SH can develop following various types of surgical procedures including median sternotomy, midline epigastric laparotomy, or chevron incisions [8]. These procedures are often employed for cardiac or upper abdominal surgeries, making SH a notable complication in these contexts.

Several patient-related risk factors are frequently associated with the development of SH. These include obesity, male sex, advanced age, surgical site infections (both superficial and deep), left-sided heart failure, low cardiac output syndrome, long incisions, reoperations, heart transplant surgery, immunosuppression, as well as conditions like diabetes mellitus (DM), smoking, chronic obstructive pulmonary disease (COPD), history of other hernias, and postoperative bleeding that requires early transfusion [1, 3, 6, 9–11]. Notably, only one single-center study by Kim et al [6] has identified female gender as a risk factor for SH formation, which contrasts with the general male predominance found in the majority of the literature. Weight loss for obese patients and avoidance of reoperation when possible may be considered [12].

Technical factors also play a crucial role in SH development. Inadequate incision techniques, improper closure methods, and the use of absorbable sutures, are associated with an increased likelihood of hernia formation. These technical issues can contribute to weak abdominal wall closure, leading to the formation of hernias over time.

Barner [13] proposed a modification of median sternotomy to reduce the occurrence of SH. This modified approach involved using a shorter incision that stopped before the xiphoid process and angled off midline, towards the left xiphoid-costal angle. This technique provided adequate exposure for the procedure while avoiding disruption of the linea alba, which is a key structure in abdominal wall integrity. Notably, none of the 2,500 patients who underwent surgery with this technique developed SH. However, it is important to exercise caution during these approach to avoid injury to the left superior epigastric artery, which supplies vital blood flow to the abdominal wall.

Davidson [3, 12, 14] further suggested using non-absorbable sutures to close the linea alba. This technique ensures a more durable abdominal wall closure, potentially reducing the risk of hernia development post-surgery.

Wound infection and immunosuppression have been recognized as significant predisposing factors for SH recurrence after surgical repair [1, 9]. Effective and early diagnosis and management of wound infections are critical to preventing both the development of SH and its recurrence [9].

Most SH are small and asymptomatic and as a result they remain undiagnosed, as only symptomatic patients seek medical attention, indicating that the real incidence is underestimated [5]. Specifically, the percentage of symptomatic SH varies widely, ranging from 35% to 100% [3, 5]. These hernias usually develop within the first 3–4 years postoperatively [8]. Epigastric pain, bulging, nausea, vomiting are some of the symptoms reported [14, 15]. It is speculated that the underlying liver prevents bowel incarceration within the hernia defect [15, 16]. Patients with symptomatic SH are generally treated electively [2]. However, urgent surgical intervention due to incarceration has been also reported in the literature [2]. Liver incarceration has also been described [17]. These cases highlight the potential for SH to cause significant complications if left untreated or undiagnosed for too long.

Physical examination in combination with ultrasound or computed tomography (CT) are necessary for the confirmation of the diagnosis [15]. Computed tomography (CT) of the chest and abdomen is essential for assessing the extent of the hernia [8]. Dynamic CT with Valsalva manoeuvre may also be useful [11]. CT imaging can provide detailed information about the hernia’s size, which can vary significantly, with some hernias reaching up to 16 cm in the longitudinal axis [18], while the average size typically ranges from 2 to 15 cm [8]. This imaging helps to plan the appropriate surgical approach and anticipate any challenges that might arise during repair.

Preoperative assessment should include a comprehensive cardiac workup, as many of the patients suffer from an underlying cardiac condition [8]. This evaluation ensures that the surgical team is fully informed about the patient’s cardiac status, which is crucial for optimizing the perioperative management and minimizing potential complications.

Overall, seventeen articles were identified with 442 patients in total. 320 patients underwent open repair, while in 122 patients laparoscopic approach was achieved. The majority of the studies are single center retrospective studies. Only one multicenter study with a larger sample was identified. Two studies were prospective, while only three studies provided comparative outcomes between open and laparoscopic approach. Case reports are also included. A brief summary of the literature is illustrated in Table 1.

