Overview

Major pelvic hemorrhage can occur in up to 9% of patients undergoing complex abdominopelvic surgery.[1] Posterior to the rectum, the presacral veins are a source of bleeding, and laterally the iliac artery and veins are at risk for injury. Pelvic bleeding must be quickly controlled to avoid the patient becoming hypothermic and coagulopathic. Therefore, when brisk bleeding is noted, quick control with direct pressure or packing is necessary to allow anesthesia providers the opportunity to provide support, including blood and coagulopathic factor replacement. When difficult bleeding is encountered, it is important for the surgeon to communicate as early as possible to to allow time for blood products to be obtained. Bleeding needs to be definitively controlled prior to the creation of an anastomosis to avoid obscuring sites of bleeding. When definitive control is not possible, and especially when the patient is hemodynamically unstable and becoming coagulopathic, packing with betadine-soaked gauze, balloon tamponade, or tissue expanders is indicated, with a planned reoperation in 24–48 hours.[2][3][4] For arterial injuries, interventional radiology may be successful with embolization techniques.[5]

Presacral Hemorrhage

Presacral hemorrhage is not a common event. The incidence is reported to be 3%–9.4%.[6][7][8][9] However, a presacral hemorrhage that is not properly attended to can be life-threatening. During the total mesorectal excision (TME) dissection, when the presacral fascia is violated, basivertebral veins can be lacerated near the opening of the sacral foramina they traverses. A transected vein commonly retracts into the foramen, making bleeding difficult to control.[10]

Presacral bleeding can originate from disruption of the presacral venous plexus or avulsion of the sacral basivertebral veins. The clinical consequences of either of these mechanisms are worsened by three factors that can lead to massive bleeding:[5]

1. The presacral venous plexus and sacral basivertebral veins are devoid of valves, enabling bidirectional blood flow.
2. Numerous veins connect the vertebral venous system with the inferior vena cava below the diaphragm.
3. The lower sacrum is in a significantly more dependent position compared with the lumbar vertebrae in the lithotomy position. The resultant bleeding from a transected presacral vein measuring 2 mm or 4 mm in diameter can reach >100 mL/minute or >1000 mL/minute, respectively.[11]

The rectosacral (Waldeyer’s) fascia. which runs from the fascia propria of the mesorectum to the presacral fascia at the S3/S4 level, also contributes to potential injury of the presacral veins. The insertion of the rectosacral fascia onto the periosteum corresponds to the level of the sacral basivertebral veins. Blunt disruption of the rectosacral fascia or nonanatomical dissection distal to the fascia also can cause accidental laceration of the presacral veins with resultant bleeding.[12]

Regardless whether the procedure is performed via an open or minimally invasive approach, presacral bleeding is best avoided by maintaining clear visual exposure and employing sharp dissection at and below the rectosacral fascia, while remaining in the proper avascular plane. Visualization of this most distal dissection is sometimes improved by first performing the lateral and anterior mesorectal dissection. The rectosacral fascia should be sharply incised. The dissection then continues in a more anterior or ventral direction towards the levator hiatus as the curve of the distal sacrum and coccyx is followed.[9][13]

Patients with a locally advanced rectal carcinoma occasionally demonstrate tumor extension beyond the fascia propria of the posterior mesorectum. When the anterior periosteum appears to be involved, sacrectomy is usually planned and the vertebral venous system is controlled where the vertebral column is transected at the most distally uninvolved interspace and after the specimen is delivered. Alternatively, less invasive disease can require excision of only the presacral fascia or anterior cortex of the upper sacrum to obtain an R0 resection. In these cases, presacral bleeding may not be avoidable. Instead, the bleeding should be anticipated, and the surgeon should prepare the operative field as well as the surgical team to control the bleeding as rapidly and effectively as possible.[1] This preparedness is informed by preoperative magnetic resonance imaging (MRI) and a formal multidisciplinary discussion rather than by an ad hoc intraoperative strategy.

In the case of presacral hemorrhage, ligation of the internal iliac arteries or veins does not lessen the hemorrhage for the anatomic reasons previously cited. In fact, even control of the infrarenal aorta and inferior vena cava will likely not decrease pooling of blood in the presacral veins because the vertebral venous system would remain intact.[6]

Massive presacral bleeding needs to be promptly recognized and is characterized by the following conditions:[5]

• Bleeding that suddenly occurs during mobilization of the distal rectum
• Gushing of blood from the pelvic floor that renders site localization difficult
• Bleeding persists despite significant hypotension or internal iliac artery control

