Introduction

Femoral hernias are a very infrequent occurrence among pediatric patients. In the pre-laparoscopic era, misinterpretation as inguinal hernia was frequent and led to unnecessary attempts for inguinal hernia repair [1, 2]. This situation changed completely with introduction of the laparoscopy for pediatric hernia repair [3]. Careful laparoscopic inspection of the suspicious regions easily allows the identification of the underlying type of hernia. Under the point of view achieved by laparoscopy, femoral hernias were “those that opened medially to the femoral vessels and below the inguinal ligament”. For the treatment of a femoral hernia, different techniques of laparoscopic closure have been reported in the literature [4,5,6,7,8,9].

Herein, we report our experience with an innovative single-port laparoscopic percutaneous extraperitoneal closure (LPEC) of femoral hernia. In our departments, LPEC technique is mainly used for the repair of inguinal hernias in girls.

Material and method

We retrospectively identified in a bi-institutional clinical study six children and one young woman (n = 7), who underwent femoral hernia repair between June 2009 and June 2015. In a further case, the assumed femoral hernia was not confirmed.

We recorded sex, age at presentation, intraoperative findings, skin-to-skin operative times, complications, and follow-up. A total of 2800 children underwent inguinal hernia repair during the study period. The diagnosis of inguinocrural hernias was predominately made by careful clinical examination. Ultrasonographic investigations were only applied in the case of inconsistent presentation.

Surgical method

Laparoscopic percutaneous extraperitoneal closure of femoral hernia (LPEF) is achieved by means of a percutaneously placed peritoneal U-shape suture with integrated transfixation of the hernia sac (Fig. 1).

Fig. 1
figure 1

Laparoscopic view on a left sided femoral hernia. Arrows show the internal course of the U-shape suture

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In detail, we introduce either a 12°, 4.5-mm compact hysteroscope with 2.33-mm working channel (Olympus Surgical Technologies Europe, Hamburg, Germany), or a 0°, 5.5-mm mini-operating laparoscope with 3.5-mm working channel (Richard Wolf GmbH, Knittlingen, Germany) through a single infraumbilical access, as previously described [10], to identify the femoral region.

Subsequently, the peritoneal cavity is percutaneously punctured medially with a 14-G peripheral venous cannula (Vasofix safety® 2.2 × 50 mm; Braun Melsungen AG, Melsungen, Germany) (Fig. 2). Peritoneum around the femoral ring is uploaded as much as possible (Fig. 1). The hernia sac is inverted into the abdominal cavity by means of a forceps inserted through the working channel of the laparoscope and punctured with the cannula to achieve transfixation. A 2 × 0 non-absorbable braided polyester suture is pushed into the abdominal cavity and grasped. After removal of this cannula, a puncture from opposite is performed, and the suture is grasped through the cannula shaft using small flexible urological foreign body forceps (3 Ch/230 mm; Richard Wolf GmbH, Knittlingen, Germany) and externalized. The suture is then extracorporeally knotted, burying the knot epifascially at the level of the inguinal ligament. For insertion of the cannula, the suture material, and knot, tying a single 2-mm puncture wound of the skin is sufficient. This closes the hernia by lifting up the encircled peritoneum of the femoral ring. If possible, the medial umbilical ligament was included into the suture to enhance mechanical stability (Fig. 3).

Fig. 2
figure 2

Transfixation of the inverted hernia sack with the venous cannula is performed

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Fig. 3
figure 3

Suture is extracorporeally tied. The femoral ring is closed and medial umbilical ligament serves as enforcement

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Results

In our series, four of seven cases were diagnosed preoperatively by one experienced surgeon (BY), and in three cases, the diagnosis was established incidentally. In the four cases with assumed femoral, hernia was confirmed with ultrasonography. Demographic data and details of our patients are provided in Table 1.

Table 1 Demographic data, operation times, and time span of follow-up
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In an eighth case (female, 20 years), a femoral hernia was assumed by clinical examination; however, endoscopy revealed unilateral presence of a combination of indirect and direct inguinal hernia (hernia en pantaloon) that was closed with LPEC [3]. The clinical appearance of the hernia en pantaloon was misleading and no ultrasound examination was performed. This patient was excluded from the further study. Laparoscopic exploration of the contralateral side in all cases did not reveal any further inguinal pathology. History of the previous ipsilateral inguinal hernia repair was reported in one child.

In our first case, the presence of a femoral hernia was confirmed by laparoscopy; however, we converted to open repair under laparoscopic guidance. In the consecutive cases, femoral hernia was identified laparoscopically, and repair was performed minimally invasively, as described above. All patients underwent at least one follow-up examination. All patients´ legal guardians were very satisfied with the postoperative cosmetic appearance. During a postoperative observation period between 6 years and 6 months, no recurrence was observed.

Discussion

A femoral hernia is defined as the protrusion of the abdominal contents through the annulus femoralis to the fossa ovalis [2]. This type of hernia had been described the first time by Franz Caspar Hesselbach in 1798 [11]. The anatomical concept of the myopectineal orifice of Fruchaud gives a modern anatomical explanation on the occurrence of both inguinal and femoral hernias [12, 13]. The diagnosis of femoral hernia is made by careful clinical examination. Clinically, a soft and non-tender bulge is seen and felt in projection on the femoral trigon. Ultrasound examination may confirm the diagnosis and it can visualize the content of the hernia sack. Incarcerations of the omentum and bowel may occur [14, 15]. In children, the rate of preoperative misdiagnosis has been reported in more than three-thirds of cases [2, 8, 15, 16].

