Friday, March 7, 2008

COLORECTAL TRAUMA



Traumatic Colorectal Injuries, Foreign Bodies, and Anal Wounds

COLORECTAL TRAUMA
Trauma-related deaths have a tripartite distribution.
· There are immediate deaths that occur soon after injury and before hospital transport and, typically, in association with major neurologic and cardiovascular injury.
· There are early deaths that occur at and about the time of transfer to the hospital and within a few hours after injury due to major hemorrhage, such as hemorrhage in the chest and abdomen, and due to severe blood loss from multiple, less-specific injuries.
· The third time of trauma death occurs secondary to infection, beginning toward the end of the first week of hospitalization and continuing well into the second and third months after injury.
o Infection, overt sepsis, and multiorgan failure are special problems in colonic injury because of the inevitable bacterial contamination that frequently coexists with hemorrhagic shock.
o In civilian practice in the United States, a gunshot wound to the colon is the most common cause of penetrating injury, with stab wounds being second, and shotgun wounds being third. Blunt trauma occasionally causes colorectal trauma and presents special diagnostic problems

With the increasing use of therapeutic endoscopy that is often performed by nonsurgeons, iatrogenic or unintentional perforation of the colon has become a special problem that deserves separate comment in terms of overall management (see "Iatrogenic Injury"). The frequency of iatrogenic injury, especially in tertiary centers, is vastly underestimated.
Colonic injury, when combined with other injuries such as injuries to the parenchymal organs (i.e., the liver, pancreas, spleen), is especially important in contributing the "second" part of the "two-hit" hypothesis (i.e., bacterial contamination combined with hemorrhagic shock). It therefore has a substantial influence on survival and an even greater effect on infectious morbidity rates.
The major factor in the assessment of patients with colorectal injuries, which is discussed in detail in "Intraoperative Management," depends on the severity of injury, a grading system for both intra-abdominal colon and rectal injuries that is helpful in recognizing the severity of the injury.
All of these factors contribute significantly to the likelihood of infectious complications, and these in turn are closely related to the likelihood of late death.
· For example, there is a steady increase in infectious complications in parallel with the number of units of blood transfused during a laparotomy for colon injury, rising to as much as 60% when more than 10 units of blood have been transfused.
· Similarly and not surprisingly, the risk of infection approaches 100% when more than five organs have been injured, but the risk is only half that when four or fewer organs have been injured.
· Patient age also has a substantial effect on the infectious complications rate. Patients younger than 30 years have only a 12 to 15% infection rate, whereas those older than 30 years have an infection rate of more than 40%.
INITIAL RESUSCITATION AND ASSESSMENT
We believe it is helpful to review the important issues of the basic principles of care of the trauma patient.
· Care of the trauma patient begins at the scene.
· Before transport, the patient must receive basic emergency medical services consideration such as a cervical collar, stabilization with a spinal board, and endotracheal intubation with in-line cervical traction if the patient is not breathing spontaneously.
· Intravenous access should be obtained and crystalloid solutions should be infused during transport.
· Extremity fractures are splinted with pneumatic devices or any other kind of rigid support system.
On arrival at the treatment facility, the old adage of ABC (airway, breathing, and circulation) remains the fundamental catechism of the advanced trauma life support system of the American College of Surgeons.
· The presence of a patent airway must be redefined at every step in the process.
· If intubation is not technically feasible, cricothyrotomy may be required, especially if there has been associated trauma to the head, such as a mid face fracture.
· Correct positioning of the endotracheal tube must be determined with chest films, and intubation of the right main stem bronchus should always be considered if no left-sided breath sounds are heard.
· Hemothorax must be excluded on the basis of chest films and physical examination.
· The adequacy of circulation is determined through a variety of measures, including blood pressure and capillary refill determinations.
· If the patient is hypovolemic, two large-gauge peripheral intravenous lines must be established, and fluids must be infused rapidly, pending the availability of type-specific blood.
Further assessment of individual injuries should be undertaken once the airway is secured, breathing is accomplished, and circulatory resuscitation is under way.
· Penetrating injuries to the abdomen, including ecchymoses, must be noted.
· If an intra-abdominal injury is likely, a broad-spectrum, safe cephalosporin should be administered with one of the first liters of intravenous fluid.
