Diagnosis and treatment of a rare case of an incarcerated bilateral Spigelian hernia with the vermiform appendix and caecum

Abstract

Spigelian hernia is a rare form of abdominal wall defect. Bilateral Spigelian hernias are even less common. Surgical repair of Spigelian hernias is recommended due to their high risk of incarceration and strangulation of abdominal contents. A variety of surgical approaches to repair these hernias have been described in the literature including the traditional open approach, laparoscopic transabdominal preperitoneal approach, laparoscopic intraperitoneal repair and laparoscopic totally extraperitoneal repair. Here, we present the case of an elderly female patient with rare bilateral Spigelian hernias, the right side containing incarcerated appendix and caecal pole. The left hernia was unrecognised on preoperative CT imaging. To our knowledge, very few cases have been reported in the literature. The patient underwent bilateral laparoscopic intraperitoneal mesh repair. All technical aspects of the treatment are discussed here, in the context of the current literature, including the surgical technique and the limitations of the CT diagnosis. We aim to summarise the background of these uncommon hernias, the limitations of preoperative investigations and the differences between the available operative approaches.

Background

In Spigelian hernias, the defect is usually small, well defined and occurs within the transversus abdominis aponeurosis. The term ‘Spigelian hernia’ was introduced by Flemish anatomist Josef Klinkosch in 1764 and named after Adriaan van den Spiegel or Adrianus Spigelius, an anatomist, who was the first to describe this rare hernia in 1627. It most commonly occurs in the lower abdomen where the posterior rectus sheath is absent. The defect lies adjacent to the semilunar line running from the tip of the ninth costal cartilage, down along the lateral edge of the rectus muscle, to the pubic spine (figure 1). The incidence of Spigelian hernias has been reported to be between 0.12% and 2% of all abdominal wall hernias,^1–5 with bilateral hernias accounting for 3% of all cases.^{6 7} Most Spigelian hernias are acquired, however, some may be congenital and in male paediatric patients there is a significant association with cryptorchidism.^{8 9} The hernia and contents may lie in an interparietal location with no obvious mass to find on clinical examination, making the diagnosis of Spigelian hernias problematic. This differs from most common abdominal wall hernias that traverse the full thickness of the abdominal wall and commonly present with a palpable mass. Spigelian hernias often require cross-sectional imaging to establish the definitive diagnosis. Various operative approaches to repair have been described, with most current evidence supporting a laparoscopic approach. The most frequently described laparoscopic approach is the transabdominal technique.

Figure 1.

Anatomical location of Spigelian fascia and most common area of herniation. (Original author NRL).

Case presentation

The female patient in her 80s presented to the emergency department (ED) with a short history of lower abdominal pain, nausea and loose bowel motions. Comorbidities included glaucoma and hypertension. There was no history of any trauma, and the patient had undergone no prior abdominal surgery. Clinical examination revealed a right iliac fossa mass. A plain abdominal radiograph was performed which suggested a developing small bowel obstruction and subsequent CT was performed by the ED staff which demonstrated a right-sided Spigelian hernia containing a loop of dilated bowel (figures 2 and 3). C reactive protein level was 5 (normal range <5 mg/L) but blood tests were otherwise within normal limits. The patient was then referred to the acute general surgery service. The hernia was reducible and the patient was booked for elective surgery due to limited emergency operating theatre capacity at our rural hospital. She was prescribed an abdominal binder. Prior to elective surgery, the patient presented twice more to the ED with pain related to her hernia. Repeated CT scan showed no evidence of obstruction.

Figure 2.

CT showing right-sided Spigelian hernia with small bowel showing signs of obstruction.

Figure 3.

Anatomy of anterior abdominal wall with location of Spigelian hernia from axial perspective. (Original author NRL).

Differential diagnosis

Spigelian hernias can be difficult to diagnose if the hernial contents are interparietal in position as there may be no clinically apparent mass on inspection or palpation of the abdomen. Presenting symptoms can be variable and can range from a palpable mass or pain in the abdominal wall to features related to incarceration or strangulation of hernial contents.³ In addition to this, there is a wide differential diagnosis for lower abdominal mass with pain and a non-comprehensive list of examples is given below (table 1). Spigelian hernia is a rare cause of this presentation.

Table 1.

Differential diagnosis for right lower abdominal pain and mass

Gastrointestinal	Gynaecological	Urological	Miscellaneous
Appendiceal abscess or tumour	Ovarian cyst	Ectopic kidney	Amoebiasis
Caecal tumour	Ovarian tumour	Transplanted kidney	Psoas abscess
Crohn’s disease	Uterine fibroid	Bladder tumour	Iliac lymphadenopathy
Carcinoid tumour	Ectopic pregnancy	Ectopic testis	Incisional hernia
Diverticular abscess
Meckel’s diverticulum

In the absence of clinically diagnostic features for a hernia, the diagnosis can be made with radiological investigations or laparoscopy.⁴ Clinical examination alone is only up to 50% sensitive for the diagnosis of Spigelian hernia,^{8 9} and cross-sectional imaging is approximately 70% sensitive.¹⁰ In our case, the left-sided hernia was only identified at the time of laparoscopy and was not apparent on any of the preoperative radiology studies.

Treatment

The patient was admitted for elective laparoscopic intraperitoneal repair of the right-sided Spigelian hernia. Intraoperatively, the patient was incidentally noted to have an additional left-sided Spigelian hernia. This left-sided hernia was not apparent in the preoperative imaging studies. Both hernias were repaired via the same laparoscopic intraperitoneal mesh technique.