Femoral hernias are rare. In a meta-analysis of three large studies on pediatric femoral hernia, the relative incidence of femoral hernia was 39 cases out of a total of 12,126 inguinal hernia repairs (0.32%) [14, 17, 18]. Our incidence during the study period was lower with seven cases of a total of 2800 inguinal hernia patients (0.25%). One study found a ratio of 1.1% in a highly selected cohort [3]. In our departments, inguinal hernia repair in girls is predominately performed by laparoscopy. In selected cases, laparoscopy is provided for male hernias. Contradictory to our results (5 girls, 2 boys), exclusively male patients were reported in another single institution series [3]. According to larger cohorts, the age at presentation with femoral hernia varied between 6 weeks and 15 years, and there was a slight female predominance (1.2-fold more females) [14, 17, 18]. In a Japanese report, the sex ratio of 3:2 showed a more pronounced female prevalence [15].

It is thought that femoral hernias are predominately acquired conditions, and there is never a preformed congenital peritoneal sac. The vast majority of femoral hernias are unilateral; however, bilateral cases may occur [14,15,16,17]. Anatomical variations in individuals can predispose to the development of femoral hernia in the presence of acquired predisposing factors. In adults, multiparous and obese women aged over 50 years are predominately affected [19]. In the presented series, no patient suffered from predisposing etiological factors like chronic pulmonary disease or obesity, and only one girl had the previous inguinal hernia repair during the early childhood. It has been reported that recurrences after open inguinal hernia repair often present as femoral hernias [4, 16, 18].

Surgery of femoral hernia is based on anatomy. The femoral ring is defined as the small opening between the pectineal ligament touchdown of the iliopubic tract and transversalis fascia and the external iliac vein [13]. The boundaries of the femoral ring are anterior, the inguinal ligament; posterior the pectineus fascia and underlying muscle; lateral the external iliac/femoral vein; and medial the iliopectineal (Cooper’s) and the lacunar (Gimbernat’s) ligament.

Techniques of open femoral hernia repair in childhood can performed via the supra-inguinal or the infra-inguinal approach. At open inguinal hernia repair, the femoral ring can be visualized by incision through the inguinal canal and the transversalis fascia with subsequent high ligation or inversion of the hernia and closure of the femoral ring [14, 17, 20]. For narrowing the femoral ring, Cooper’s ligament was sutured to the inguinal ligament. The classical technique according to McVay uses a transversalis fascia pedicle flap to close the femoral canal. To facilitate the open infra-inguinal closure, identification and liberation of the hernia sac can be supported by laparoscopic transillumination.

It has been demonstrated that laparoscopy allows an objective view of the anatomy of unusual hernias of the internal inguinal region in infants and children [3]. For laparoscopic repair, different techniques were applied. In general, intracorporeal or alternatively extracorporeal percutaneous methods can be performed [21]. It has been reported that simple hernia sac ligation alone may be not sufficient for a long lasting repair. Laparoscopic exposure and closure of the defect by incorporation of subperitoneal fascial tissue into the suture was successful in one series [3]. Different techniques with or without the use of patches or plugs were reported to prevent relapses. Laparoscopic identification and assistance in combination with a small infranguinal incision (hybrid technique) was predominately reported in the laparoscopic literature [4, 6, 9]. Some authors propose the use of alloplastic non-absorbable prosthetic material even in children [4, 8, 9, 22]. According to our philosophy, we avoid the use of non-absorbable mesh plugs or patches. Foreign body reaction, irritation and erosion of surrounding tissues, and a lifelong persistence of non-absorbable tissue may carry incalculable risks. In one single case report, the umbilical ligament was applied as a plug for laparoscopic repair, different techniques were applied (Table 2) [5].

Table 2 Pediatric series of laparoscopic femoral hernia repair, techniques, and results
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Our technique is based on the transfixation of the inverted hernia sac, which is lifted up together with the encircled femoral ring. This maneuver allows the mechanical stable closure of the hernia. This technique is a modified and anatomically adapted version of the method proposed by Endo et al. for pediatric inguinal hernia repair [23]. The procedure is not technically demanding and standard operating room equipment is used. The single use venous safety cannula always allows a smooth passage of the abdominal wall. An additional infraumbilical incision was avoided in the last six patients. With only one umbilical wound and the nearly invisible inguinal puncture, the cosmetic outcomes were excellent.

Our study has several potential limitations. The number of patients is small and the length of follow-up is short. The neighborhood of the external iliac vessels requires a meticulous technique to avoid narrowing of the vein and bleeding.

Despite these potential limitations, the authors are convinced that laparoscopic groin exploration and femoral hernia repair in children and adolescents is a safe alternative to open repair. However, we agree with the statement of Puri et al.: “no surgeon has enough experience to prefer one particular technique above another” [16].

In conclusion, we present an easy to do single-port percutaneous technique for femoral hernia repair in children and adolescents. Transfixation of the inverted sac, uplifting of the closed femoral ring to the inguinal ligament, and incorporation of the umbilical ligament are the main principles of this technique. The authors advocate LPEC for the repair of pediatric and adolescent femoral hernias.