· We continue to believe that the scenario of trauma with shock and resuscitation is ideal for the use of very large doses of safe antibiotics and their continuous infusion.
· As part of the care of the trauma patient, an evaluation of pelvic fractures is especially important with respect to bladder injuries or laceration to the anus or rectum.
· It is important to examine the perineal area and to determine the presence or absence of blood at the urethral meatus or on rectal examination.
· If there is blood at the urinary meatus or if the prostate is not palpable on rectal examination, one must especially consider transection of the urethra, and a urethrogram should be done before Foley catheter insertion.
Depending on the patient's stability, if a pelvic fracture is present, it must be stabilized with an appropriate external fixator or with a military antishock trouser (MAST) device after the Foley catheter has been inserted.
· This will stabilize the fracture and provide some control of the hemorrhage, which may complicate pelvic fractures.
· While resuscitation and the initial assessment are ongoing, the insertion of a nasogastric tube, by either nose or mouth, will permit the detection of blood within the stomach, as well as decompress the patient in preparation to receive an anesthetic agent.
· Any penetrating injury below the level of the nipples must be considered to be a possible intra-abdominal injury.
The evaluation of the abdomen in the unconscious patient continues to represent a real problem; diagnostic peritoneal lavage (DPL) has been a reliable procedure for nearly 3 decades.
· It is performed under direct vision, with care.
· If no gross blood is encountered, lavage of the peritoneal cavity with saline is performed.
· DPL is considered positive and indicative of intra-abdominal injury if the effluent contains more than 100,000 red blood cells/mm3 or more than 500 white blood cells/mm3, with a hematocrit of more than 2, or in the presence of bile, bacteria, and vegetable or fecal matter.
· If DPL is negative but there still is suspicion of intra-abdominal injury, further evaluation by ultrasound examination or computed tomography (CT) scanning may be helpful.
· Ultrasound examination, when carried out by the examining surgeon, is a most efficient, inexpensive, and reliable aid to patient care.
o Ultrasound is steadily replacing DPL and CT studies, and the focused abdominal ultrasound for trauma is rapidly replacing DPL in many institutions.
o Focused abdominal ultrasound includes evaluation of the pericardium, right and left upper quadrants, and pelvis.
The overall priorities of trauma care are important and must be dealt with elsewhere.
SPECIAL DIAGNOSTIC PROBLEMS
· Colorectal injury associated with blunt trauma is especially treacherous and is uncommon enough to worry even the most experienced trauma surgeons.
· It represents only about 1 in 30 such injuries, and the diagnosis is often made only at the time of laparotomy for other injuries.
· The diagnosis will often not have been made, and the surgeon will have to be alert intraoperatively to take appropriate measures.
· Reported data regarding these injuries are suspect in the sense that diagnosis is often delayed and then involves the treatment of a late recognized colon perforation as opposed to the more frequently and promptly diagnosed event when penetrating trauma has occurred.
A further opportunity for diagnostic error regarding injury to the large bowel is the failure to carry out a careful, well-illuminated, and detailed perineal examination in the often unstable multitrauma victim.
· Lacerations in the perineum or into the rectum must be presumed to be associated with open pelvic fractures.
· Shards of bone associated with some pelvic fractures can readily lacerate all pelvic structures, including major blood vessels.
· The careful examination of the perineum and the rectum, including an examination for occult blood, is important in this scenario and can be difficult.
· There is no substitute for a careful examination by a person who is knowledgeable of and especially suspicious of the bizarre ramifications of perineal lacerations and pelvic fractures, in which any part of the genitourinary or alimentary tract may be injured.
· The standard of care often includes the use of sigmoidoscopy, but this can be technically difficult in the trauma patient.
· Triple-contrast CT scanning with intravenous, peroral, and rectal contrast medium can identify many rectal extraperitoneal injuries.
Diagnostic problems occur in several typical scenarios.
· The most common for penetrating trauma is when a retroperitoneal portion of the colon has been injured and the patient presents with few anterior peritoneal signs, no pneumoperitoneum, and symptoms that may be masked by other overt manifestations of trauma or the treatment. Opening of the peritoneal reflection usually discloses the problem.