Recurrence rates following SH repair have been reported to range from 24% to 44% [6], highlighting the challenging nature of the procedure. The high rates of recurrence following primary suture repairs, which can range from 43% to 80% [5, 9], underscored the need for improved techniques and materials. This led to the adoption of polypropylene mesh for open surgical repair, a practice first introduced by Cohen and Starling in the 1980s. They used a preperitoneal approach, entering the peritoneal cavity only when necessary to free adhesions, which helped minimize surgical trauma [14]. Davidson and Bailey [12] described the application of a double door flap as a modified Well’s procedure, for the repair of large subxiphoid hernias more than 10 cm, with zero recurrence rates after three and a half years of follow up, however this technique was applied in only three patients. The introduction of a permanent mesh significantly reduced the recurrence rates. Studies have reported recurrence rates between 0% and 32% wish mesh repair [5, 9], demonstrating a clear improvement compared to suture-only methods.

There are several approaches for mesh placement in SH repair. The main techniques include onlay [10, 18], sublay [10, 15, 16], preperitoneal [22], rectorectus [19], and intraperitoneal onlay mesh (IPOM) placements. A variety of mesh placement approaches is noticed even within the same studies, while not all of them provide sufficient information. In addition, different kind of meshes and sutures were used, which makes it difficult to compare and reach safe conclusions. Τhe onlay approach is the simplest and the most reproducible technique, but it is associated with higher rates of recurrence, seroma formation, and infection [5]. The rectorectus approach usually allows adequate mesh overlap and is considered a reliable approach for achieving a stable repair [23]. Intraperitoneal onlay mesh placement was applied in all the laparoscopic procedures, as shown in Table 1. In addition, Awad et al [7] adjusted the Rives-Stoppa-Wantz repair to the SH repair by detaching the posterior sheath from its insertion to the posterior aspect of the xiphoid, and placing the subxiphoid part of the mesh intraperitoneal. Care should be given to avoid encircling the ribs with the mesh, as the costal perichondrium is very well innervated, and such placement can lead to persistent pain postoperatively [5].

Although the closure of the SH defect is important, large defects or increased tension make it particularly challenging. The Clotteau method involves multiple incisions in the external oblique aponeurosis to allow relaxation and approximation of the linea alba in the midline in combination with mesh placement [5, 18]. Multiple vertical relaxing incisions on the anterior rectus sheath were applied by Bouillot et al [19] and de Mesquita et al [18], in combination with rectorectus and onlay mesh placement respectively, with no recurrences reported in the follow up. When laparoscopic approach is used, the hernia defect is usually not sutured. Ghanem et al [8] applied incisions in the posterior rectus sheath laparoscopically, for the closure of the abdominal wall defect when possible. Otherwise, intraperitoneal onlay bridging was preferred for larger defects [8].

Another method suggested in order to overcome the tension related to the hernia wall closure, is the application of two meshes. Tatay et al [11] described a double mesh technique, with one mesh applied preperitoneal and one supra-aponeurotic, to avoid any tension. This technique was performed in 35 patients, 10 of which following heart procedure, with no recurrence rates. Abello et al [22] applied the same adjusted double mesh technique in 20 patients and the outcomes were compared to the conventional preperitoneal mesh placement performed in 22 patients in terms of an observational non randomized study. No statistically significant differences in hernia recurrence was found between the two groups (P = 0.288), suggesting there is not enough evidence to support the double mesh technique.

In 2001, Landau et al [2] described the first laparoscopic repair of post-sternotomy subxiphoid epigastric hernia. The laparoscopic approach allows better visualization of the hernia defect, minimizes tissue trauma, avoids previously infected sternal wounds, and reduces operative time [9, 15]. For a laparoscopic repair, adhesiolysis and takedown of the falciform ligament up to the hepatic veins are mandatory steps to fully expose the hernia defect and ensure that there is adequate mesh overlap (approximately 5 cm) [5, 8, 10, 23]. A wider overlap of 7–10 cm laterally for larger defects has been suggested by Ghanem et al [8]. In case no sutures are placed above the costal margin, an additional overlap of 8 cm superiorly has been proposed, to make sure that the liver holds the mesh during desufflation of the peritoneal cavity [24].

