Keywords

1 Introduction

Most incisional hernias are classified according to the size of the hernia defect, in particular to their width [1,2,3] and not by the difficulties in reduction of the herniated content. However, some of them, 5% in our experience [4], cannot be restored into the abdominal cavity. These giant incisional hernias with loss of domain (IHLD) imply that a proportion of the abdominal content, 20% according to Kingsnorth [5], fills permanently the extraperitoneal hernia sac [6, 7], thereby leading to a “second abdominal cavity” [8] (Fig. 14.1).

Fig. 14.1
figure 1

Example of giant incisional hernias with loss of domain (IHLD), leading to a real “second abdominal cavity”

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Recently, a group of expert surgeons has proposed loss of intra-abdominal domain as a common criterion to define a complex ventral hernia [9] . In case of IHLD, the massive visceral protrusion presents a major therapeutic challenge due to the difficulty to restore the volume of the herniated content into the abdomen and complete closure of the abdominal wall myofascial layers [10, 11]. Further, IHLD development is associated with lateral wall shortening and oblique muscle atrophy with decreased extensibility and compliance [12]. The replacement of the viscera within an unyielding and stiff abdominal wall may compromise the perfusion of the intestines, elevate the diaphragm [13] and may lead to subsequent intra-abdominal hypertension [14] . This situation may induce acute pulmonary complications and even a postoperative abdominal compartment syndrome [15,16,17].

1.1 Preoperation Treatment Options

Several techniques have been described to increase the abdominal cavity volume [18], including tissue expanders, botulinum toxin, component separation techniques (CST) and progressive preoperative pneumoperitoneum (PPP).

The different component separation techniques (CST) are extensively reported and well described for the surgical treatment of IHLD [19,20,21,22,23,24,25,26,27,28] and are rapidly becoming the technique of choice in complex ventral hernia repair, even sometimes considered as a standard for the repair of all midline incisional hernias [25, 29,30,31]. The first technique described was anterior CST, reported by Ramirez et al. [32, 33]. In this technique, the external oblique muscle aponeurosis is sectioned near the semilunar line, allowing advancement of the composite flap of the ipsilateral rectus muscle medially to the midline. More recently, Novitsky et al. [19] described the transversus abdominis release (TAR). This technique consists in an extension of the Rives-Stoppa technique where the transversus abdominis muscle insertion is sectioned near the semilunar line, allowing the creation of a plane laterally between the transversus abdominis muscle and the transversalis fascia. The TAR, also called “perforator preserving CST” [29], is a safe alternative to the posterior component separation described by Carbonell et al. [20] where the lateral plane is created between the internal oblique and the transversus abdominis muscle, thus affecting the abdominal perforator nerves and vessels.

Anterior CST seems more able than the TAR to achieve the objective of closure of the midline since it allows an advancement of the rectus muscle medially up to 10 cm in length on both sides [32]. It has also been shown to increase the abdominal cavity volume by an average of 7% [13]. Of note, however, comparable outcomes of TAR and anterior CST have been reported in meta-analysis [30].

Nevertheless, anterior CST requires the lateral dissection of the subcutaneous space, leading to an increased risk devascularized skin flaps and impairment of the wound healing process with the subsequent risk of skin necrosis [24]. Further, both the anterior CST and TAR significantly alter the normal anatomy of the abdominal wall since these methods intentionally disrupt the integrity of the musculofascial components of the abdominal wall [13]. These factors may explain why CST is associated with a rate of wound complications as great as 26–42% and a recurrence rate up to 30% in large series [11, 19, 20, 34].

2 Progressive Preoperative Pneumoperitoneum (PPP)

First described in 1947 by Moreno [35], PPP represents an interesting alternative for surgical repair of IHLD without permanent alteration of the musculo-aponeurotic integrity of the abdominal wall [4]. It involves the progressive insufflation of the abdominal cavity. Prior to the surgical repair of IHLD. This is undertaken with the purpose of the complete reduction of the hernia content without division of any muscle or its associated aponeuroses, thus achieving a reduction of the post-operative complication rate [4, 18, 36, 37].

Contrary to CST, PPP involves a long preoperative preparation of the patients before IHLD repair, also called “Goni Moreno protocol”. Indeed, we think that the preparation of these patients, including careful pulmonary, cardiac and anesthesiologic evaluations, as well as appropriate skin preparation, is essential and should be, in fact, as crucial as the operation itself [4, 27, 36].