GENERAL PRINCIPLES OF PREOPERATIVE MANAGEMENT
· The fundamental principles of preoperative management are, of course, securing and maintaining an airway and restoring vital organ perfusion.
· This is ordinarily possible, but there may be circumstances of major vascular injury or liver trauma in which a patient may need to undergo emergency surgery while in overt shock.
· Under these circumstances, the injury to the large bowel is seldom the major contributor to hemorrhage.
· Control of the site of primary blood loss and stabilization of the patient take first priority.
· Resectional d√©bridement of the colon, or its simple stapling, as an early part of a procedure to control contamination while ongoing hemorrhage is being handled may be a wise and proper choice.
· The most significant advance in this field in the past decade has been the recognition that the secure packing of some parenchymal organ injuries often can be the best possible temporizing measure and will allow the patient to return to the operating room in 24 to 48 hours for more definite management of a variety of injuries when he or she is hemodynamically stable, no longer coagulopathic, and warm.
· Notwithstanding the above circumstances of near exsanguination, one of the most important points in the early care of the trauma patient is the intravenous administration of a broad-spectrum antibiotic.
o The agent of choice should be a safe drug such as a second- or third-generation cephalosporin.
o Antibiotic regimens should very seldom include nephrotoxic amino glycosides or unnecessary and occasionally harmful agents aimed at anaerobic bacteria.
o We believe the continuous infusion of a relatively large dose of antibiotics is warranted, given the hemodynamic instability, shock, and transfusion.
o As soon as the condition of the patient has stabilized and contamination is controlled, antibiotics often can be discontinued.
o If contamination is minimal, antibiotics can be discontinued postoperatively.
o If contamination is moderate, an antibiotic should be continued for 72 hours.
o Regardless of the degree of contamination, antibiotic administration should not continue beyond 7 days.
o There is little evidence that the continuation of such drugs for 7, 10, or 14 days accomplishes anything but predisposition to the development of resistant bacterial forms for later infection.
o A summary of our views and practices with respect to the use of antibiotics in colorectal trauma.
INTRAOPERATIVE MANAGEMENT
· If the abdomen is the site of injury, our preferred approach is through a midline abdominal incision.
· We made repeated reference to the need to stabilize the patient intraoperatively and to control or ameliorate ongoing blood loss.
· This is often easier said than done, but when that is accomplished, one is ready to turn attention to the possibly injured colon.
· A system of grading colon injuries is especially helpful to the surgeon (who is not often in this situation) in making a wise choice regarding options, ranging from primary repair to occasional resection and anastomosis, with or without protective proximal stoma.
· Just as the surgeon must begin to make that determination, he or she must constantly be alert to the stability of the patient and the capacity to tolerate a preferred method of repair.
· The choices may include rapid stapling and discarding of a section of colon in a patient with a massive liver injury and multiple transfusions who is being packed to control a major hepatic parenchymal hemorrhage. The other end of the spectrum is represented by a stable patient who has an isolated injury of the lower sigmoid and is an excellent candidate for excision of the injured segment and primary repair in the best of circumstances.
In general, options for the treatment of colon injury include
(1) proximal diversion and repair,
(2) exteriorization of the wound itself as a colostomy,
(3) simple suture of even lengthy colon lacerations, and
(4) resection and anastomosis.
The latter should be applied only with special thought.
· The patient with injuries requiring resection often has associated injuries and therefore is seldom a candidate for an extensive and complex operation and may be better suited for resection and diversion.
· On the other hand, if contamination is not extensive, the patient is hemodynamically stable, and well-vascularized colon is available, then resection and anastomosis may be suitable.
· The algorithm is especially helpful to a surgeon who is unfamiliar with the treatment of colonic injury.
· It is clear that many tangential, and even penetrating, wounds of the colon can be dealt with safely by primary suture in a stable patient.
· Even longitudinal tears can be repaired safely.
· It is quite clear that the procedure of resection and anastomosis in the injured right colon has almost identical mortality and morbidity rates as the more conservative procedure of resection and ileostomy.
· Anastomotic failure is an uncommon phenomenon in the judicious management of right colon injury. provides the main issues of some studies.
Issues
Special dangers of stapled anastomosis in trauma victim
Positive views of primary repair when feasible
Divert if in doubt
Contemporary middle ground


IATROGENIC INJURY
Colonoscopic perforation is remarkably infrequent, and it is clear that many patients tolerate delayed diagnosis and conservative management.
