*6.2.1 Bleeding, suture dehiscence, and pelvic abscess: to close or not to close the defect?*

Postoperative rectal bleeding after TEM or TAMIS is the most frequently reported complication with a variable incidence ranging between 1.7% and 10.8% [56–58]. Nevertheless, in the literature the definition of rectal bleeding as a complication is heterogeneous, because the presence of a wound inside the rectum, whether completely sutured, partially sutured, or left open, causes variable blood emission after contact with the stools and with increasing internal pressure inside the rectum during defecation. This is a common occurrence, and it may be considered normal within the process. Therefore, rectal bleeding should be considered a cause of concern when the amount of blood loss produces anemia requiring blood transfusions and those requiring surgical revision, considering that more than 50% of post TEM/TAMIS bleeding

episodes are self-limited. Some authors observed that bleeding is more consistent if it is associated with suture line dehiscence in patients with defect closure, and it is more frequent in patients whose defect was left open [59, 60]. Other authors instead did not observe a correlation between defect closure and risk for postoperative bleeding [15, 44]. Postoperative bleeding seems to be significantly reduced following the use of ultrasonic dissection during local excision, as compared with diathermy (1.1% vs. 6.3%) [44, 61]. According to Lee et al., postoperative bleeding was less common in sutured defects [12]. A retrospective analysis of 220 patients with full-thickness excision and 210 patients with partial-thickness excision showed an incidence of 30-day complications analogous for open and closed defects after full-thickness (15% vs. 12%, p = 0.432) and partial-thickness excisions (7% vs. 5%, p = 0.552). Although fullthickness excision in patients with open defects had a higher rate of clinically relevant postoperative bleeding complications (9% vs. 3%, p = 0.045) [62].

Use of hemostatic agents at the end of the resection is commonly part of the clinical practice; however, no focused trials have been published reporting its effectiveness in prevention of postoperative bleeding. In patients with consistent bleeding, usually endoscopic hemostatic techniques (argon, clipping, adrenaline injection), or TEM/TAMIS revision with defect suturing (or resuturing) may be effective in managing this complication without the need for creation of a diverting stoma or resorting to an anterior resection procedure [54, 57, 59].

The suture line dehiscence rate after full-thickness TEM and TAMIS is not negligible, and in the literature, it ranges between 2% and 22.7% [16, 17, 44, 63, 64]. Its clinical presentation may range from paucisymptomatic cases to a variable symptoms' collection including rectal pain, bleeding, fever, and development of a pelvic abscess. Endoscopy is the primary investigation to assess the presence of suture line dehiscence, whereas transanal ultrasound, MRI, and CT scan should be reserved to the patients suspected for having developed a pelvic abscess. Many factors have been considered responsible for suture line dehiscence: tumor size and location [44], type of resection (full thickness), depth of excision, degree of tension on the suture line [16], type of suture (multiple interrupted sutures or single running suture) [60], previous neoadjuvant therapy [63, 64], and rectal wall ischemia [17]. Lateral or anterior location of the tumor associated with a defect size of 2 cm or more seems related to an increased risk of postoperative bleeding and pelvic collection with sepsis [56]. Bignell et al. reported that for lesions sited within 2 cm from the anal verge, an increased rate of complications occurs [44]. The risk of postoperative complications after neoadjuvant chemoradiotherapy was also reported by several authors [63, 64]. The high rate of suture line dehiscence in irradiated patients who underwent TEM/TAMIS could be a consequence of the detrimental effects of radiotherapy on the tissue, (free radical formation, DNA damage, tissue fibrosis, vascular thrombosis), with a consequently higher risk of suture line dehiscence and infection [65]. Moreover, in TEM irradiated patients, both sutured wound edges were previously irradiated, presenting all listed detrimental causes of damage, therefore the risk of wound complication is increased [63]. Some authors [16] suggested the degree of tension on the suture line and perirectal collection formation as primary causes for suture line dehiscence. This is particularly relevant in relation to extended endoluminal resection partially including perirectal fat, in which not only defect closure is mandatory to avoid pelvic contamination but the lack of tissue around the rectal wall resection becomes a "locus minoris resistentiae" where fluids collect increasing the suture line tension. With the aim of avoiding perirectal fluid collection, these authors proposed to stuff the rectal ampulla with two iodoform gauzes and to