This technique has been used for a long time by specialized teams [38,39,40,41,42,43,44,45] but is still not extensively performed in the majority of hospitals. Nevertheless, specialized teams have reported good results with acceptable risk rate [4, 11, 36, 44, 46, 47]. Even if their series included limited number of patients [4, 11, 48], they have recently published objective data. However, no recommendation has been published until now about the indication of PPP, neither the precise protocol nor the method of repair.

2.1 Prior Evaluation of the Loss of Domain

The indication of PPP is usually based on clinical examination, ie, any incisional hernia that could not be reduced on physical exam [4, 44]. Nevertheless, it is sometimes difficult to clinically estimate the exact size of the incisional hernia, due to bowel adhesion or obesity [4]. Preoperative CT measurements of hernia defect sizes and abdominal wall thickness is mandatory for all complex incisional hernia [49]. In addition, in case of IHLD, preoperative CT-scan, with valsalva maneuver whenever possible, allows objective measures of the volume of the incisional hernia. Tanaka et al. [47] were the first team to report an objective method to calculate the exteriorized volume of the abdominal content on CT-scan. The hernia sac volume (VIH) and the abdominal cavity volume (VAC) were approximated by using their diameter within the three planes of space and using the mathematical formula of an ellipse (4/3 × π × r1 × r2 × r3), considering the shape of the two abdominal compartments as elliptic (Fig. 14.2). Using the Archimedes theory in the rat model, the efficiency of this method has been validated [50]. The exact VIH and VAC are now routinely calculated directly on CT-scan using volumetric software, as it is performed for hepatic volumetry (Fig. 14.3). The volume of the peritoneal cavity is calculated as the sum of VAC + VIH. The ratio of the volume of the hernia content was calculated according to the ratio VIH/(VAC + VIH), representing 45% on the specific example in Fig. 14.3.

Fig. 14.2
figure 2

Method to calculate VIH and VAC according to Tanaka on CT-scan (a, b) from a patient with median IHLD (c, d). VIH = 4/3 × π × a × b × c. VAC = 4/3 × π × A × B × C. (e) Result after PPP and surgery

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Fig. 14.3
figure 3

CT volumetric measurements before PPP (a, b: Axial CT slide; c, d: Sagittal CT slice) in a patient presenting with a median giant IHLD (i, j). The VIH was measured at 3820 mL. The VAC was measured at 4653 mL. The ratio of the exteriorized visceral volume was calculated at 45% in this patient before surgery. CT volumetric measurements after progressive preoperative pneumoperitoneum and before surgery (e, f: Axial CT slide; g, h: Sagittal CT slice). The VAC was measured at 6951 mL which represented a mean VAC increase of 49%. (k) Results 6 months after surgery

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2.2 Is There a Percentage of Herniated Volume from Which a PPP Is Indicated?

This exact determination is not clearly defined. Tanaka et al. [47] suggested that PPP should be performed when the ratio was at least 25%. Kingsnorth et al. [5] considered that a respiratory prehabilitation (smoking cessation, respiratory adaptation with intensive respiratory physiotherapy) should be performed in patients with a ratio of 15–20%. However, abdominal volumetry was not performed in the latter study. We consider that a IHLD with an exteriorized ratio of 20% should be prepared using PPP since recent prospective studies have shown that an exteriorized volume <20% of the entire peritoneal volume was predictive of a relative tension-free fascia closure and was associated with less postoperative pulmonary complications [9, 48, 51].

2.3 Objectives of the PPP

PPP has many potential and/or theoretical advantages [4, 18, 36, 37], including:

  • The progressive distension of the lateral abdominal wall muscle will enlarge the abdominal cavity and allow the complete reduction of the herniated content and subsequent ability to close the defect completely.

  • The PPP will cause progressive abdominal hypertension thereby resulting in diaphragmatic rehabilitation before surgery to improve ventilatory function. In other words, this can act as a pre-operative respiratory tolerance test. Some authors argue that PPP should be contraindicated in patients suffering from cardiac and pulmonary insufficiency without evidence-based data [38, 52,53,54,55]. In our experience, this pre-operative test will allow a surgical repair for patients with high comorbidities, without cardiac or respiratory failure [4].

  • The resultant increase in the volume of the abdominal cavity can allow the complete reduction of the herniated organs without alteration of the abdominal wall (i.e. no CST necessary).

