4.1 Introduction
Laparoscopic surgery for colorectal disease demands advanced laparoscopic skills and has the potential for serious complications both intraoperatively and in the postoperative phase. Some are specific to the laparoscopic approach; others are equally common with both laparoscopic and open approaches, but methods to deal with these complications in the laparoscopic environment are often more challenging and require knowledge of specific techniques in order to avoid conversion to open surgery.
4.2 Intraoperative Complications
4.2.1 Haemorrhage
Intraoperative haemorrhage can occur in a number of different scenarios, and specific problems related to colorectal surgery are discussed. Port-site haemorrhage, for example, will not be dealt with here.
Arterial haemorrhage from a major colorectal artery is immediately evident and occurs as a result of inadvertent division (partial or complete) during the
dissection of a vascular pedicle. Inappropriate or improper use of an energy device can also lead to poor sealing of major vessels which might result in either immediate or delayed haemorrhage. Vessels may also be avulsed due to inappropriate traction although this more commonly leads to venous haemorrhage. Blood loss from this kind or injury can be rapid and requires prompt action to firstly control the blood loss and secondly to secure the vessel.
Control of haemorrhage can often be achieved with the application of an appropriate grasper to the vessel if it is visible and if there is sufficient length of vessel for a grasper to be applied. Circumstances in which there is no cuff of vessel—for example, where the inferior mesenteric artery (IMA) has been divided flush with the aorta—are more difficult. Where a grasping instrument or the energy device cannot be judiciously applied, then immediate application of pressure with a small swab accurately over the source will usually control the bleeding. Once the active blood loss is controlled, there is time to contemplate how best to proceed. Appropriate instrumentation can be made available such as a clip applicator, suction irrigation and sutures and importantly extra ports deployed in order to utilise assistance for application of pressure or suction irrigation. In any circumstance where blood loss is not rapidly controlled, then immediate conversion to open access is indicated.
When there is a cuff of a divided vessel visible, then application of a suitable sized clip is often the best method of control. There is however no place for blind clip application, and this needs to be done in a controlled fashion. If the energy source can be safely applied to a vessel of appropriate size for the device, then this is also acceptable method of control. The device should completely control the haemorrhage when applied before activation of the energy source.
Avulsion injuries are the result of poor surgical technique and can be difficult to control as the proximal end of the vessel may not be visible. It may be possible to control the bleeding with pressure before proceeding as above; but if the bleeding source cannot be found, conversion to open surgery is recommended for uncontrolled haemorrhage. More minor bleeding that is controlled with pressure may be manageable by prolonging the application of pressure and incorporating haemostatic materials.
Energy devices need to be used as per the manufacturer’s recommendations. If used incorrectly or on inappropriately sized vessels, the haemorrhage can result either immediately or in a delayed fashion. Ultrasonic devices (e.g. Harmonic ACE™ (Ethicon Endosurgery)), intelligent bipolar vessel-sealing device (e.g. LigaSure™, Covidien) and hybrid energy sources (e.g. ThunderbeatTM, Olympus), are the most widely used devices. The standard Harmonic ACE is licensed to divide and seal vessels not more than 5 mm and the newer Harmonic ACE 7 up to 7 mm. LigaSure and Thunderbeat also seal vessels up to 7 mm. Division of larger vessels with these devices alone is not recommended, and in all cases, consideration needs to be given to vessel characteristics (e.g. calcification) and to using the correct technique and power settings. In all cases, vascular pedicles should not be divided flush with the major proximal blood vessel (i.e. the aorta when dividing the IMA). Haemorrhage is both more likely and much more difficult to control. A pedicle of at least 1 cm is advisable. Vessels should be dissected and clearly identified prior to division as this allows the visualisation of the true vessel diameter and permits separate division of artery and vein. If this proves difficult, then a vascular stapling device is a good alternative (use of the correct white stapling cartridge for vascular division is necessary). For bipolar sealing devices, it is imperative that the vessel should only be divided once the instrument has indicated that the seal is complete. This is automatically detected by simultaneous measurement of the impedance of the tissue as it desiccates and seals. Ultrasonic technology is different in that the device cuts and seals simultaneously. For the seal on a major vessel to be effective, tension on the pedicle must be diminished and the “minimum” indicator set to the lowest possible (Setting one on the Harmonic ACE) to maximise coagulation and seal. Activation should be with the instrument fully closed and with no pressure on the active blade. Diseased vessels, especially those that are heavily calcified, may not seal well and clips should be applied.
