Modern management of acute complicated diverticulitis has evolved towards more conservative and less aggressive operative strategies, incorporating minimally invasive strategies, initially adopted only for elective surgeries. While open sigmoid colectomy with end colostomy currently remains the most commonly used procedural strategy for the treatment of perforated diverticulitis with generalised purulent/faeculent diverticular peritonitis (Hinchey III/IV) [1], two major advances have recently challenged this traditional approach. These innovations are first directed towards increasing attitude in performing primary colorectal anastomosis as an alternative to end colostomy since the role of primary anastomosis (PA) is now better understood [2], and secondly laparoscopy has become an increasingly accepted tool for urgent colectomy in emergency surgery. Even in case of a Hartmann’s procedure is decided, laparoscopy can be successfully used for both the first-stage resection and colostomy [1, 3] as well as for the subsequent elective stoma reversal [4]. Nonetheless, open surgery generally continues to be considered the only feasible and safe approach for treating patients with Hinchey IV; in fact whenever free feacal matter is found in the abdominal cavity, laparoscopy is commonly considered to be contraindicated from the beginning and conversion to open surgery is deemed necessary for technical feasibility.

Procedure

The peritoneal cavity is insufflated after a standard open Hasson technique through the infraumbilical linea alba. When feacal peritonitis (perforated diverticulitis of stage Hinchey IV) is found, provided an accurate pre-operative selection of those patients being good candidates for laparoscopy and having the necessary haemodynamic stability and absence of septic shock, laparoscopy and pneumoperitoneum can be safely continued if advanced both colorectal and laparoscopic surgical skills are available. Working ports may then be placed under direct vision, as necessary; three additional ports were used in this case. We prefer to use bladeless trocars with the aim of minimising the potential risk of iatrogenic injuries in case of gross visceral distension and adhesions secondary to peritonitis. The trocars are positioned as for a traditional laparoscopic sigmoidectomy, with possible addition of a fourth trocar in left flank. A diagnostic laparoscopy may then be performed, and the entire procedure can be eventually completed laparoscopically. Following the inspection of the peritoneal cavity, the technical challenge is how to remove quickly, effectively and moreover without contamination of the abdominal wall, the solid stools. In such patients, avoiding wasting time in removing the faecal matter and cleansing the abdominal cavity is therefore a priority. The faecal spillage is either aspirated with large bore suction devices or, in the case of solid material, we suggest, as a technical tip, using a tight sealing endobag. The endobag is useful for both the scooping of solid faeces and their subsequent rapid and protected retrieval and extraction from the peritoneal cavity. This trick can be easily repeated using consecutively multiple endobags, when the amount of faecal solid matter is large and a single endobag is not enough. Aspiration and generous lavage in all quadrants are repeatedly performed until clean. After reassessment, the laparoscopic sigmoidectomy is performed using a standard medial-to-lateral approach and clipping of the sigmoid vascular branches and section with flexible endostapler on the upper rectum, after proper dissection of the superior mesorectal space. The colonic resection should always include a full sigmoid resection, going all the way down until the upper rectum. The rectum is stapled on the passage between upper and mid-rectum, at the level of the peritoneal reflection, after careful identification and eventual ligation of superior rectal vessels, carefully preserving the middle rectal vessels.

It is our practice to avoid limited sigmoid resections, including in the emergency setting, for two main reasons: first, the diverticular disease typically affects diffusely the entire sigmoid colon, and if a full resection is undertaken, the patient will not only likely benefit from complete removal of the pathology, but also the surgeon can be sure that the anastomosis will not fall on a diseased colonic wall, which is easily inflamed and possibly affected by residual diverticula. Second, after division of the inferior mesenteric sigmoid branches (Fig. 1, blue lines), the remaining proximal and distal sigmoid stumps (if a limited sigmoid resection is undertaken, Fig. 1, red lines) are often not well perfused due to the colonic vascular anatomy, and therefore, the risk of anastomotic leak can be increased because the remaining colonic and rectal vascularity is altered (see Fig. 1). The anatomy of colonic and rectal vascularity advocates for a complete sigmoid resection, with the anastomosis better being performed between the distal descending colon and the rectum (Fig. 1, green lines); this represents our standard practice in all cases of diverticular sigmoid resection.