  • The consequent pneumatic dissection of visceral adhesions facilitates the required dissection during the operation.

2.4 PPP Protocol

PPP can be either performed by repetitive percutaneous punctures with a Palmer needle under local anesthesia or with a percutaneous catheter implanted into the peritoneal cavity [4, 36, 43, 52, 56,57,58]. The use of a permanent catheter facilitates the entire process until the surgical intervention, but leads to the increased risk of infection of the catheter that may delay the operation for several months if this occurs. Repeated punctures lead to less infection rate but increase the risk of perforation of any of the contents of the abdominal cavity. Mougin published a complication rate of 20% during the PPP procedure [59]. The majority of these were minor events, without difference between the use of a catheter or repetitive puncture. More recently, catheter placement under ultrasound or CT-scan guidance has been described, which may provide better control over localization but requires good, available and motivated radiologists [60].

Each PPP procedure consists in the injection of ambient air into the peritoneal cavity through a microporous antibacterial filter after skin disinfection (Fig. 14.4a–d). A 3-way valve attached to a 60 ml syringe is a very effective and accurate method to infiltrate the air into the abdominal cavity. The procedure should be repeated every 1–3 days for 15–30 days. The volume of air injection during each procedure (500–2000 ml) and the duration of the entire procedure will depend upon the volume of the VIH [47] and patient tolerance to each instillation. This will be manifested by either scapular or abdominal pain and/or dyspnea which can limit the amount of air and/or result in the need for administration of an analgesic agent [4].

Fig. 14.4
figure 4

PPP procedure using iterative puncture with a palmer needle. (a) Skin disinfection. (b) Local anesthesia. (c) Insertion of the palmer needle. (d) Insufflations of the cavity with ambient air. (e) Plain abdominal X-Ray showing the pneumoperitoneum under the diaphragm. (f) From the first session and until the day of the operation, all patients are equipped with an abdominal belt

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After the initial procedure, a plain abdominal x-ray should be performed to check the presence of a pneumoperitoneum indicated by free air under both hemidiaphragms. (Fig. 14.4e). During the PPP and until the day of the operation, all patients should be equipped with an abdominal belt for active respiratory therapy in attempt to tolerate the progressive abdominal hypertension and to increase the respiratory capacity (Fig. 14.4f). In case of any dermatologic or septic skin condition, every attempt was made using detergent and antiseptic topical agents to eradicate and prevent further infectious complications. This can oftimes be avoided the use of skin lubricants or creams on the abdominal skin.

The protocol should include prophylactic subcutaneous anticoagulation starting at the time of the first PPP; the prophylactic dose may need to be increased in cases of obesity [4]. The administration of a broad spectrum antibiotic therapy should be evaluated on a case-by-case basis [36]. The first two or three procedures can be performed during conventional hospitalization to evaluate the initial tolerance to PPP [42, 61] but the subsequent ones can be performed in a outpatient surgery setting [4].

To the best of our knowledge, there is no consensus published regarding the quantity of air to insufflate, nor the length of time for this preparation. Some argue that the PPP should be stopped when excessive abdominal tension is observed [35, 41, 58]. Tanaka et al. insufflated the volume equivalent to the VIH calculated on pre-operative CT-scan [47] whereas Bueno-Lledo et al. insufflated three times this volume in consideration that, at least, some of the injected air is partially resorbed [36]. The preparation time varies greatly among the series published, ranging from 4 to 64 days, allowing the final insufflation total volume to range from 1400 to 38,000 cc (Table 14.1). Future studies are needed to clarify this precise aspect of the method. Regardless, once the selected time or volume has been achieved it is generally recommended that a new CT-scan is performed so that calculations of the new volumetry and hernia size after the procedure can be calculated. This should be done before surgery to verify the significant and sufficient increase of the VAC [4, 36, 41, 44, 46, 47].

Table 14.1 Series reporting the use of PPP for the repair of IHLD of hernias with loss of domain (Since 1985, including five patients or more)
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2.5 Efficacy of PPP

As noted above, the pre-operative CT-scan allows calculation of objective data regarding the efficacy of the PPP [4, 36, 44, 46]. Dumont et al. [46] have reported an increase of the length of the right and left anterolateral muscles by an average of 83 mm on each side. Most importantly, the efficacy of PPP might be assessed by the increase of the VAC, by comparing pre- and post-PPP CT-scan volumetries, which might also be predictive of the success of the hernia repair. Sabbagh et al. [44, 48] and our team [4] reported an increase of the VAC by 22% and 53% respectively. These objective data may explain that PPP can lead to the spontaneous reduction of the herniated viscera, as shown on the post-PPP CT-scan (Figs. 14.3e and 14.5). For comparative purposes, the increase of VAC has also been reported after anterior CST in two series of 19 and 10 patients: the mean increase of VAC was 6% and 10%, respectively, which appears modest compared to PPP results.

