Innervation of the Anterior Abdominal Wall

The anterior abdominal wall is innervated by an intricate network of intercostal nerves (T7 through T12), the iliohypogastric nerve, and the ilioinguinal nerve (L1), which extend from the lower spine horizontally across the abdominal wall toward the midline (►Fig. 2). These nerves contribute to cutaneous sensation and to thermal and pain sensitivity (►Table 1).

Fig. 2 - Cutaneous sensory nerves of the abdominal wall and groin and innervated areas.

Fig. 2 - Cutaneous sensory nerves of the abdominal wall and groin and innervated areas.

Table 1 - Innervation of the abdominal wall

Studies on Cutaneous Sensitivity Recovery

Studies conducted by Farah et al.⁵ aimed at evaluating sensory changes in the abdominal skin following abdominoplasty, using tests that simulated tactile, thermal, and pain sensitivity in common scenarios. The abdominal region was divided into 12 areas (►Fig. 3). Their findings revealed that the most significant decrease in sensitivity occurred in area 8, which also showed diminished pressure sensitivity. While area 11 exhibited a statistically significant reduction in hot and cold temperature sensitivity, the changes were less pronounced than those observed in area 8. These results align with anatomical considerations, as the anterior cutaneous nerves—which are responsible for supplying the abdominal wall—are severed during the undermining of the abdominal flap, particularly affecting the hypogastric region (area 8). This area becomes the distal-most point of sensitive nerve connections after surgery, as the extensive incision and undermining isolate it from adjacent nerve supply. Conversely, the suprapubic region (area 11) likely experiences sensory loss due to traction rather than nerve disruption, as undermining is not typically performed in this region. These patterns of sensory change emphasize the distinct mechanisms influencing nerve injury in different abdominal areas. Supporting these findings, research on skin flaps suggests that sensory recovery follows a predictable sequence, with pain returning first, followed by tactile, and, finally, thermal sensitivity. Understanding these dynamics is crucial for surgeons aiming at minimizing sensory loss and optimizing postoperative outcomes in abdominoplasty patients.

Fig. 3 - Abdomen divided into 12 areas: 1–right hypochondrium; 2–epigastric; 3–left hypochondrium; 4–right lumbar; 5–supraumbilical; 6–left lumbar; 7–right iliac; 8–infraumbilical; 9–left iliac; 10–right infraincisional; 11–midline infraincisional; and 12–left infraincisional.

Fig. 3 - Abdomen divided into 12 areas: 1–right hypochondrium; 2–epigastric; 3–left hypochondrium; 4–right lumbar; 5–supraumbilical; 6–left lumbar; 7–right iliac; 8–infraumbilical; 9–left iliac; 10–right infraincisional; 11–midline infraincisional; and 12–left infraincisional.

While most patients experience partial sensation recovery within months after surgery, some may have long-term hypoesthesia or anesthesia, leaving the area vulnerable to thermal trauma, especially if they use heating devices like hot-water bottles.

The scientific literature suggests that postabdominoplasty sensory loss follows a variable recovery pattern. While most patients experience partial sensory recovery within 6 to 12 months,⁶ full restoration is not guaranteed. Studies⁷ indicate that nerve damage can lead to long-lasting neuropathies, with thermal sensitivity being one of the most challenging sensations to regain. In fact, after a period in which subjects perceive no stimuli at the flap, pain sensation returns first, followed by tactile, and, finally, thermal sensibility.

Literature Review on Postabdominoplasty Burns

Burn injuries in patients following abdominoplasty, particularly from hot-water bottles or other heat sources, have only been reported in a few other cases.⁸ These incidents highlight the vulnerability of postoperative patients to thermal injuries due to compromised cutaneous sensation, particularly in the infraumbilical region.

In 2023, Alokaili et al.⁹ reported the case of a 26-year-old healthy female post-abdominoplasty patient who sustained an incidental contact burn injury caused by the use of a common home remedy for menstrual pain. In this instance, the burn healed via secondary intention.

In early 2024, Syras et al.¹⁰ documented 3 cases of third-degree contact burns at the infraumbilical level, resulting from the use of a hot-water bottle shortly after abdominoplasty. These injuries led to significant esthetic sequelae.

Both studies recommend counseling patients regarding caution or the avoidance of such practices following abdominoplasty, particularly given the potentially-disfiguring complications associated with thermal injuries.

Abdominoplasty inevitably leads to temporary or permanent reductions in cutaneous sensitivity in the infraumbilical region, with significant implications for patient safety. The risk of burns from the application of hot-water bottles is high and requires careful preventative management, including detailed preoperative education and continuous postoperative monitoring. A thorough knowledge of anatomy and anatomical variations helps prevent injuries, butahigh index ofsuspicion should be maintained to accurately diagnose nerve injuries in patients presenting with chronic postoperative pain or apparent nerve dysfunction. Given the temporary or permanent hypoanesthesia of the infraumbilical region following abdominoplasty, the literature consistently emphasizes the importance of patient education regarding the altered sensory landscape postoperatively, particularly in relation to heat-application risks. Ensuring patients understand the risks and adopt preventative measures can significantly reduce the likelihood of thermal injuries, enhancing postoperative recovery and overall patient experience.