Haemorrhage from a staple line is not uncommon even where the correct vascular (white) cartridge has been used. It is usually minor and stops spontaneously. If arterial and spurting, then judicious application of a clip is effective. If just oozing, then this can be effectively controlled with a swab and the bleeding will stop spontaneously.
Anatomical variation of vasculature is important principally for the understanding of the development of ischaemia and where appropriate colonic division should take place. The ileocolic artery has the most constant position originating independently from the right side of the superior mesenteric artery (SMA) in 63 % of individuals. In the remainder, it forms a common trunk with the right colic artery. The right colic and middle colic arteries can be absent, and knowledge of this is crucial when deciding upon the amount of right colon to transect. The right colic artery has the greatest variation amongst individuals. In 40 % it originates as a separate branch from the SMA and in 30 % from the middle colic artery and in 20 % is absent. In such a situation, the right colon will receive its vascular supply from the ascending and descending branches of the ileocolic and right branch of the middle colic arteries (Fig. 4.1). With this scenario, a mid ascending colon neoplasm would require division of the ileocolic and right branch of middle colic vessels. Likewise, for a caecal or proximal ascending colon neoplasm, dividing the ileocolic vessels at their origin may result in excision of a greater length of colon as the right colic vessels may be part of the common trunk. If possible, the courses of these vessels should be noted prior to division.
Fig. 4.1 Division of relevant pedicles in relation to tumour location in the right colon. (a) Right colic artery arising from the superior mesenteric artery. (b) Right colic artery arising from the ileocolic trunk. (c) Right colic artery arising from the middle colic artery. (d) Right colic artery absent. SMA superior mesenteric artery, RCA right colic artery, MCA middle colic artery, RMCA right branch of middle colic artery, LMCA left branch of middle colic artery
Alternatively, as division of the appropriate vessel is crucial, extracorporeal division may be preferable once the colon has been mobilised, if the anatomy is uncertain.
The middle colic artery usually originates from the SMA at the inferior border of the uncinate process of the pancreas. In 25 % it can be absent and in 10 % there may be an accessory or double vessel. The right and left branches of this artery arise at the middle of the transverse colon. If intracorporeal division of the right branch is contemplated, then search for it should begin from the middle of the transverse colon.
The inferior mesenteric artery (IMA) provides the blood supply to the descending and sigmoid colons and upper rectum. It originates from the anterior surface of the abdominal aorta although its position is not constant, lying anywhere along a line from the origin of the SMA to the aortic bifurcation. In most cases, the origin is just below or under the third part of the duodenum. From here the artery runs obliquely and crosses the pelvic brim at the aortic bifurcation. To prevent early injury, the first incision used to commence medial to lateral dissection should be made at the root of the sigmoid mesentery anterior to the right common iliac artery, rather than over the sacral promontory. The left ureter and gonadal vessels pass close to the IMA origin. They must be recognised and dissected clear (if necessary) before the IMA is divided. The diameter of the IMA is 50 % that of the SMA. The principles that apply to division of arterial vessels with modern energy sources and stapling devices are equally relevant to this vessel. Rarely does the IMA have to be divided at its origin. The left colic artery provides a significant blood supply to the splenic flexure. It is important to know the anatomical variations of the LCA as if this is inadvertently divided; there is a risk that this section of the colon will become ischaemic necessitating splenic flexure mobilisation and more proximal division of colon. In over 50 % of individuals, the LCA arises as a separate branch of the IMA, and in the remainder it forms a common trunk with the first sigmoidal artery (Fig. 4.2). A useful tip in identifying the LCA is to locate the IMV as the former usually travels adjacent to the latter.
Fig. 4.2 Anatomical variation of left colic artery. IMA inferior mesenteric artery, LCA left colic artery, SA sigmoidal artery, CT common trunk
4.2.1.1 Other Vascular Injuries
Injury to the common iliac arteries and external and internal iliac veins is possible, either as a trocar injury or during medial to lateral mobilisation of the left colon and total mesorectal excision of the rectum (TME). Blood loss can be
significant and this can have an impact on anastomotic integrity (see below). Repair can be achieved laparoscopically, but conversion to an open procedure and specialist vascular intervention is desirable for patient safety.
