Cord structure within an inguinal hernia: could the ureter be involved?

Summary

Inguinal hernias are commonly encountered and are primarily managed by surgeons; however, it is unusual for retroperitoneal structures, such as the ureter, to herniate into it. More importantly, hernias containing ureters are not usually identified preoperatively unless specific imaging was ordered prior, as they are generally asymptomatic. This poses a risk to the patient as unidentified structures can be mistakenly injured during the surgery. We describe a case of a man in his 60s, who presented with a large left-sided indirect inguinoscrotal hernia. Intraoperatively, a large amount of irreducible retroperitoneal fat was encountered in addition to a cord-like structure, which was discovered to be the left ureter after reviewing imaging intraoperatively. Initially, the hernia repair was done robotically, but it was converted to open repair due to its irreducibility and the potential risk imposed on the ureter. Additionally, we discuss the aetiology and common presentations of this kind of hernia.

Background

Inguinal hernias are a type of groin hernia described as the protrusion of abdominal contents, such as bowel or omentum, through a weakening in Hesselbach’s triangle or a congenital defect.¹ Most commonly, an inguinal hernia contains omentum and small intestine, but rarely, it can also contain structures such as the appendix.² According to one study, up to one-third of hernias are asymptomatic and even so, many patients opt for surgical fixation as the hernia can be uncomfortable and can subsequently impair some daily activities, especially for people who are athletic or conduct vigorous exercise.³ Surgery is recommended for patients with symptomatic inguinal hernias; however, surgery is an absolute and emergent indication for a hernia when it is incarcerated or, even worse, strangulated. Inguinal hernias, which are subtypes of groin hernias, can be direct or indirect, with the latter being the most common type in both men and women.¹ Very rarely, retroperitoneal structures, such as urological organs, can herniate and form what is called a sliding hernia.^{4 5} This can present with or without lower urinary tract symptoms such as obstructive uropathy and hydronephrosis.⁶ What is even rarer is a ureter being herniated along with an inguinal hernia, with only a few cases reported in the literature.^{7 8}

Case presentation

A male patient in his 60s, presented to the outpatient surgery clinic with a left-sided inguinoscrotal swelling. The swelling was noted by the patient around 1 year and a half ago and has been progressively increasing in size ever since. The patient reported that the swelling was not painful but caused a dull discomfort. The bulge was more apparent with vigorous exercise and when lifting heavy objects. Review of systems was negative for weight loss, fever, nausea, vomiting or change in bowel habits and negative for any lower urinary tract symptoms. Medical history was positive for primary hypertension, which was diagnosed 3 years ago. He had transcatheter aortic valve implantation 6 months prior to presenting and had a follow-up colonoscopy 2 months prior to presenting. The colonoscopy showed malignant polyps, which were excised by endoscopic mucosal resection. He was only on a daily 2.5 mg tablet of amlodipine for his hypertension, which was well-controlled. Social history revealed that he is a non-smoker, non-drinker, physically active and resides with his family.

Vital signs were all within normal range. His body mass index (BMI) was 32.3 kg/m², which is classified as class I obesity. Physical examination revealed a soft, non-tender, fatty abdomen with no hepatosplenomegaly. A focused examination of the groin showed a large left-sided bulge above the inguinal ligament, which extended towards his scrotum. No bulge was noted on the right side or in the femoral region. Head raise and cough impulse enhanced the bulge. The swelling was partially reducible, non-tender and soft in consistency. It was not possible to conduct the ring occlusion test due to partial reduction of the swelling only. Finally, the swelling was not transilluminant when light was shone through it.

At this point, the top differential diagnoses were unilateral inguinal hernia as the clinical history and physical examination findings were pointing towards it. Lipoma of the spermatic cord was another differential diagnosis as it is typically soft, non-tender, partially reducible and does not transilluminate with light, which matched the findings in our patient. While the patient presented with clinical symptoms and physical findings which were classical of an inguinal hernia, It was also imperative to rule out a testicular tumour, given the significant implication of missing such a diagnosis. Hence, an ultrasound imaging of the abdomen and pelvis was ordered.

Investigations

Ultrasound imaging of the abdomen and pelvis was performed at another facility prior to presenting to our outpatient clinic, which revealed a fat-containing left indirect inguinal hernia extending into the left scrotal sac. No hernia was appreciated in the right groin, nor was a primary malignancy identified. The physical examination findings, as well as imaging, were consistent with a left-sided incarcerated inguinal hernia.

Preoperative laboratory investigations included full blood count (FBC), creatinine and glomerular filtration rate (GFR). All of the mentioned tests were within normal range.

