- Introduction
- Investigations
- Penetrating and blast injuries
- Specific abdominal injuries (evaluation and treatment)
- Conclusion
Introduction
Abdominal trauma accounts for up to 20% of trauma-related operations. Geography largely determines the distribution of blunt and penetrating injury, the latter more common in urban areas. While the enforcement of the wearing of seat-belt restraints has seen a reduction in the incidence of head, chest and solid visceral injury, their use is associated with pancreatic, intestinal and mesenteric injury due to compression against the lumbar spine.
Key points:
Important points to abdominal trauma
- Earlier diagnosis and management reduces morbidity and mortality.
- Maintain a high level of suspicion based on history of trauma and related injuries.
General surgeons have an essential role in the immediate resuscitation and decision-making process of multiply injured patients. The abdomen is potentially responsible for major morbidity and death from early haemorrhage and late sepsis. Diagnosis may be obscured by multiple injuries rendering clinical signs inaccurate. Nevertheless several indications for laparotomy exist including:
- penetrating trauma to the abdomen (with breach of the peritoneum),
- hypotension in the face of obvious abdominal trauma, obvious peritonitis, evisceration through a wound (excluding omentum) and
- GI haemorrhage following abdominal trauma.
In most instances however these conditions are not present and clinical assessment aided by investigations must be judiciously used to select those patients who require laparotomy.
While an aggressive laparotomy policy will enable confirmation of the existence of intra-abdominal injury, an unnecessary operation confers a finite risk to all patients including hypothermia and of more concern may divert attention away from injuries deserving higher priority for management. Needless over-investigation and delay where a laparotomy is needed however may also result in greater harm to the patient. The importance of clinical re-assessment to re-evaluate abdominal signs as well as the response to fluid challenge cannot be over emphasized.
The extent of the abdominal cavity is usually underestimated. It extends from the level of the nipple (4th intercostal space) to the perineum. It may be conceptually divided into 3 compartments, the retroperitoneum, the peritoneum and the pelvis, subject to differing patterns of injury and clinical signs. Interpretation of clinical signs pertaining to the abdomen may be rendered inaccurate due to a number of general (e.g. alcohol, head injury) and local factors such as thoracic, abdominal wall and bony pelvic injuries.
Clues to abdominal injury begin with the history. The force of impact in a motor vehicle accident indicates the energy transferred to intra-abdominal viscera. The mechanism of injury is also important. Examination of the abdominally injured is in many cases the most important part of the assessment. It should be thorough including a rectal examination and also should be targeted towards the mechanism of injury and any obvious external signs of injury. These may include bruising seat belt or tyre, hoof marks etc. at the site of impact. For penetrating injuries the entry and exit sites must be carefully evaluated and trajectories must be carefully analysed especially where exit wounds are not found.
Investigations
When laparotomy is not absolutely indicated yet doubt as to the possibility of abdominal trauma still exists, there are several means of further investigation available:
- Ultrasound
- CT scan
- DPL
- Laparoscopy
- Laparotomy
Ultrasound
Provides a means of simple, rapid assessment in the resuscitation bay. The main advantages (over CT) are that it is cheap, safe, mobile and rapid evaluation may be carried out at the bedside and repeated. Limitations, however include operator dependence (expertise in this technique is essential), an inability to assess the extent of visceral damage and a significant rate of missed injury, up to 10% in the best centres. The best results are obtained by centres experienced in trauma, personnel trained in the technique and most importantly reproducibility is maximized by using it as a screening technique where the end-point is the presence of free-fluid within the abdominal cavity. Its greatest value lies in demonstrating a positive finding in a stable patient. An additional advantage is assessing foetal viability in the pregnant patient.
Computed Tomography (CT)
While many units have shown excellent results in terms of sensitivity and specificity for particular findings, it has not been a uniform experience and several variables will influence a particular unit¹s choice of investigation.
Findings which are reliably detected are the presence of free blood / fluid in the peritoneal cavity, solid visceral injury especially liver, spleen. pancreas and kidneys, the presence of free gas as well as small pneumothoraces which may have been missed on supine chest X-rays. While most retroperitoneal injuries will be detected, gastrointestinal perforations may be missed. The absence of free fluid or gas does not exclude a hollow visceral injury and use of enteric contrast may improve sensitivity of detection. It does not give information about the rate of continued blood loss.
The main limitations include the need to transport the patient to the scanner, relative inaccessibility of the patient during scanning and the risk of a patient becoming haemodynamically unstable during transport or scanning. Haemodynamic compromise remains an absolute contraindication to CT scanning. The more widespread use of helical CT scanning has substantially reduced the time taken for the investigation.
Diagnostic Peritoneal Lavage (DPL)
Despite advances in the above imaging modalities, DPL is an important indicator of intra-abdominal injury. Overall accuracy is reported at over 97%. The only absolute contraindication is an established indication for laparotomy. DPL does not indicate the source or volume of haemorrhage nor whether the haemorrhage is ongoing. It will not give information about retroperitoneal injuries and pelvic fractures with haematoma tracking up into the DPL wound site may give a false-positive result. A positive result is an indication for laparotomy.
