Abdominal Wall Hernias: A Previously Unrecognized Risk During Abdominal Wall Blocks
Introduction: Abdominal wall plane blocks have been shown to have a statistically significant analgesic benefit and opioid sparing effect in adults undergoing abdominal surgeries. These blocks are becoming widespread and often utilized interventions to assist with the multimodal approach to analgesia for hernia surgeries. This case series aims at educating fellow anesthesia providers of an important consideration while performing transversus abdominis plane (TAP) and rectus sheath blocks in patients with abdominal wall hernias.
The prevalence of abdominal wall hernias in the United States is approximately 1.5%. Parastomal hernias occur in approximately 38% of all parastomas created. Some of these hernias may be externally apparent, while others are difficult to visualize.
Results/Case Report: Figure 1 shows a 40-year-old female with a spigelian hernia lying between the external and internal oblique muscles. Figure 2 shows a 54-year-old female with a parastomal hernia extending over her oblique muscles.
Discussion: If a TAP block were performed in the above patients with either the blind “two pop” technique or a less attentive provider utilizing ultrasound, there would be a risk of puncturing bowel with the advancing needle. This can lead to several sequelae including bleeding into and around the bowel as well as infection secondary to the tracking of intestinal contents into surrounding tissue.
A regionalist may minimize the risk of these complications by carefully analyzing the tissue above and between the abdominal wall muscles, looking for signs of a discernible lumen, peristalsis, and compressibility. If uncertain, asking the patient to perform a valsalva maneuver may increase the amount of herniated bowel, thus making the diagnosis easier.
By being aware this pathology can occur, we can become more informed clinicians, thereby providing safer care for our patients. If a practitioner wants to anesthetize the same nerves without the risk of bowel puncture in this patient population, a Quadratus Lumborum block may be considered as an alternative to the TAP block.