Treatment

The patient was planned for a robotic unilateral inguinal hernia repair under general anaesthesia. The medications that were given intraoperatively were intravenous Ringer’s lactate and intravenous cefazolin.

A urethral Foley catheter was placed, and the patient was positioned at 15° Trendelenburg. Three ports were used for this surgery: an umbilical endoscopic port and two right and left lateral ports. Pneumoperitoneum was obtained through a Veress needle.

During the surgery, it was noted that there was a very large amount of fat, which was not reducible. After trying to reduce the fat for a while, a cord structure measuring around 8 mm in diameter was identified in the retroperitoneal region and after stimulating the structure with forceps, the peristaltic movement was noted as shown in the online supplemental video. The surgeons reviewed the imaging of the patient intraoperatively and noted that there was a recent abdominal and pelvic CT imaging with intravenous contrast ordered by the patient’s gastroenterologist to follow-up after his recent colonoscopy. The imaging results showed no colonic abnormalities but showed fullness of the left renal pelvis and left ureter. Additionally, it showed that the distal left ureter extended into the left-sided inguinal hernia before coursing its way back toward the urinary bladder. Figure 1 shows the path of the left ureter as it approaches the hernial sac in the axial and sagittal views. It was concluded that the cord-like structure encountered was the left ureter, and due to the irreducibility of the fat and the risk posed in terms of potential injury to the ureter, the surgery was converted to an open inguinal hernia repair. A left-sided inguinal incision was made, and the hernial sac was identified. The ureter, as well as the retroperitoneal fat, was dissected away from the hernial sac and reduced. The surgeon decided to use a mixed repair method in this case, and he did so by reinforcing the posterior wall of the inguinal canal by suturing the hernial sac as is done in the Bassini repair method. Additionally, he added a polypropylene mesh to reinforce the floor of the inguinal canal, as is done in Liechtenstein’s method of repair.

Figure 1. CT imaging with intravenous contrast images showing both axial and sagittal views, with the red arrow pointing at the left ureter. The leftmost image shows the dilated left ureter in the pelvis, and the middle image shows the ureter being dragged with the hernial sac, but not protruding into it. The rightmost image shows the left ureter coursing in the pelvis toward the hernial sac.

Outcome and follow-up

The final diagnosis of the groin swelling was a large inguinoscrotal, indirect sliding hernia along with herniation of the left ureter. The hernial sac contained retroperitoneal fat only. The left ureter was included in the hernia but was not a part of the sac.

Postoperatively, the patient was vitally stable and fully alert. The catheter was removed a couple of hours after the surgery as the patient was able to void freely but had no bowel movements. He reported mild pain in the surgical sites but had no other issues. On examination, the abdomen was soft and not distended. Bowel sounds were audible and no scrotal swelling was seen. On the first day postoperatively, the patient continued to do well, was vitally stable and was ready for discharge. The patient was asked to avoid driving, heavy lifting, or vigorous exercise for 2 weeks. In terms of laboratory investigations, urinalysis, FBC, creatinine and GFR were all measured prior to discharge and were all within normal range.

On follow-up, 1 week after the surgery, the patient continued to do well and was starting to return to daily activities. The surgical site was clean, and there was no pain at the surgical sites.

Discussion

This patient was found to have a ureteral inguinal hernia in the presence of some risk factors, including having a BMI of more than 30 and being male. The ureter was discovered incidentally during the surgery due to its size and characteristic peristaltic waves, and it was confirmed in a CT scan intraoperatively, which prompted conversion to open hernia repair with mesh from the robotic approach. It is important to keep in mind that while the ureter was herniating, it did not form a part of the hernial sac, which contained only retroperitoneal fat.

Ureteral involvement in inguinal hernias is rare and is usually discovered intraoperatively.⁶ Ureteroinguinal hernias (also called ureteral inguinal hernias), which extend into the scrotum, are a rare entity that can be encountered by general surgeons.⁸ Ureter herniation is associated with inguinal hernias twice as much as femoral hernias. They are usually indirect rather than direct and often tend to present on the right side.⁶ Figure 2 shows a simplified illustration of the ureter herniating into the scrotum, as was seen in our patient.

Figure 2. A simple illustration of the ureter herniating into the scrotum along with fat, from the retroperitoneum, as was seen in our patient. Author(s): Asma Alshehhi.