#### *Local Excision for the Management of Early Rectal Cancer DOI: http://dx.doi.org/10.5772/intechopen.105573*

place a transanal Foley catheter with its tip well above the suture line for postoperative gas evacuation to be kept in place for 48 h. The rationale is to prevent overdistention of the rectal ampulla and at the same time obtain a moderate pressure to obliterate the remaining perirectal cavity. A wider residual cavity is subject to collection of larger amounts of fluids, which may lead to infection. This infected collection may spontaneously drain through the suture line, which in turn may lead to wound separation. The described technical details have reduced the dehiscence rate in the authors' series from 12 to 0% for wide endoluminal resection independently of tumor location and previous radiation treatment.

Pelvic abscess occurs due to intraoperative seeding of bacteria aided by dissection into the retroperitoneum and diffusion from carbon dioxide insufflation. Extension of infection from the anal region into the retroperitoneum has been reported in the literature. Bacterial seeding may cause presacral and perirectal abscess that can extend into the perineal space or to the retroperitoneum along the psoas muscle. Its clinical presentation includes pelvic and anal pain, fever, increased inflammatory markers up to sepsis. Diagnosis requires radiological confirmation by CT scan or MRI to evaluate the extension of the infectious process and the involvement of pelvic and retroperitoneal structures. The occurrence of suture line dehiscence in fullthickness excision is considered a risk factor for pelvic abscess development. Bignell et al. series of 262 patients who underwent TEM for lesions located within 2 cm from the dentate line was associated with a higher incidence of pelvic sepsis (p < 0.02). Surprisingly, no statistical correlation between defect closure and pelvic abscess was found [44]. Many patients with pelvic sepsis were managed with diverting colostomy aimed at reducing perineal contamination [44, 63, 66]. Interventional radiology (IR) development, together with the extension of indications for percutaneous drainage, has progressively replaced the need for surgical revision in a large part of retroperitoneal and pelvic collections. Generally, retroperitoneal abscess management strategies include conservative treatment with antibiotics in association with radiologically guided percutaneous drains, versus traditional surgical exploration with abscess drainage and eventually fecal diversion [44, 63, 64, 66, 67]. The need for protective stoma should be evaluated and considered particularly in relation to the abscess extension and patients' septic state. Small retroperitoneal abscesses (less than 3 cm in diameter) in a hemodynamically stable patient may be effectively treated with an extended course of antibiotics alone. However, larger abscesses or unresolving smaller abscesses must be drained either by percutaneous drain placement or by surgical exploration and drainage. Microbiological examination is required to shift from empirical antibiotic therapy to a tailored one. Surgery offers several advantages over IR drainage, including the ability to fully explore the anatomy and extent of the infection as well as the ability to remove fistulous tracts [68]. However, surgery does carry more significant risks, delays, and morbidity. Resolution and recurrence are similar between the surgical and IR approaches [68].

Concerning the issue of defect closure indications, several studies have directly compared the outcomes of leaving the defect open versus suture closure, reporting variable results. The first randomized controlled trial (RCT) on this subject, with short follow-up at 30 days [15], showed postoperative bleeding to be the only complication encountered, and both techniques were judged to be equally safe. This result was confirmed by a large multicenter comparative study in which the rectal defects were left open in 47% of patients, without increased complications [52]. However, a more recent study has postulated that open management of the rectal defect after TEM may be associated with a higher postoperative complications rate (19% vs. 8.4% p = 0.03)

but also with lower readmission rates (4.7 vs. 12.4%, p = 0.01) [60]. Brown et al. also underlined the importance of performing defect closure as a surgical training modality to achieve rectal wall suturing skills, because involuntary opening of the peritoneum during transanal excision does require such technical skills to manage this complication without conversion.

Another topic of concern has been the association of TEM defect management and increased postoperative pain. This was reported by a 2011 study, stating that postoperative pain after defect suture closure was associated with a high readmission rate and a high incidence of wound dehiscence [69]. However, a more recent multicenter RCT has refuted these results, reporting no difference in postoperative pain between sutured or open defect management [70]. In conclusion, there is no evidence that closure of the defect will prevent complications, both approaches being equally safe. Nevertheless, the decision to close or not the defect, particularly after full-thickness excision, should be evaluated according to multiple parameters, including tumor position and size, extension and depth of resection, and surgeon's technical skills.