Technique
1. insertion of naso/oro-gastric tube to decompress the stomach
2. insertion of urinary catheter to empty bladder
3. prepare skin around and below umbilicus
4. use of local anaesthesia (lignocaine 1% with adrenaline)
5. vertical midline incision just below the umbilicus
6. vertical incision through linea alba commencing at the umbilical cicatrix
7. clips applied to the peritoneum prior to incision
8. insertion of a purse-string suture through the peritoneum and linea alba
9. insertion of peritoneal dialysis catheter towards pelvis (if indicated -see below)
10. rapid infusion of 20ml/kg of warmed normal saline. (usually 1000mls in adults)
11. and the patient is rolled side-side, 30 seconds for each.
12. fluid bag is lowered and siphoned from the abdominal cavity.
13. catheter is removed and wound closed.
Placement of the incision may need modification where there are pre-existent scars, pelvic fracture or pregnancy is suspected. Surgical trainees may be taught the technique which is similar to that used for elective laparoscopic procedures, increasing the chance that the procedure is safely and rapidly conducted during the trauma assessment.
The criteria for a positive test include the withdrawal of free blood or enteric contents on opening the peritoneum, the lavage of blood, inability to read typewritten print behind the lavage tubing due to the colour of the haemoserous fluid or a laboratory red cell count of over 100,000 per mL or a white cell count over 500 per mL. Microscopy for organisms or enteric content should be performed. The white cell count may not be elevated if less than 3 hours has elapsed from the time of injury. DPL may lead to a non-therapeutic laparotomy in up to 25% of cases. A greatly elevated amylase may be found in the presence of pancreatic injury of upper gastrointestinal perforation.
Laparoscopy
Increasing use and familiarity of laparoscopic techniques in elective general surgery has lead to widespread availability and use in emergency assessment of trauma to minimize the need for unnecessary laparotomy. General anaesthesia is required and preparation for a trauma laparotomy must be made. It should only be used in the haemodynamically stable patient. Advantages and uses include: confirmation of peritoneal penetration of a stab wound and damage to nearby structures, diaphragmatic injury, ongoing haemorrhage from solid viscera. While examining the entire small bowel and retroperitoneal structures is difficult it is nevertheless possible and may be increasingly utilized in centres with extensive experience in elective advanced laparoscopic procedures.
Exploratory laparotomy
This remains, in certain situations the most effective way of assessing and dealing with intra abdominal injuries. The main indications in blunt trauma are:
Peritonitis: usually due to rupture of a hollow viscus such as the duodenum, intestine, bladder or gallbladder. Free intraperitoneal blood from solid viscus injury or mesenteric vascular injury may also cause significant peritoneal irritation without ongoing haemodynamic compromise. Hypovolaemia / shock - where no other obvious source of blood loss exists. A plain chest radiograph is required to exclude significant haemothorax and a pelvic X-ray will exclude fractures which may give rise to significant bleeding. Other sources of ongoing blood loss such as major limb fractures and scalp lacerations can usually be controlled. Further haemodynamic compromise after short period of initial resuscitation should alert the clinician to the probability of an intra-abdominal source.
Key points:
Safe assessment of abdominal trauma involves
- Adequate history from patient if possible, available witnesses and paramedical staff.
- Repeated measurement of vital signs; HR, BP or saturation.
- Complete physical examination including rectal examination.
- Prompt and correct use of diagnostic investigation.
- Repeated examinations to detect progressive physical signs.
All the above investigations must be utilized in conjunction with, not as a substitute for regular and careful clinical evaluation.
Penetrating and blast injuries
These account for up to 20% of injuries in the UK. Stab wounds are the commonest and even where the peritoneum has been breached will only cause significant damage in 50% of cases. The stabbing victim who is haemodynamically unstable, exhibits peritonism, GI bleeding or evisceration (excepting omental evisceration alone) or continuing external haemorrhage are best dealt with in the operating theatre and will require laparotomy. In the absence of these findings patients may be assessed in the resuscitation room under local anaesthesia to determine direction and depth of penetration of the wound by exploration. Blind probing of wounds should be avoided. Whether the peritoneum has been breached needs to be determined and if this is not possible then laparoscopy may be employed. Where no peritoneal entry is found, wound care is effected and if appropriate, retroperitoneal structures may be assessed by CT scanning using gastrograffin enema contrast as well as intravenous contrast to assess the presence of injury to the renal tract as well as the ascending or descending colon. When the peritoneum has been found to be breached then DPL may select those patients who do not otherwise exhibit a clear indication for immediate laparotomy. Just as effective is frequent, careful serial physical examination to reduce the need for a non-therapeutic laparotomy. Weapons and other objects in situ at assessment should not be removed until the patient is in the operating theatre. Abdominal gunshot wounds and other missile injuries necessitate exploratory laparotomy as visceral damage is almost a certainty (>90%). Missiles will cause tissue damage along the track it makes in its path traversing the tissues. The amount of damage sustained outside the track depends on the amount of excess energy transferred by the missile. High velocity bullets such as those from rifles and machine guns may cause cavitation. A temporary cavity within the tissue destroyed is formed at which time debris may be sucked in. Secondary bone fragments may cause further, more extensive damage. The actual damage sustained is related to a number of variables and it is important to treat not the weapon but the wound. Explosions may cause injury by several mechanisms including blast waves, burns, missile fragments and throwing of victims into the air.