Fig. 1
figure 1

Green lines (Fig. 1a) suggest the best level of a full sigmoid resection, falling on well perfused colonic segment, which should be less inflamed and free of diverticula; red lines are showing the level of a limited resection which should be avoided, because it is leaving residual proximal and distal sigmoid colonic edges being poorly vascularised, often inflamed and with residual diverticula; blue lines indicate the usual level of the vascular ligatures of the sigmoid branches, which must be taken into consideration for the subsequent vascularization of the residual colon to be anastomosed; the outlined triangles (Fig. 1b) are showing the areas of sigmoid where an anastomosis is at risk and should be avoided and that should be instead included within the colonic resection specimen (Color figure online)

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The sigmoid should be always fully mobilised from the retroperitoneum, carrying out the dissection on the avascular plane between the origin of the mesocolon and the retroperitoneum; this plane is relatively easy to identify and safe to follow, especially in the presence of peritonitis and severe inflammation with oedematous and thickened mesenteric tissues.

Once the colon and upper rectum have been fully mobilised, surgical attention turns to the vascular pedicle. The mesocolon is divided upwards until reaching the origin of the left colic vessels, which must be identified and we usually carefully preserve for the maintenance of maximal vascularisation of the proximal colonic stump. Ligation of these vessels is not necessary in a sigmoid resection for benign disease. The vascular pedicle is clipped and/or stapled depending on the quality, in particular the oedema, of the tissue; with extreme mesenteric inflammation, the thickened and oedematous tissue may preclude ready identification of the vessels for safe clipping, and using an endostapler with vascular load may be preferable (Fig. 2). This is often encountered in Hinchey stage II and stage III disease; while the colonic perforation may be limited and/or covered, the surrounding inflammation may have been present and active from long time (days) and therefore be intense because it was long-lasting.

Fig.2 
figure 2

The vascular pedicle is clipped and/or stapled depending on the quality, in particular the oedema, of the tissue; with extreme mesenteric inflammation, the thickened and oedematous tissue may preclude ready identification of the vessels for safe clipping, and using an endostapler with vascular load may be preferable, allowing a quick mesentery stapling with reliable vascular control. This is often encountered in Hinchey stage II and stage III disease or whenever a pericolic/mesenteric abscess is present; while the colonic perforation can be limited and/or covered, the surrounding inflammation may have been present from long time (several days) and therefore be intense because it was long-lasting. (intraoperative pictures provided from Dr. S. Di Saverio MD FACS FRCS surgical procedures)

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It is our standard practice to also fully mobilise the splenic flexure in order to allow a floppy and un-tethered descending colon, removing any possible tension proximally.

The proctosigmoid specimen, still attached proximally, is extracted through a mini-Pfannenstiel incision with muscle splitting technique and assistance of a self-retaining wound protector. Muscle splitting is able to minimise post-operative pain, decreases the risk of developing a local haematoma and reduces SSIs. The full and generous mobilisation of the sigmoid colon before its extraction ensures that the bowel is floppy and may be easily delivered and extracted through a very small (usually 4–5 cm) mini-Pfannenstiel incision (Fig. 3). Care should be taken to confirm that the site of the perforation and the hole is included within the resected specimen. This obvious issue may be overlooked in cases of small or microscopic perforations; the defect may be hardly visible within a thickened inflamed colonic wall. To ensure the avoidance of this error, and with the benefit of the magnified laparoscopic view identifying the perforation, an intracorporeal stitch may be placed proximal to the perforation site, in order to mark the minimum proximal margin to be achieved during resection. However, irrespective of the site of perforation, we recommend a complete sigmoid resection, ensuring that all the diseased and inflamed sigmoid colon is resected. Furthermore, this complete resection, and subsequent anastomosis between the descending colon and the upper rectum, will most probably fall on an area free of diverticula, with tissues less inflamed and less oedematous, and well vascularised from the left colonic vessels and the middle rectal vessels.