4.2.2 Ischaemia
Ischaemia of either the proximal or distal parts of an anastomosis will usually result in anastomotic dehiscence. Ischaemia insufficient to cause necrosis may later present with stricture but this is unusual. With a standardised approach to segmental colorectal resection, ischaemia is unusual but may result when there is anatomical variation of the colonic vasculature as previously discussed or probably most commonly during left-sided resection when insufficient mobilisation of the splenic flexure causes the surgeon to divide the left colon too distally in an ischaemic segment. This is most likely in cases with poor marginal artery perfusion. Mostly ischaemia of the proximal conduit can be avoided by fully mobilising the splenic flexure when necessary so that a tension-free anastomosis can be constructed using a well-vascularised bowel. Mostly ischaemia is evident from the colour of the bowel when exteriorised. There may even be a clear demarcation. A tip to ensure that the bowel is well vascularised is to always divide the marginal vessel extracorporeally. Once the level of planned division is identified, the marginal artery is divided between clips. The distal end is tied and the proximal end then gently released to observe arterial blood flow. If there is no active bleeding, then a more proximal site should be chosen. When the bowel itself is divided, there should be bright red mucosal bleeding. There may be a role for the use of Indocyanine Green (ICG) fluorescence to assess perfusion if the technology is available.
Increased blood flow to the colorectal or colo-anal anastomosis may be achieved in the following ways.
1. A more proximal division of the left colon following full mobilisation of the splenic flexure.
2. Preserve the ascending left colic artery where possible.
3. Create a side to end anastomosis.
When balancing the requirement to mobilise the splenic flexure to obtain length with preserving the ascending left colic artery, it is often feasible to divide the inferior mesenteric vein high at the lower border of the pancreas but leave the ascending colic artery intact.
4.2.3 Organ Injury
This section discusses the organs and structures most likely to be injured during a laparoscopic colorectal resection. It includes a discussion on splenic, pancreatic and gastric injury during splenic flexure mobilisation, ureteric injury during left-sided resections and total mesorectal excision and bladder trauma.
4.2.3.1 Spleen, Pancreas and Stomach
Splenic flexure mobilisation is often necessary for anterior resection of the rectum or even for more proximal segmental resection. The aim being to achieve a tension-free and well-vascularised anastomosis of healthy bowel. To assess adequate length, the planned point of colonic division can be brought down to the transected rectum intracorporeally prior to exteriorisation. Extracorporeally the end of the colonic conduit should reach well past the symphysis pubis following resection of the pathological segment in order to reach the pelvic floor comfortably when replaced intracorporeally for anastomosis.
Splenic injury seems to be much less common during laparoscopic surgery than in open surgery. This is because most splenic injuries are a result of traction of the colon, which avulses splenic capsule tissue at the site of congenital adhesion. At open surgery, too much traction can be created and the sites of adhesion are not well seen. Nevertheless, the same problem can occur at laparoscopic surgery, or direct trauma can occur in inexperienced surgeons especially in fat patients with fatty omentum obscuring the natural planes between spleen, omentum and transverse colon. The operator should be aware of potential injury to the spleen, short gastric vessels and pancreas. Excessive colonic retraction can cause bleeding from a tear in the splenic capsule. It can go unrecognised and so should be investigated when blood is noticed pooling in the left upper quadrant. The most likely site for a tear is at the inferior border or hilum. Primary suture repair and/or application of modern haemostatic agents such as fibrin glue or cellular polymer and radiofrequency ablation with pressure should be considered before contemplating a splenectomy [1]. Very effective haemostatic materials are available which are effective even in significant splenic injury, and all abdominal surgeons should be trained in the correct use of these materials. Inappropriate traction on the stomach may result in trauma to the short gastric vessels. During splenic flexure mobilisation, the stomach does not need to be retracted and so should be avoided. There may be times when the lesser sac needs to be entered between the transverse mesocolon and body of pancreas. If this is attempted, strict adherence to the surgical plane between the transverse mesocolon and pancreas is advised. Noting the slight subtle colour
difference between pancreatic fat and that of the mesocolon should help guide the dissection.