· Failure to consider the possibility of perforation is never an acceptable choice, and when a patient has developed any evidence of instability, abdominal pain, tenderness, or pneumoperitoneum after a colonoscopic procedure, perforation should be assumed to have occurred.
· Unlike the large bowel injury that occurs with trauma, colonoscopic laceration of the colon occurs in a mechanically clean bowel.
· Patients whose signs and symptoms immediately ameliorate with intestinal rest, systemic antibiotics, and volume resuscitation can be treated conservatively without surgery.
· Patients who have continued tachycardia, fever, and leukocytosis and who do not respond to the measures of intestinal rest, systemic antibiotics, and resuscitation require surgery with simple repair of the perforation.
· If the perforation occurs at a site of extensive gross disease, then resection may be in order, and the surgeon can use his or her best judgment as to whether primary anastomosis, with or without a protecting colostomy, is warranted.
Another situation warranting immediate surgery is that associated with the extravasation of barium during the course of radiologic study of the alimentary tract.
· Barium is especially likely to promote and accentuate peritonitis associated with bacterial contamination.
· The mortality rate for barium peritonitis is extremely high.
OTHER TYPES OF COLONIC TRAUMA
Injuries due to foreign bodies are becoming more frequent.
· A wide variety of objects inserted for sexual gratification may be difficult to remove.
· Patients may present late secondary to embarrassment.
· General anesthesia may be required for foreign body removal.
· A relative vacuum may make transanal retrieval very difficult.
· A red rubber or Foley catheter inserted past the object may break the vacuum, facilitating and allowing removal.
· In the case of larger objects or objects that have migrated proximally, laparotomy and colotomy may be necessary.
· Compressed air injury will frequently be associated with pneumoperitoneum and often requires laparotomy to assess the severity of injury and to permit repair or resection.
ANORECTAL INJURY
· Injuries to the intraperitoneal rectum are diagnosed and treated similar to colonic injuries.
· Injuries to the extraperitoneal rectum may be more difficult to diagnose.
· Injuries that are not diagnosed promptly or treated appropriately on postinjury day 1 usually become apparent by virtue of pelvic, perineal, or systemic signs of infection.
· The introduction of appropriate systemic antibiotics is justified by the suspicion that anorectal injury exists.
· Diagnosis is preferably confirmed by an examination (even under anesthesia), rigid sigmoidoscopy, water-soluble contrast study of the rectum, or triple-contrast CT scanning.
· Sigmoidoscopy should be performed if there is blood within the rectum on digital examination or if there is evidence of a bladder or urethral injury, blood within the vagina, severe pelvic fracture, or bullet trajectory above the mid thigh and below the pelvic rim.
· If a rectal injury is suspected, the patient should be positioned in stirrups so there is free access to the perineum.
· In general, if such an injury has been complicated by delayed diagnosis, then diversion is preferred, complemented by the removal of palpable fecal material, rectal "wash-out," and drainage of the presacral space.
· The efficacy of rectal wash-out has not been demonstrated prospectively.
· Rectal wash-out can be performed via sterilized ventilator tubing inserted transanally after anal canal dilation.
· A large Foley catheter (e.g., 24 French) can be inserted into the distal rectum, and irrigation is performed until the effluent is clear. Saline is most frequently used, often with a final irrigation of povodine-iodine.
Contrary to common concepts among trauma surgeons, the promptly diagnosed anorectal injury is often best treated by a definitive early repair, assuming the patient is otherwise stable.
· This in particular applies to lacerations of the anal sphincter and anovular region.
· Obviously, if the patient is badly hurt or in shock or the diagnosis is delayed, diversion becomes part of the care plan for the patient.
· The operating surgeon must be particularly careful that drainage of the area does not produce further sphincter injury.
· It requires the best of the trauma surgeon's overall assessment and the colorectal surgeon's anatomic expertise to optimize results.
Psychologically, the surgeon who plans a colostomy closure of a Hartmann-style stoma must also be ready to perform a major laparotomy, and the patient should be prepared too. Our practice has been to either perform this within 2 weeks or to delay it for 90 days, with a hope of minimizing technical issues and errors.





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