Fig.3
figure 3

The proctosigmoid specimen is extracted through a mini-Pfannenstiel incision with muscle splitting technique and assistance of a self-retaining wound protector. Muscle splitting is able to minimise postoperative pain, decreases the risk of developing a local hematoma haematoma and reduces SSIs. The full and generous mobilisation of the sigmoid colon before its extraction ensures that the bowel is floppy and may be easily delivered and extracted through a very small (usually 4–5 cm) mini-Pfannenstiel incision. Care should be taken to confirm that the site of the perforation and the hole is included within the resected specimen. It is also a good advise to feel the presence of a good arterial pulse in the mesentery of the proximal colon before deciding the optimal level for transection. Finally is shown the extracorporeal division on the passage between sigmoid and descending colon before the anvil placement within the proximal stump. Last panel is showing the portoperative cosmetic and functional outcomes of a muscle-splitting mini-Pfannenstiel incision. (intraoperative pictures provided from Dr. S. Di Saverio MD FACS FRCS surgical procedures)

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The bowel is transected proximally at the level of descending colon where a well-vascularised wall has been demonstrated and confirmed (surgeons must check the presence of good blood supply and microvascularisation at the time of section of the colon with cold blade). Colonic transection at the level of the pubis ensures that the length of the proximal colon is enough to allow performing a tension-free anastomosis. The stapler anvil is inserted and secured with the aid of a purse string. The proximal bowel, with anvil attached, is then returned into the peritoneal cavity. The mini-Pfannenstiel incision is closed and the pneumoperitoneum re-established. Finally, a transanal intracorporeal colorectal Knight–Griffen anastomosis is formed. We routinely conduct an air-leak test, and finally, drains are inserted and placed where appropriate. Depending on the clinical situation and upon the operating surgeon’s preference, a diverting loop ileostomy may be fashioned. However, when deciding for an ileostomy, it must be kept into consideration that in such conditions the whole colon between the ileostomy and the anastomosis is unprepared. Furthermore, these patients did not receive preoperative radiation or chemotherapy, the anastomosis is not particularly low, but usually above or at the level of peritoneal reflection, and the most important factors influencing a leak are probably the good vascularisation and blood supply of the anastomotic colonic edges.

Occasionally, for either anatomic or perhaps deteriorating physiological reasons, it may not be possible to perform the primary, colorectal anastomosis, as described above. In this situation, the procedure can be abbreviated to a Hartmann’s procedure, with the formation of an end colostomy. The surgical procedure is analogous to the point of specimen extraction. In the laparoscopic Hartmann’s, instead of the mini-Pfannenstiel incision, a small incision at the future stoma site is made in the left iliac fossa and used for specimen extraction.

The sigmoid is completely resected at its distal end with flexible endostapler and is fully mobilised by clipping or stapling of the mesentery. The division of the mesentery is completed, and the colon is extracted through the wall incision starting from the distal stapled end. After the entire proctosigmoid is delivered, including the perforation site and the entire diseased colonic segment, the proximal resection is performed with cautery on the well-vascularised descending colon. The serosa of the colostomy loop is stitched to the fascia, and finally, the stoma is everted. The cut edges are then sutured down to the skin as the end colostomy (the whole procedure is shown in Fig. 4). The pneumoperitoneum is then re-established, and the untwisted, correct orientation of the stoma bowel loop and colonic mesentery confirmed. A final aspiration and lavage, as well as placement of appropriate drains, completes the procedure.