4.2.3.2 The Ureter and Gonadal Vessels
An understanding of embryology is the key to ensuring that injury to the ureter and gonadal vessels is avoided. During development the abdominal musculature encloses the peritoneal “balloon”. Situated behind the balloon are the pancreas, kidneys, adrenal glands, the great vessels and abdominal musculature (e.g. psoas, quadratus lumborum). The gastrointestinal bud enters the abdominal cavity at the neck of the balloon and takes with it a lining of peritoneum—the visceral peritoneum. It exits at the pelvic brim and continues on at the mid rectum. Within the abdominal cavity, ascending, descending and sigmoid colonic visceral peritoneum is very closely apposed to the posterior parietal peritoneum. During medial to lateral dissection, these two layers can be separated, and by staying in the correct plane, the ureter and gonadal vessels remain behind the posterior parietal peritoneum. The ureter can be identified by its vermiculation.
The left ureter can be juxtaposed to the origin of the IMA and may be retracted upwards when lifting this vessel. Consequently before dividing the IMA, it is vital to ensure that the ureter is clearly separated.
Ureteric trauma is possible during pelvic dissection for a ventral rectopexy, deep infiltrating endometriosis or rectal resection. There are slight anatomical variations in the course of the pelvic part of the ureter between males and females. Appreciation of these differences helps towards protecting the ureters. After crossing the pelvic brim at the origin of the external iliac artery, the ureters travel along the pelvic sidewall anterior to the internal iliac vessels. At the ischial spine, they turn medially and enter the bladder base above the pelvic floor. In the male, the ureters are crossed by the ductus deferens. During low rectal mobilisation, keeping the dissection below the seminal vesicles will avoid ureteric injury, as it is at this point that they enter the bladder base. In the female, the ureters are “hidden” beneath the broad ligament and then lie on the surface of the lateral cervical ligaments before entering the bladder base in front of the vaginal fornix. Unfamiliarity of their course can result in ureteric division or obstruction by applying a haemostatic clip for bleeding, for example. Stenting of the ureter can be useful to help identify its course and also protect it against injury. However, this procedure is for the most part unnecessary except in a few key situations.
Stage IV endometriosis
Surgery for local recurrence of cancer
Some cases of benign inflammatory disease
Preoperative ureteric dilatation or obstruction
Known congenital renal abnormality
Single kidney
A recognised ureteric transection may be repaired laparoscopically with sutures if the proximal and distal ends can be united without tension (Video 4.1). This is possible where there has been no or minimal tissue loss and there has been no devascularisation of the ureter and where the site of transection is proximal to the bladder. The stent should remain for at least 6 weeks post repair. If a tension-free primary repair is impossible, then reimplantation using a Boari flap may be necessary, and expert help should be sought.
4.2.3.3 Bladder
Bladder injury is uncommon as it is directly visualised during laparoscopic dissection. Trauma may occur when a port trocar is passed through the bladder. Decompressing the bladder by catheterisation should prevent this and also improves the view of the pelvis and facilitates access and is mandatory for all pelvic surgery. A chronically obstructed bladder is particularly at risk during trocar placement, and care should be taken when inserting suprapubic trocars under direct vision. The bladder is also at risk when making a low transverse suprapubic incision as for specimen extraction during left-sided resection. In all cases, recognition of the injury is the key to avoiding subsequent complications. Injuries to the dome of the bladder should be sutured directly with absorbable sutures making sure the knots are external to the bladder. Integrity of the repair can be tested by filling the bladder via the catheter with sterile water (there is no need to use methylene blue dye). A complex repair benefits from a period of bladder decompression postoperatively. Bladder integrity can be checked by cystography prior to removal of the catheter.
Injuries to the base of the bladder should be very rare. Complex stage IV endometriosis can involve the trigone or bladder wall close to the ureteric orifices. In these cases, specialist urological input is required and preoperative stenting is crucial in allowing a safe bladder repair.
