Mikelangelo: переводы

→Transanal hemorrhoidal dearterialization with mucopexy provides plication of the rectal submucosa affected by the loss of elasticity. It is reduced stably into the rectal ampulla, recovering its anatomical position. Furthermore, the scarring process induced by the mucopexy attaches the plicated mucosa and submucosa to the underlying rectal muscle.

→Normally, the hemorrhoidal cushions are loosely attached to the circular muscle through the elastic rectal submucosa, which keeps the piles in the anal canal at rest. During defecation, rolling of the hemorrhoids inside the lumen occurs, favored by the internal anal sphincter relaxation. The fecal bolus has a shearing effect on the cushions and facilitates their prolapse [14–16]. On the other hand, the elasticity of the rectal submucosa keeps the piles inside the rectum. In patients with hemorrhoidal disease, due to altered defecation and other predisposing factors [17], the rectal submucosa progressively loses its elasticity, determining hemorrhoidal prolapse [15, 16, 18]. The progressive disruption of both the connective tissue stroma (Park’s ligaments) and anchoring system (Treitz’s muscle) plays a major role. Severity of prolapse is related to persistence of pathogenic factors, engorgement of piles, and progressive loss of the elasticity of the rectal submucosa.

→Pathological anatomy of hemorrhoidal prolapse

→Mucopexy (MP)

→Following gel lubrication, the proctoscope is inserted through the anal canal reaching the low rectum, about 6–7 cm from the anal verge. The surgeon can decide to start the operation at any point of the rectal circumference and proceed in a clockwise or anticlockwise direction. The Doppler system is then turned on. The Doppler signal corresponding to all 6 main trunks of the hemorrhoidal arteries, which are usually located at 1, 3, 5, 7, 9, and 11 o’clock of the low rectal circumference, is sought by slowly rotating and/or tilting the proctoscope. However, searching with the Doppler probe makes possible correct identification of those arteries not located at the usual odd hours positions. The proctoscope is pulled slowly back to follow the artery distally up to hemorrhoidal apex, and the best Doppler signal is searched for. According to the above-mentioned features from our previous study [12], the Doppler signal is quite clear at the proximal site (corresponding to the proximal part of the lower rectum, where, however, arteries could lie in the perirectal fat), attenuated or absent at the intermediate site (where the artery is perforating the rectal muscle), and again clear at the distal site (within the most distal 2 cm of lower rectum, where the artery lies in the rectal submucosa, just above the internal hemorrhoidal piles, Fig. 3). As a consequence of anatomical and acoustic findings, the best place to find the hemorrhoidal arteries should be the most distal part of the rectum: This is the fundamental principle of distal Doppler-guided dearterialization (DDD) [13]. After identification of the best place for artery ligation, the Doppler system is turned off.
If the patient is a candidate for dearterialization alone (i.e., the patient only has bleeding without prolapse), the artery, once identified, can be directly ligated with a “Z-stitch” at the site of the best Doppler signal (Fig. 4). When the patient needs to undergo dearterialization and mucopexy (due to hemorrhoidal or muco-hemorrhoidal prolapse), the rectal mucosa can be marked with electro-cautery (“marker point”) at the site of the best Doppler signal (Figs. 5, 6) to indicate where the artery will be ligated. Then, a mucopexy follows (see below).

→In our recent study [12], the majority of arteries in the upper part of the lower third of the rectum (4–6 cm from the anorectal junction) were located outside the rectal wall. In contrast, within 2 cm from the anorectal junction, hemorrhoidal arteries were detected in the submucosa in 98 % of the 6 sectors of the rectal circumference (96.6 and 100 % of sectors at 2 and 1 cm above the anorectal junction, respectively). Therefore, in their course through the lower third of the rectum, the hemorrhoidal arteries traverse the muscularis propria of the rectum and become more superficial. These features can be easily confirmed during Doppler-guided surgical procedures. The different Doppler signals are dependent on the position of the artery (perirectal, perforating the rectal muscle, or submucosal), the distance from the Doppler probe, and the direction of blood flow in relation to the ultrasound waves emitted by the probe. In fact, the intensity of the Doppler signal is the inverse of the cosine of the angle between the ultrasound waves and blood flow. As a consequence, the more perpendicular the blood flow to the ultrasound waves (i.e., artery into the perirectal tissue or submucosa) the higher the Doppler signal. On the other hand, the more parallel the flow (i.e., artery traversing the rectal muscle) the lower the signal (Fig. 2). The proximity of the artery to the probe when the artery is submucosal makes the Doppler signal higher than that perceived at the proximal sites.