Fig. 4
figure 4

Operative steps of a Laparoscopic Hartmann: Upper right and left panels show the extraction of the sigmoid specimen through the wall incision made on the left flank at the site chosen for stoma creation, starting from the distal stapled end. Lower right panel is showing how, ffter the entire proctosigmoid is delivered, including the perforation site and the entire diseased colonic segment, the proximal resection is performed with cautery on well-vascularised segment of descending colon. Then the colostomy is secured to the fascia and skin. Finally in the lower left panel is the postoperative appearance of the end-colostomy fashioned after a minimally invasive Hartmann's procedure. The entire procedure has been carried out laparoscopically and the stoma site has been used for extraction of the specimen without need of further incisions or neither of a mini-Pfannestiel (intraoperative pictures provided from Dr. S. Di Saverio MD FACS FRCS surgical procedures)

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Clinical case video

The video shows the operative technique of one-stage laparoscopic sigmoid colectomy with primary colorectal anastomosis in a 35-year-old man with severe and diffuse free faeculent diverticular peritonitis (Hinchey IV). The patient had presented to Emergency Department complaining of sharp sudden abdominal pain, with onset <12 h earlier. Urgent CT scan showed extraluminal air bubbles and free fluid between the bowel loops. The patient remained haemodynamically stable during either the preoperative period and under anaesthesia. The patient, accurately informed, was enrolled within the LADIES trial [5]. Laparoscopic exploration revealed the presence of free feacal matter and solid stools in the abdominal cavity, leaking from a large perforation of the diseased sigmoid colon. Intra-operative randomisation resulted in sigmoid resection and primary anastomosis. The Peritonitis Severity Score [6] was low (7 points), Mannheim Peritonitis Index (MPI) [7, 8] was 18, and the estimated preoperative duration of peritonitis was <24 h. A minimally invasive sigmoid colectomy with immediate restorative procedure (primary colo-rectal anastomosis) was performed. Key operative steps included: (1) rapid and complete removal of the solid stools with multiple endobags device followed by copious lavage of all quadrants, (2) a medial-to-lateral mesenteric division with mobilisation of the sigmoid and descending colon followed by takedown of the splenic flexure, (3) superior rectal vessels ligation and division, (4) dissection of the upper third of the rectum and stapled transection just below the sacral promontory, (5) completion of colonic mobilisation from the retroperitoneum until left colic vessels identification (must be preserved), (6) exteriorisation of the specimen through a 4-cm mini-Pfannenstiel muscle splitting incision, (7) extracorporeal division on the passage between sigmoid and descending colon and the anvil placement within the proximal stump and (8) re-establishment of pneumoperitoneum and fashioning transanal circular stapled anastomosis under direct vision. The total operative time was 210 min. The patient was managed post-operatively according to ERAS guidelines, with early mobilisation and early oral soft diet. After uneventful post-operative course, the patient was discharged home on the ninth post-operative day.

Discussion

Emergency laparoscopy and minimally invasive emergency surgery (MIES) are able to achieve and to demonstrate the most significant advantages over open surgery [9], particularly in cases of severely septic patients that, such as those with Hinchey IV and faeculent peritonitis, provided the patients are haemodynamically stable and not in shock, therefore able to tolerate the pneumoperitoneum. The surgical stress response and post-operative immune function are in fact more favourable following laparoscopy and minimally invasive surgery, compared with the traditional, open approaches. The decreased release of pro-inflammatory elements from the mitochondria minimises both local and systemic effects that are causing or worsening widespread inflammation and precipitate secondary organ injury (particularly to lung and kidneys), typically experienced in such patients [10]. Therefore, we hypothesise that the immune response correlates with inflammatory markers associated with injury severity and, as a consequence, the magnitude of surgical interventions may influence the clinical outcomes through production of molecular factors, ultimately inducing systemic inflammatory response. Increasing evidence supports the thought that, by inflicting less trauma with a more liberal use of laparoscopy, the healing response is more efficient, especially in septic patients [11], yielding improved clinical outcomes, as observed in our case.