4.3 Postoperative Complications
4.3.1 Anastomotic Leak
Morbidity and mortality following a colorectal anastomotic dehiscence is substantial. A leak following a laparoscopic TME for neoplasia will result in a suboptimal long-term oncological outcome [2]. Restoration of intestinal continuity may not be possible and the patient may be left with a permanent stoma. All steps should be taken to minimise the chances of anastomotic failure, but there will be times that the anastomosis will leak despite adhering to all principles for good anastomotic technique. In situations where a leak is suspected, diagnosis and treatment must be prompt and consideration given to saving the life of the patient and reducing the impact of systemic sepsis as well as potentially “saving the anastomosis” in some situations. Treatment comprises patient support and surgical attention to the leak. This may vary from complete disconnection and an end stoma or primary repair with a defuctioning loop stoma.
4.3.1.1 Identification of Risk Factors
In the preoperative phase, it is vital to identify risk factors that increase the risk for an anastomotic leak (Table 4.1). Male sex, comorbidity (including diabetes), a smoking history, long-term and perioperative steroids, high body mass index and preoperative chemoradiotherapy have been shown to be significant for anastomotic leak [3, 4]. Intraoperative factors include faecal contamination, blood loss of 100 ml or more, multiple firings of the staple gun, a level of anastomosis less than 4 cm and operation time of more than 120 min [5, 6]. Intraoperative episodes of hypotension and should be avoided. In 285 patients undergoing elective left-sided resections, severe hypotension (>40 % from baseline) was a significant factor for anastomotic leak [7]. In 223 patients who had a gastrointestinal anastomosis, dehiscence was three times more likely if a vasopressor had been used for pressure support [8]. Supplemental oxygenation in the intra- and postoperative period for 6 h will have a beneficial effect. In a randomised controlled trial of 80 % oxygen during and 6 h after surgery, the risk of leak decreased by 46 % when compared to those having 30 % oxygen [9]. The role of maintaining normothermia in preventing surgical site infections is established. One study has implied that a higher intraoperative temperature predisposed to anastomotic leak and increased length of hospital stay. However, a type I error may well have occurred as the sample size was small (n = 76) as were the number of leaks [10].
Table 4.1 Risk factors that increase the risk for anastomotic leak
4.3.1.2 Preventive Factors
The bowel ends should be well vascularised and the anastomosis free of tension. Division of the IMA at the origin (high ligation) was thought to be oncologically optimal; however, there is no concrete evidence to suggest a survival advantage with high ligation, although the number of lymph nodes retrieved is better [11]. An analysis of colonic length revealed an insignificant gain from high vs. low ligation (2.9 ± 1.2 cm vs. 3.1 ± 1.8 cm [p = 0.83]). When combined with a high division of the inferior mesenteric vein (IMV), the length increase was significantly greater (19.1 ± 3.8 vs. 8.8 ± 2.9 cm, p = 0.00089) [12]. A high ligation should be considered if a tension-free anastomosis is not attainable with low ligation and division of the IMV or if preoperative radiology suggests more proximal lymph node metastases. If a tension-free anastomosis is not possible even after division of the inferior mesenteric vein, the splenic flexure should be fully mobilised.
Multiple staple firings to transect the mid to low rectum may increase the risk for anastomotic leak. Most rectal transections can be achieved with one or two firings of a 45- or 60-mm stapler if sufficient mobilisation has been undertaken and all the mesorectum divided. Use of a flexible stapling device and introducing the stapler through a suprapubic port can help achieve good transection even in a narrow pelvis.
Orientation of the proximal colon before fashioning the anastomosis is vital in preventing torsion. Ischaemia of the torted segment can occur with subsequent anastomotic dehiscence. To prevent torsion, it is important to ensure that the taeniae coli follow a straight course, usually along the superomedial surface of the left colon (Video 4.2). Once the colorectal anastomosis has been fashioned, tension-relieving sutures across the anastomosis may be helpful in minimising anastomotic leak. There is evidence to show a fivefold reduction in clinical leak
with the technique [13] (Video 4.3). It is also feasible that the anastomosis becomes ischaemic once it has been fashioned. If during laparoscopy the anastomosis is dusky, it is better to redo the anastomosis. The vascularity of bowel on either side of the anastomosis can also be judged for adequacy by intraoperative rigid sigmoidoscopy or colonoscopy. If there is any doubt, then the anastomosis should be refashioned.