In the repair of ventral hernias, proper mesh fixation with sutures and tacks is crucial to prevent recurrence and complications, due to possible dislocation of the mesh [17, 20]. However, in terms of a laparoscopic subxiphoid hernia repair, neither sutures nor tacks are placed in the cephalad part, above the costal margin [20]. When tacks are used, they should be placed at or below the costal margin, and definitely not above it, as they might cause chronic pain or pericardial injury resulting in complications such as pericarditis and cardiac tamponade [23, 25]. In fact, the mortality rate associated to pericardial or heart muscle injury after tack fixation can be as high as 48%, despite surgical intervention [24]. Instead, nonabsorbable intracorporeal sutures can be applied superficially to fix the mesh to the diaphragm and encourage scarring, with caution after grasping the diaphragm [8, 17, 18]. Some surgeons prefer not to fix the mesh above the costal margin at all, relying on the liver and stomach to secure the mesh in place [20]. The use of fibrin glue for the fixation of the mesh on the cranial side has been explored, but it has been associated with high recurrence rates [15, 24].

Mesh fixation using only tacks is not recommended, as they penetrate the mesh for only 2 mm [5]. Therefore, additional full-thickness sutures placed circumferentially every 3–6 cm have been suggested to ensure fixation especially when fascial closure is not achieved, always below the costal margin [5, 8]. For laparoscopic repair, a fascial closure device, such as Endoclose or Endoclinch, may be helpful [2, 8]. Hope and Hooks [23] suggested placing the most superior stitch right below the xiphoid or on the lateral side of the xiphoid. Finally, fixing the mesh laterally to the rectus muscles offers better mechanical stability and reduces the risk of injury to the epigastric vessels, which could result in a hematoma or require reoperation [26].

When intraperitoneal mesh is used, a dual-surface material is preferred, to avoid potential complications, such as adhesions and bowel fistula [2]. In this review, dual-surface mesh was used in all IPOMs, when relevant information was provided [2, 4, 10, 17, 20]. Regarding postoperative complications concerning abdominal viscera, only one small bowel obstruction requiring laparoscopical repair in the early postoperative period, was reported [2], while one patient developed ileus managed conservatively [20]. For open repair, non-absorbable meshes usually from polypropylene [10, 11, 14, 18] or polyester [19] are preferred. Only one study mentioned the application of partially absorbable meshes with no recurrence rates [15], while only one case with biological mesh placement in a heart transplant recipient is reported in the literature with a follow up period of 6 months [16].

Complications such as hematomas [18, 19], seromas [11], wound infection [9, 11], partial wound dehiscence [18], or other severe complications requiring reoperation [15], appear to be more frequent in the open repair, as seen in Table 1. However, no statistical significant difference was found in the study published by Albrecht et al [10], where the sample size was larger.

The recurrence rates may be further reduced with laparoscopic repair, with reported rates as low as 10% [2, 18], however there are not enough data to support the superiority of the laparoscopic approach. Only 3 comparative studies were identified in the literature. Mackey et al [9] reported 30% (3/10) recurrence in the laparoscopic and 33.3% (7/21) recurrence in the open group. Raakow et al. [15] reported higher recurrence rates in the laparoscopic group (p = 0, 031). However, the sample size was small, including 20 patients in the open, and 8 patients in the laparoscopic group, while the open group was associated with higher rates of lost follow-ups. In addition, the hernia defect was not primarily closed in the laparoscopic group. For these reasons, the increased recurrence rates after laparoscopic surgery as reported in this study should not be considered discouraging. On the other hand, Albrecht et al [10] in a multicenter study with 208 participants in total, found no statistical significant difference regarding recurrence rates (laparoscopic group 7.2 vs. open 2.2%; p = 0.072) after 1 year of follow up.

The use of an abdominal binder for the first 4–6 postoperative weeks has been proposed by Raakow et al. [15], beginning right after the end of the procedure. The role of drains in seroma prevention remains unknown [15].

Special consideration should be made in heart transplant recipients undergoing SH repair. These patients often require the expertise of a dedicated cardiac anesthesiologist to manage their complex cardiac status. Additionally, lower intraabdominal insufflation pressures are recommended, and continuous monitoring of cardiac function is essential [20]. A combination of general and epidural anesthesia is also suggested to enhance pain control and promote faster recovery [4]. For high-risk patients undergoing open repair, bilateral ultrasound-guided transverse abdominis plane (TAP) block has been proposed as an effective method for providing regional anesthesia. This technique avoids intubation and hemodynamic alterations during surgery [27]. It also prevents postoperative pulmonary complications, nausea, and achieves better analgesia, leading to earlier mobilization [27].