Fig. 14.5
figure 5

CT-scan before (left) and after (right) PPP showing the spontaneous reintegration of herniated organs

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Individual and pooled data of the three main studies that reported the volumetric results and efficacy of PPP in patients with giant IHLD are reported in Table 14.2 [4, 44, 47].

Table 14.2 Individual and pooled data of the 3 main studies that reported the volumetric results of PPP and the efficacy and tolerance of subsequent reintegration surgery in patients with giant IHLD
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3 Surgical Repair: Minimally Invasive

To the best of our knowledge, no recommendation can be performed to date about the surgical technique. For an incisional hernia repair, the retromuscular sublay procedure (Rives-Stoppa), has been demonstrated by several authors to have a lower recurrence rate (3–7%) and is considered by many to be the gold standard technique [68]. For this reason, we advise this technique for the repair of an IHLD whenever possible [4].

To date, large series reporting minimally invasive approach of IHLD repair has not been published yet. It has been recently shown that transabdominal preperitoneal repair (TAPP), intraperitoneal onlay mesh (IPOM) or posterior CST can be easily accomplished using robotic surgery [69]. Nevertheless, application of laparoscopic or robotic ventral hernia repair is often limited by hernia morphology [70]. We argue that a minimally invasive repair of IHLD does not allow the complete closure of the defect to be guaranteed. If this cannot be accomplished there will be a risk of the use of a bridging repair which may lead to higher post-operative complication and recurrence rate [71]. Even though minimally invasive hernia repair continues to gain in popularity rapidly, general surgeons have yet to develop the ideal, standardized method that adequately decreases common postoperative complications, such as wound failure, hernia recurrence and pain. The advent of robotics has made some complex repairs more feasible, but only time and well-designed clinical studies will tell if this will be a durable modality for ventral and incisional hernia with loss of domain repair [72].

4 Results of Surgery

Table 14.1 reports the series published about the use of PPP, on patients with IHLD and ventral hernias with loss of domain. Briefly, regarding long-term efficacy, hernia repair preceded by PPP seems to yield a low rate of hernia recurrence. Tanaka et al. reported only one recurrence (4%) after two years of follow-up [47]. Our team noticed three recurrences (8%) after a mean follow-up of only 18 months with the use of a nonabsorbable mesh [4] . The crucial point highlighted in Table 14.1 is represented by the excellent rate of surgical success, i.e. the complete closure of the defect in almost all cases after PPP. Nevertheless, recurrence, morbidity and mortality rates are still scarcely reported in the available literature concerning the treatment of IHLD, in particular after preparation with PPP.

5 Conclusion

CT scan with volumetry allows objective measurement of the exteriorized volume thereby aiding in the diminution of the risk of post-operative respiratory complications and appreciation of the efficacy of the preparation. The PPP, also called “Goni Moreno protocol”, is a useful alternative technique to CST inducing a significant extension of the anterolateral abdominal muscles and increasing the abdominal cavity volume allowing an “ideal” treatment of IHLD.

PPP is relatively well tolerated by patients treated for an IHLD, and hernia repair preceded by PPP seems to yield good outcomes with low rate of hernia recurrence and serves to minimize the risk of postoperative abdominal compartment syndrome. PPP serves in the capacity of both a therapeutic endeavor and a pre-operative test for tolerance of the surgical repair. The main advantage of PPP compared with CST is the possibility to close large defects without transection of any abdominal wall muscle. If one is surgically unable to effect a closure of the midline, CST can be always be performed in addition to the PPP. To our knowledge, no study to date has compared PPP with CST. Overall, the studies reporting separately on PPP and on CST are not directly comparable, and whether PPP should be a relevant alternative or an adjunct to component separation needs to be discussed. PPP can be performed for all IHLD whatever the abdominal location, whereas CST is primarily designed for median IHLD and can be performed in emergency. The use of PPP preoperatively for robotic assisted hernia repair needs further elucidation but with the expansion of robotic component separation, future study needs to be performed.