4.3.1.3 Diagnosis of Anastomotic Leak
An anastomotic leak should be suspected when the patient exhibits signs of the systemic inflammatory response syndrome (SIRS) on postoperative day 3/4. Other subtle signs include a drop in oxygen saturation, rising respiratory rate, a cardiac arrhythmia, neurological complications such as delirium and worsening abdominal pain and/or distension. The suspicion of a leak must be high with a paralytic ileus that fails to resolve after electrolyte and fluid abnormalities have been corrected. Some have suggested that plasma C-reactive protein (CRP) above 140 mg∙l−1 (on postoperative day 3) is a sensitive and specific surrogate marker for anastomotic leak [14]. Imaging in the form of computerised tomography or Gastrografin enemas are useful, but their interpretation is limited and should be within the context of the clinical signs and symptoms. Early recourse to diagnostic laparoscopy if the suspicion for anastomotic leak is high, irrespective of the findings on radiological imaging. A leak detected early may allow the anastomosis to be preserved and so the threshold for diagnostic laparoscopy should be low. In one systematic review, the sensitivity of computerised tomography (CT) was 68 % [15].
4.3.1.4 Preservation of Anastomosis
There are many ways to attempt to preserve the rectal anastomosis following a leak, but this should not be attempted at the expense of the patient’s overall wellbeing. If the colonic conduit is not ischaemic or necrotic, then an attempt at salvaging the anastomosis is potentially worthwhile. For a low rectal anastomosis, access to a posterior leak via the abdomen may be extremely difficult. One method where access to the leak is facilitated is the transanal approach. Transanal endoscopic microsurgery will allow the anastomosis to be clearly seen and permit suture repair (Video 4.4). Alternatively success has been described with the use of specialised vacuum dressing placed in the leak cavity in conjunction with a defunctioning stoma. Laparoscopy can be employed to deal with intra-abdominal contamination.
4.3.1.5 Postoperative Intestinal Obstruction
A sizeable mesenteric window can occur when the anastomosis has been fashioned. Small bowel loops can pass through the window causing mechanical obstruction. It is an infrequent complication but always requires reoperation to rectify. There is no evidence that closing these defects prevents these rare occurrences. The most common event of this type usually follows a left hemicolectomy where the splenic flexure has been excised and a colo-colonic anastomosis fashioned. This leaves a large mesenteric defect into which the small bowel is prone to herniate. The patients are acutely unwell with small bowel obstruction, and cross-sectional imaging will show dilated small bowel in the left side of the abdomen and the left colon/anastomosis pushed to the right. It is usually also associated with signs of anastomotic leak. Preventive methods include retraction of small bowel from the window with interposition of omentum, if possible. Other means by which obstruction may occur is when small bowel rotates around the proximal limb of a defunctioning loop ileostomy. Suture fixation of the small bowel is of little value as a preventive measure and so is not recommended. Repeat laparoscopy should be considered if postoperative mechanical obstruction is suspected within the first few postoperative days.
Conclusions
Laparoscopic colorectal complications are infrequent but when they occur are potentially serious. The majority of complications are injuries to viscera, organs and vessels with the most significant postoperative one being anastomotic leak from a low rectal anastomosis. Several reasons are responsible for laparoscopic injuries and include the abdominal “blind spot”, ineffective retraction of small bowel, poor technique and insufficient knowledge of anatomy and anatomical variations. Unfamiliarity with instrumentation especially energy sources significantly contribute to intraoperative injuries. Division of vascular pedicles should take into account the vessel diameter, limitations of energy source used and the need for adjuncts such as clips and stapling devices. If major haemorrhage from a vascular pedicle cannot be dealt with laparoscopically, the procedure should be rapidly converted.
Ensuring that the dissection is in the correct anatomical plane, which lies between the colonic mesentery and retroperitoneum, can prevent ureteric injury. It is imperative that the ureter is deemed to be clear when dividing the inferior mesenteric artery. For right colectomies, the ureter does not pose as much of a problem in comparison to the left colectomy, but the duodenum can be injured
during hepatic flexure mobilisation. The energy source used for dissection should be cooled before it is used to handle bowel.
There should be a low threshold for postoperative diagnostic laparoscopy if an anastomotic leak is suspected. The transanal approach may be contemplated if the leak is posterior and amenable to suture repair.
参考：Complications in Laparoscopic Surgery A Guide to Prevention and Management |