→Aim of hemorrhoidal dearterialization is to significantly reduce the arterial overflow in the hemorrhoidal tissue, characteristic of patients with hemorrhoidal disease. The anatomical and physiological characteristics of hemorrhoids have not been fully elucidated. Microscopically, hemorrhoidal tissue is composed of sinusoids, i.e., vascular structures without a muscular wall [8]. Direct arteriovenous communications have been demonstrated histologically and radiologically, and some authors have noted a resemblance to erectile tissue [9]. Traditionally, with the patient in the lithotomy position, hemorrhoids frequently appear to be localized to the left lateral, right posterolateral, and right anterolateral areas of the anal canal. However, this configuration is demonstrated in less than 20 % of patients [10]. In reality, a wider network of arterial and venous vessels has been described [11]. Schuurman et al. [1] studied 10 non-fixed human cadavers in order to assess the arterial vasculature of the rectum and arterial supply to the hemorrhoids. Selective injections of different colors were used. The authors found that, about 2–3 cm above the dentate line, thin tortuous arteries (a mean number of 8, all branches of the superior hemorrhoidal artery) were seen lying in the submucosa, reaching into the hemorrhoidal tissue. Smaller branches from these arteries formed a plexus in the corpus cavernosum recti area.

→Technique

→Surgical anatomy of the hemorrhoidal arteries

→Distal Doppler-guided dearterialization (DDD)

→Transanal hemorrhoidal dearterialization is performed using a specific device produced by THD S.p.A., Correggio, Italy. It consists of a proctoscope equipped with a Doppler probe and a light source (Fig. 1). The Doppler probe utilizes a double crystal, which allows a more precise focusing of the ultrasound waves and capturing of large-diameter arteries located in the superficial layers of the rectal wall. Sufficient space is provided around two crystals for their adequate vibration. The Doppler probe is mounted on an oblique support, oriented toward the operative window, so that the artery identified by the Doppler signal lies within the operative window and can be selectively ligated.

The latest proctoscope model (THD Slide®, THD S.p.A., Correggio, Italy) has a sliding part comprising the operating window and the Doppler probe, so that the operator can move them proximally and distally without repositioning the proctoscope. The section of the proctoscope is elliptical, with an external maximum diameter of 32–34 mm and an internal diameter of 20–34 mm.

The recommended suture is 2–0 absorbable polyglycolic acid with a 5/8-in. needle. This is mounted on a specially designed needle holder, providing a mark on the tip where the needle should be held. With this configuration, the needle holder tip can be inserted into the pivot, and the needle rotates to transfix the rectal mucosa in a standard fashion. The depth of the transfixed stitches can be easily and safely calibrated up to a maximum depth of 6.5 mm, which includes only mucosa and submucosa avoiding penetration through the full thickness of the rectal wall and therefore lowering the risk of perirectal fistula and abscess. A knot-pusher is also provided in case is needed.

→Equipment

→The patient can be placed in either the lithotomy or the prone position, based on the surgeon’s preference. However, it should be taken into consideration that the lithotomy position allows a more realistic position of the prolapsing hemorrhoids and rectal mucosa. An accurate intraoperative monitoring of blood pressure could be helpful. In particular, systolic pressure higher than 100–110 mmHg allows auscultation of a Doppler signal necessary for the identification of the hemorrhoidal arteries.

→Transanal hemorrhoidal dearterialization can be performed under both general and locoregional anesthesia. Propofol-remifentanil anesthesia, with the placement of a laryngeal mask, combines general anesthesia, complete control of vital parameters, and quick reversion and discharge from the hospital. Spinal anesthesia may be limited to the most caudal metameric nerve roots avoiding any prolonged stay in bed. Unfortunately, spinal anesthesia is usually associated with a higher risk of urinary retention, especially following hemorrhoid surgery. More limited locoregional anesthesia (i.e., posterior perianal block) does not ensure a complete intraoperative analgesia due to the visceral pain elicited by surgical ligation, suturing for plication, and tying knots on the rectal mucosa.

→This is a matter of the surgeon’s preference as there are no absolute guidelines in hemorrhoidal surgery. The same is true also for the THD procedure. Because it is performed within the lower rectum, one or two enema(s) should be prescribed. The Author does not consider antibiotic prophylaxis as mandatory as in his experience no infections have been observed following this operation.

→Intraoperative management

→Anesthesia

→Preparation for surgery

→Patients with hemorrhoids who suffer from inflammatory bowel disease deserve a special mention. There is a lack of studies specifically addressing patients with Crohn’s disease or ulcerative colitis operated on with THD. However, providing that no severely active inflammation is demonstrated on the rectal mucosa, this method may be suitable in patients with hemorrhoids resistant to conservative treatments. The same concept applies to hemorrhoidal disease in patients with chronic radiation proctitis.

→Patients with skin tags should be advised that these are not real hemorrhoids, but the consequence of previous engorgement and dislodgement of hemorrhoidal cushions toward the perianal skin. Since THD does not provide any specific treatment for skin tags, only surgical excision can be a reliable treatment when indicated or desired.