The patient was operated on under general anaesthetic in the supine position. The surgeon and assistant worked on the left side of the patient, and crossed over to repair the contralateral hernia. Pneumoperitoneum to 15 mm Hg was established and two ports were inserted using an open technique. A 30⁰ laparoscope was inserted through a 12 mm supraumbilical balloon-tipped port. A 10 mm trocar was placed in the right upper quadrant, and a 5 mm trocar placed in the left upper quadrant (figure 4).

Figure 4.

Port positioning for surgical repair.

The contents of the right Spigelian hernia, including the appendix and caecal pole, were reduced into the abdominal cavity and the defect closed with a non-absorbable V-Loc suture. The appendix was healthy and was not removed (figures 5–7). The left-sided Spigelian hernia was empty at the time of surgery, and the defect was also closed with a non-absorbable V-Loc suture (figure 8).

Figure 5.

(A) Right Spigelian hernia containing appendix and caecal pole; (B) hernia defect after reduction of bowel.

Figure 6.

(A) Defect closed with V-Loc suture; (B) mesh repair of right-sided hernia.

Figure 7.

Open and laparoscopic surgical approaches to Spigelian hernia repair. (Original author NRL).

Figure 8.

(A) Left-sided hernia defect; (B) mesh repair of left-sided hernia.

Intraperitoneal Symbotex Composite Mesh 9 cm was then used to cover the repaired defects bilaterally and secured using AbsorbaTack fixation (figures 5–9) in a ‘double-crown’ fashion for both meshes. The mesh had been maintained in position for tacking with transfascial prolene sutures. Minor bleeding was noted from the area of mesh coverage on the right side. No other complications were observed during the operation.

Figure 9.

Anatomy of abdominal wall after transperitoneal on-lay mesh repair. (Original author NRL).

Outcome and follow-up

The patient’s postoperative recovery was notable for ongoing right lower quadrant pain. A follow-up CT scan of the abdomen was performed to investigate the cause of this persistent pain and ensure no failure of the repair or major complication had occurred. The scan revealed a small haematoma at the right-sided operative site that required no further intervention, and urinary retention which was managed with indwelling urinary catheter. Urinary catheter was removed by district nursing services in the community after discharge. The patient was discharged at postoperative day 5 with no further ongoing symptoms. Clinical review at 8 months postsurgery revealed no evidence of recurrence and the patient had returned to normal daily activities.

Discussion

First described in 1764, Spigelian hernias are rare protrusions of preperitoneal fat, peritoneal hernia sac or organ through a defect in the aponeurosis between the lateral edge of the rectus abdominis muscle and the semilunar line. Incidence has been reported as ranging from 0.12% to 2% of all abdominal wall hernias.^1–5

The risk of incarceration and strangulation of Spigelian hernia contents is significant, possibly due to the sharp fascial margins around a typically small hernial defect.^{4–6 11} Due to the high risk of complications related to these types of hernia, urgent surgical repair is generally advised. In our case, this option was not available due to limited operating theatre availability at our rural facility.

Spigelian hernias have historically been repaired via an open approach, but since the first described laparoscopic approach to Spigelian hernia repair was reported in 1992¹² a variety of different laparoscopic techniques have been described. The initial reports of laparoscopic repairs described using sutures to close the defect,¹² however, the use of mesh has since become routine and can be placed in an intraperitoneal position or in an extraperitoneal position by using either a transabdominal preperitoneal approach or a totally extraperitoneal approach.^{3 13} We elected to perform a transabdominal intraperitoneal repair (intraperitoneal mesh placement) in this case as it allowed visualisation of the whole abdominal wall thus identifying the occult contralateral defect, has significant cost benefits when compared with the totally extraperitoneal approach, and is technically the simplest to perform.¹⁴

The most common postoperative complications encountered in this surgery are seroma, haematoma and nerve entrapment (table 2).¹⁴ Haematoma is commonly due to inadvertent placement of securing tacks for the mesh repair, as in our case, and the use of fibrin sealant to reduce this risk has been suggested.¹⁵ Urinary retention is a fairly common postoperative occurrence with several possible causes including anaesthesia, medications, pain and the physiological changes of surgery. Our patient’s discharge was delayed by the above complications in addition to her advanced age and residential circumstances.

Table 2.

Comparison of open and laparoscopic approaches to Spigelian hernia repair

Surgical approach	Indications	Technique	Recurrence	Morbidity	Mesh choice
Open16	Emergency surgery Need for resection of hernia contents/viscus incarceration Large defect/contents Patient not suitable for general anaesthetic	On-lay mesh Sublay mesh	0%	18%	Polypropylene Parietex composite
Laparoscopic17	Elective surgery Small defects Non-diagnostic imaging	Intraperitoneal mesh placement	0%	2.3%	Composite Symbotex

The development of laparoscopic repair techniques has resulted in reported recurrence rates as low as 2.5% at short-term follow-up,¹⁴ and in the absence of clinically or radiologically complicating features, such as necrosis of the hernial contents, is the favoured approach to repair.¹² A comparison of the laparoscopic approach used in this case and a traditional open approach is given below (table 2).^{16 17} Data on long-term recurrence rates are sparse, but is reported as <5% in the published literature.¹⁸ Additional benefits of the laparoscopic approach include the ability to directly assess for additional defects that may be radiologically and clinically occult, and other possible abnormalities.

Learning points.

• Spigelian hernia is a rare cause for lower abdominal pain and mass.

• Early repair of Spigelian hernias is recommended due to their high risk of incarceration and strangulation.

• Cross-sectional imaging may not identify small uncomplicated Spigelian hernias.

• The laparoscopic approach to repair is associated with low rates of short-term recurrence and has additional diagnostic benefits over an open approach.

Ethics statements

Patient consent for publication

Consent obtained directly from patient(s).