Whenever massive presacral bleeding is encountered during an open procedure, the initial step is direct finger pressure on the site of bleeding and notifying the surgical team, including the anesthesiologist, to prepare for the possibility of profound bleeding. When the bleeding site cannot be controlled in this manner, the posterior pelvis is packed with gauze to halt the hemorrhage.[14] A second suction device is secured on the field ,and adequate illumination with overhead lighting or lighted retractors is ensured. Exposure can be further enhanced by extending the incision to the level of the pubis and removal of the specimen whenever possible. Once the patient has been stabilized, blood products have been made available, and all personnel are adequately readied, the surgeon’s finger or pelvic packing is removed. It is imperative that the bleeding site is localized and the type of bleeding (i.e., presacral venous plexus, sacral basivertebral veins) is determined. The bleeding source is controlled by applying direct pressure using a small cylinder of gauze in the end of a fine clamp (i.e., a "bridge" clamp with a "peanut"). Bleeding from veins of the presacral venous plexus can be suture ligated one-by-one using small (3–0) monofilament sutures that incorporate the presacral fascia, presacral vein, and deep connective tissue. Hemorrhage originating from a sacral basivertebral vein retracted into a sacral foramen requires obliteration using a variety of reported techniques used individually or in combination. These techniques include the following:[1][5][15]

• Biologic tissue (e.g., epiploic appendix, omental scrap, rectus muscle) welding
• Directed coagulation (e.g., argon beam coagulator, electrocautery)
• Focal tamponade (e.g., bone wax, bone cement, hemostatic sponge, matrix hemostatic agent, rectus abdominal muscle graft, IV bag, breast implant, Bakri balloon)
• Hemostatic agents developed for military wounds
• Occlusive metal implants (e.g., thumb tack, helical titanium pins) placement
• Direct suture

A combination of these techniques, such as the combination of the occlusive metal implants with hemostatic agents, may be necessary. IV bags and breast implants or even simple packing with gauze can be extracted through the perineum when the procedure is an abdominoperineal resection. Techniques that are not be used are ligation of the internal iliac artery or internal iliac vein. Ligation of the internal iliac artery can lead to gluteal and vesical necrosis. As many of these venous tributaries drain into the internal iliac vein, ligating this vein can actually lead to increased pressure within the sacral plexus and thus worsen the situation.[1]

Iliac injuries can occur with trocar insertion[16] or during pelvic dissection, which increases the risks when the tumor is bulky or dissection outside of the TME plane is required. Intentional or inadvertent dissection into the pelvic sidewall can result in hemorrhage from branches of the internal iliac vein or artery. For a standard TME procedure, this type of pelvic sidewall bleeding is unusual, but for extended resections of tumors invading outside of the TME plane, this is an expected management challenge. Details of repair are beyond this module for training, and choice of repair will depend on available expertise, the degree of injury, and the exact location of the injury and whether it is an arterial or venous injury. Utilization of a vascular surgery consultant, especially for management of the aorta, external iliac, common iliac, and major veins injuries, is recommended.[17][18]

Overall, when injury occurs during a minimally invasive approach and when bleeding cannot be well controlled and/or visualization is frequently obscured by the bleeding, there should be a low threshold to convert to open surgery with placement of packs. Direct pressure at the bleeding site or proximal and distal compression is recommended for safe, rapid vascular control. Anesthesia should be updated about the risks of potential further blood loss and just as with presacral bleeding, blood products and rapid infusion equipment should be in place before attempting to release vascular control for attempted repair. With proximal and distal compression abating the bleeding and after anesthesia is prepared, a quick release either on the distal or proximal side can assist with localizing the site of vascular injury.[18]

At times, definitive control of venous bleeding can be attained solely with local compression using a small piece of gauze or an absorbable knitted fabric hemostat. If this fails, other techniques such as direct suture ligation and/or repair with 5–0 monofilament ligatures with consideration of pledgets on thin walled veins can be implemented. Other options include argon beam coagulation, biologic tissue welding, focal tamponade, helical tacks, clips, patch angioplasty, and/or end-to-end vascular anastomosis. The latter two are usually performed with significant injury that would result in significant segmental loss of the vein or significant narrowing of the vessel lumen.[17][18]

Arterial bleeding, while more brisk, can be easily addressed with either running or interrupted repair using a fine monofilament suture with a small defect. Larger vessels such as the common iliac and even the aorta are more forgiving with a running repair while smaller arteries with a large defect are best served with interrupted simple sutures to prevent stenosis. Depending on the extent of injury, a polytetrafluoroethylene (PTFE) interposition, PTFE angioplasty, resection, and primary anastomosis may be necessary.[16][17]

After repair, assessing distal perfusion in the lower extremities is imperative. This can be performed by palpation of the distal pulses and/or searching for a doppler signal.