There are two main anatomical subtypes of ureteroinguinal hernias: paraperitoneal and extraperitoneal. In the paraperitoneal type, a segment of the ureter runs parallel to the peritoneal sac and is adherent to the posterior peritoneum. This type of hernia is categorised as sliding, which is likely attributed to the force exerted by underlying structures or adhesions binding the ureter to the posterior peritoneum. In comparison to the paraperitoneal type, the extraperitoneal type, as was seen in this patient, is thought to be either caused by postoperative anatomical changes to previous surgery or as a result of a congenital defect during embryonic development, which leads to the fusion of the ureter with the genitoinguinal ligament. This fusion is hypothesised to be the result of the incomplete separation of the ureteric bud and the Wolffian duct.⁷ In these types of hernias, which are predominantly indirect, there is no peritoneal sac and usually presents with copious amounts of retroperitoneal fat, which slides and pulls the ureter with it by gravity.⁹ Symptoms associated with ureteroinguinal hernias include obstructive uropathy, hydronephrosis and rarely renal failure, but many patients can be completely asymptomatic, as was the case for our patient.^{10 11} Additionally, severe flank pain and dysuria have been reported in a patient with his right ureter being the only structure forming a right inguinal hernia.¹² Risk factors for such hernias include male gender, old age, especially during the fifth decade and obesity. Additionally, patients who have undergone kidney transplants and those with renal anomalies face an elevated risk, potentially due to the anterior positioning of the transplanted ureter within the space of Retzius. Hence, it is rare for patients with native kidneys to present with such hernias.^{6 12} Our patient was at higher risk, considering he was a male and had class I obesity.

There are no formal guidelines on the management of ureteral inguinal hernias; however, the closest entity that has formal guidelines would be a complicated or large inguinoscrotal hernia. According to most recent clinical guidelines, surgical intervention is the main approach to managing large inguinoscrotal hernias.¹³ Early surgical management has been associated with a lesser likelihood of fatal complications. Preoperatively, imaging with CT or MRI, particularly a review of the excretory phase of the CT or MRI urogram, is only indicated for large irreducible hernias to identify the contents of these hernias, aiding the choice of preoperative management as well as the surgical approach.^{14 15} Additionally, preoperative laboratory investigations such as urinalysis, creatinine and GFR are indicated if there is a high suspicion or confirmed urological organ involvement.¹⁵

In planning the surgery, after obtaining imaging results, the surgeon should decide whether to conduct an open, laparoscopic or robotic surgery, depending on the findings, their expertise and the most up-to-date guidelines. Moreover, in terms of the preferred surgical intervention, open mesh repair is the recommended approach for large or irreducible inguinoscrotal hernias.^{13 14} There have been multiple reports of inguinal hernias with ureteral involvement being successfully repaired via laparoscopic^{16 17} and robotic-assisted laparoscopic repair.^{18 19} Prior to laparoscopic or robotic repair, ureteral visualisation aids in avoiding injury to the ureter. In laparoscopic repair, stenting has been used to aid the identification of the ureter intraoperatively,^{16 17} and indocyanine green dye has been used to highlight the ureters in robotic surgery.^{18 19} However, the surgeon should keep in mind that the threshold for conversion to open repair in these cases is low, which must also be communicated to patients. Figure 3 shows a proposed flowchart for patients with suspected ureteral inguinal hernia or for a patient who presents with a massive inguinoscrotal hernia.

Figure 3. A proposed flowchart for the workup of a patient with an inguinal hernia and suspicion of ureteric involvement. *The choice of the type of surgery depends on the expertise of the surgeon, but the threshold for conversion to an open procedure should be low in the presence of urological organ involvement due to the increased risk of injury and potential complications. Author(s): Fatemeh Akbarpoor, Faisel Ikram. IV, intravenous.

It is essential to take care with such hernias to avoid injury to the ureter during herniorrhaphy or hernioplasty, especially for the novice surgeon. Surgeons should be cautious when seeing large amounts of fat in the hernia, as blunt dissection could result in direct injury to the ureter. Additionally, reviewing any imaging ordered preoperatively is essential to aid in planning the surgical procedure and avoid complications. In this case, the preoperative CT of the patient was not reviewed by the surgeon before the surgery as it was ordered for another purpose. Ordering and reviewing preoperative CT scans can help guide the surgeon’s technique in large, incarcerated hernias that may contain retroperitoneal structures.

Learning points.

• A ureter being found in an inguinal hernia is a rare occurrence and its usually associated with large indirect hernias with copious amounts of fat.

• This case underscores the importance of conducting a thorough work-up including any laboratory investigations and imaging prior to performing a surgery, even a routine one such as inguinal hernia repair.

• Additionally, it is important to review imaging prior to surgery, even if ordered by colleagues from other specialties, since imaging can guide better planning of the surgery.

• If there is a large inguinoscrotal hernia, coupled with lower urinary tract symptoms, there might be urological organ involvement hence ordering imaging such as CT urogram will aid in diagnosis and surgical planning.