinal hernias in patients with Hunter syndrome is very rare; this is the first such report according to a PubMed search. Surgeons may avoid TAPP repair for inguinal hernias in patients with Hunter syndrome for various reasons. Most patients with Hunter syndrome develop hernias in early childhood. Lin et al.  reported that patients with Hunter syndrome underwent hernia repair in early childhood (mean age, 4.2 years). Surgeons usually select Potts’ method , LPEC , or laparoscopic direct suture [6, 7] for infants. However, our patient was 18 years old, and few reports have described these methods for inguinal hernias in adults. Additionally, there is no evidence of the usefulness of these methods for young adult patients. Sparkman  reported that 15.8% of patients with an inguinal hernia also had a contralateral inguinal hernia. Patients with Hunter syndrome have a high risk of hernia formation, and a wide hernia orifice was present in this case. Therefore, a laparoscopic approach was selected to check the intraperitoneal groin area on the left side.
Because the pathogenesis of inguinal hernia in Hunter syndrome is an indirect hernia and the patient in this case was short for his age, the methods without a prosthetic mesh could be selected. However, the methods without a prosthetic mesh have a higher rate of recurrence than those with a prosthetic mesh for patients who have stopped growing [9,10,11,12,13,14]. Therefore, we selected TAPP in this case.
Historically, patients with Hunter syndrome had a short life expectancy because of complications such as heart disease and respiratory infections. However, they can now be treated with enzyme replacement therapy with idursulfase. Some trials have proven that enzyme replacement therapy with idursulfase improves the clinical symptoms of patients with Hunter syndrome [15,16,17] and enables these patients to live longer. Therefore, more young adult patients with Hunter syndrome will require surgery for inguinal hernias in the future. The Japanese Hernia Society recommends operations with a prosthetic mesh for inguinal hernias in young adulthood . Therefore, TAPP repair may be a suitable procedure for young adult patients with Hunter syndrome.
We identified two differences between our patient with Hunter syndrome and normal adults undergoing surgical repair of hernias. One is that the abdominal wall of our patient with Hunter syndrome was lithe and soft, like that of children, making it difficult to insert trocars through the abdominal wall (Fig. 2a). Trocar insertion required lifting of the abdominal wall with strings. The other difference is the presence of a network of well-developed veins around the spermatic cord and testicular artery (Fig. 2c). Because no previous reports have described inguinal hernia repair in patients with Hunter syndrome, whether this vein formation around the spermatic cord and testicular artery is common among these patients remains unclear. If this network of veins is a common feature, gentle manipulation is required when dissecting the preperitoneal space.
Patients with Hunter syndrome may develop many complications. In the present case, a convulsion and pneumonia developed after surgery. However, we predicted these complications based on previously published reports of Hunter syndrome [2,3,4]. Therefore, we were able to prevent these complications from becoming severe by performing postoperative management in the intensive care unit and ensuring close cooperation with pediatric specialists.