In conclusion, this case illustrates the technical feasibility of a minimally invasive single-stage surgical procedure for the management of severe acute perforated diverticulitis, even in cases of Hinchey IV with diffuse faeculent peritonitis. Laparoscopy and primary intracorporeal anastomosis, when advanced laparoscopic [12] and colorectal surgical skills are available [13] and can be deployed in the emergency setting, may offer clear advantages and excellent results even when performing emergency colorectal surgery and for patients with Hinchey IV perforated diverticulitis, likely from the known benefits associated with MIS. In spite of the severe and diffuse acute peritonitis, the faecal contamination is quickly and effectively dealt with and the free solid matter can be completely removed laparoscopically, using a combination of large calibre suction devices and a novel application of endobag devices, appropriately closed for aiding the protected retrieval. Thereafter, the diseased sigmoid colon  is dealt with according to the standard laparoscopic fashion, the resection can be safely and entirely performed laparoscopically, and the specimen extracted either from the left flank through the same site where end colostomy can be fashioned (in case of laparoscopic Hartmann resection) or via a mini-Pfannenstiel incision of 4–5 cm and a laparoscopic primary transanal circular anastomosis can be performed, in case of primary anastomosis id decided (as it has been in the present case). Our operative algorithm for patients with Hinchey IV perforated diverticulitis is primarily dependent on haemodynamic stability (essential prerequisite for pneumoperitoneum) as well as on severity and duration of peritonitis (Fig. 5), with a careful selection for minimally invasive surgery (laparoscopic sigmoidectomy and eventual primary anastomosis) or an open damage control surgery (with colostomy and eventual open abdomen) in the compromised patient. Last but not least, laparoscopic approach should be attempted only in the presence of advanced minimally invasive surgical skills. We do not recommend use of laparoscopic lavage at all in case of intraoperative findings consistent with Hinchey IV (associated by definition with a free colonic perforation), whereas patients with “Severe sepsis and septic shock” (where severe sepsis is defined as sepsis-induced tissue hypoperfusion or organ dysfunction and septic shock is defined as severe sepsis associated with persistent hypotension and BP < 90/60 mmHg despite adequate fluid resuscitation) should never be approached laparoscopically but with open surgery. Also in such patients, the duration and severity of peritonitis should advice on the opportunity of performing a colostomy and eventually open abdomen if gross visceral oedema [14]. Appropriate patients selection is critical to the success of any surgery, and of particular relevance in the setting of tailored surgical therapies, such as discussed here. A laparoscopic approach will likely be of a longer duration, and expose the patient to greater physiological stress, compared with an open, rapid, potentially abbreviated, laparotomy, such as performed in a damage control strategy for severe intra-abdominal sepsis in association with physiological extremis [15]. To tolerate the laparoscopy, the patient must be haemodynamically near-normal, receive a good resuscitation and be in a surgical environment where both the facilities and surgical skills for such an intervention are immediately available. As a result, the appropriateness of such an advanced, tailored surgical therapy, and its feasibility, must be under continued surveillance intra-operatively. Patient selection is key for a successful clinical outcome in the minimally invasive emergency surgical intervention, as documented in this experience.

Fig. 5
figure 5

Proposal of an operative algorithm for surgical decision-making in the management of patients with Hinchey IV perforated diverticulitis. The decision-making is primarily dependent on haemodynamic stability (essential prerequisite for tolerating the pneumoperitoneum) as well as on severity and duration of peritonitis, with a careful selection process between patients candidates for minimally invasive surgery (laparoscopic sigmoidectomy and eventual primary anastomosis) if hemodynamically stable or open damage control surgery (with end-colostomy and eventual open abdomen) in the compromised patients with septic shock and unstable hemodynamics (Algorithm developed by Dr. S. Di Saverio MD FACS FRCS)

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