#### *6.2.2 Rectovaginal fistula (RVF)*

Rectovaginal fistula after transanal excision is a rare iatrogenic complication, but a particularly challenging one to treat. In the literature it has been reported in a few series with an incidence rate of 0.5%–2.3% [62, 66]. It usually occurs after excision of anteriorly located lesions in women. The integrity of the rectovaginal septum should be monitored during surgery, and a vaginal examination is performed in case of doubt. Vaginal fistulas can result also from suture line dehiscence after defect closure of anterior lesion with development of a perirectal collection draining through the vaginal orifice, due to the poor vascularization and fragility of the rectovaginal septum, to the higher intraluminal rectal pressure and to the even higher pressure exerted on it during defecation. These fistulas are difficult to treat, requiring in many cases multiple reinterventions, starting with creation of a temporary stoma and subsequent repair of the fistula, which may be subject to failure. Typical clinical presentations include vaginal passage of air, stool, purulent drainage, or ill-smelling discharge, often associated with urinary infection. Diagnosis includes digital rectovaginal bimanual examination, vaginoscopy and proctoscopy, transanal blue methylene test, or transanal injection of iodine contrast agent followed by conventional X-ray or CT scan and MRI. Across the years, different techniques have been proposed for the surgical management of this complication: skin flaps, muscle flaps, musculocutaneous flaps, intestinal flaps, and the Martius flap, including subcutaneous tissue and bulbocavernosus muscle from one of the labia minora, and graciloplastica. The success rates ranged from 62–92% for patients not previously treated by radiotherapy and not affected by inflammatory bowel disease [71–77]. Among the unusual indications for TEM, there is also the possibility to close the fistula orifice after fecal diversion by a deferred transanal approach, as described by some authors in small series with good results [78–80].

#### *6.2.3 Pneumoretroperitoneum*

Under physiologic conditions, rectal intralumenal air pressure ranges between 5 and 25 cm H2O, but during transanal procedures, the intralumenal pressure increases due to gas insufflation [81]. Common to all cases of pneumo-mediastinum and pneumo-retroperitoneum, the pathophysiological mechanism begins with gas

### *Local Excision for the Management of Early Rectal Cancer DOI: http://dx.doi.org/10.5772/intechopen.105573*

migrating from the pelvis to the retroperitoneum and then to the cervical spaces, passing through the diaphragmatic hiatus, the posterior mediastinum, following the course of tracheal and esophageal walls, and then through any space delimited by skull, diaphragm, and both anterior and posterior cervical fasciae (the so-called Godinsky's space) or the retropharyngeal space [81]. Air migration might be limited in overweight and obese subjects, as fat fills in all anatomical spaces. In patients who underwent general anesthesia, it is very important to exclude other causes of extralumenal gas, such as esophageal or tracheobronchial perforations that may occur intraoperatively during nasogastric tube positioning or endotracheal intubation. In most cases, treatment may be conservative with restricted diet, intravenous antibiotics administration, and close observation [12, 82–85], although some authors prefer to treat this condition by fecal diversion [86, 87]. The presence of perirectal fluid and gas collection aerosol dissemination of bacteria and the subsequent risk of cardiac and respiratory infection or generalized sepsis must be considered in evaluating the opportunity of operative management. Frequent clinical symptoms reported in the literature are fever, pain, and subcutaneous emphysema, together with other less frequent symptoms such as dyspnea, dysphagia, or positive Kernig's sign. Fever seems to be a recurrent finding especially during the first postoperative day, without specific correlation with a septic state in patients who do not present with fluid collection or abscess [12, 82–85]. Fever could be related to transient aerosol dissemination of enteric bacteria trough the fascial spaces. Asymptomatic fever with no clinical evidence of infectious site has been described also in patients not presenting with pneumoretroperitoneum or subcutaneous emphysema, showing a self-limited trend with resolution within 2–3 days [50, 54, 66, 88].