The principles of surgical management include careful, extensive exploration, debridement of devitalized tissues, removal of foreign bodies where access to them does not impart further risk of tissue damage or morbidity, lavage and open management of wounds. Repeated exploration may be required where tissue necrosis may extend and demarcate more clearly and delayed primary closure or healing by secondary intention is usually required. Without careful adherence to these principles wound sepsis is likely to ensue with its attendant mortality and morbidity.
Specific abdominal injuries (evaluation and treatment)
Careful evaluation of the patient with potential intra-abdominal injury begins with a detailed history to elucidate the mechanism of injury, e.g. seatbelt-related, deceleration, direction of impact, speed of impact. Repeated clinical examination supplemented as indicated by the above investigations will lead to detection of the injuries and prevent missed injury resulting in disaster. Particular patterns of injury will direct enquiry towards specific organs:
Right-sided lower rib fracture suggests possible liver injury. Left-sided rib fracture may be associated with splenic or left renal injury. Fracture of the upper lumbar spine (chance) may be associated with duodenal injury and pancreatic neck / body injury with disruption of the main pancreatic duct. A deceleration injury with a seat-belt sign may indicate duodenal transection, mesenteric vascular injury, laceration of small bowel at junctions of fixity / mobility such the duodeno-jejunal flexure and terminal ileum as well as hepatic or splenic damage. Pelvic fracture may have associated bladder, urethral or rectal as well as significant vessel injury. Associated limb / chest and head injury may give clues as to the likely site of abdominal trauma even if signs are not obvious especially in the unconscious patient.
Prior to insertion of naso-gastric tube or urethral catheter signs which may signify a base of skull fracture or partial urethral injury must be excluded. These include periorbital haematoma, epistaxis, clear fluid indicating CSF from nostril, perineal haematoma, and blood at the urethral meatus and a high-riding prostate on rectal examination. Rectal examination is also essential to rule out potential spinal cord injury. The presence or otherwise of bowel sounds and assessment of abdominal girth are useless in the evaluation of trauma.
Key points:
Patterns of injury
The nature of trauma indicates a likely pattern of injury
- Stabbing
- low velocity gunshot
- high velocity gunshot
- blunt impact
- deceleration
Principles of the trauma laparotomy
Operating theatre staff should be informed about a multiply-injured patient and preparation for major vascular and gastrointestinal procedures as well as suction, red cell recycling devices and packs. The surgical team must be prepared for unexpected findings. The patient is positioned supine. A subcostal retraction device (e.g. Goligher or Wynn Jones frame) should be placed and if pelvic trauma is suspected, the legs should be placed in stirrups (Lloyd-Davies or Allen) to allow perineal access and assistant placement. Preparation is from the nipples to midthighs. A generous midline incision should allow exposure of all abdominal viscera. Blood is firstly aspirated and the four quadrants of the abdomen as well as the pelvis are packed carefully. A wide Deaver retractor held by an assistant over a pack placed on the visceral surface of the liver can retract this organ against the diaphragm to compress the organ firmly but gently. A systematic search can be made for specific sites of haemorrhage by removing individual packs sequentially. The liver should be examined finally allowing adequate delay for non-significant haemorrhage to abate. Almost all haemorrhage can be controlled by direct pressure, either digitally or with packs. Torrential haemorrhage can be controlled by direct supracoeliac aortic compression (manually or with an aortic compressor or cross-clamping. Internal control can also be obtained by a distal aortotomy and retrograde passage of a large (e.g. 26G) Foley urinary catheter, inflating the balloon proximally. Once haemorrhage is temporarily controlled, blood and blood products may be infused by the anaesthetic team prior to definitive repair of specific injuries. Once the life-threatening injuries have been dealt with, all other abdominal viscera must be exposed and examined to exclude occult injury. Manoevres to attain exposure include opening the lesser sac, Kocherisation of the duodenum (after mobilization of the hepatic flexure of the colon) to expose the right renal hilum, IVC and head of the pancreas, mobilization of the fourth part of the duodenum to expose the aorta and if indicated, mobilization of the left colon to expose the left renal vascular pedicle. Expanding haematomas should be explored after vascular control has been obtained. Upper abdominal retroperitoneal haematomas should be explored and specialist vascular surgical assistance may be required. Haematomas associated with pelvic fractures should be left intact and controlled by packing, stabilization of fractures by fixation and endovascular embolization following angiography if haemorrhage continues.
Damage control surgery
This concept has arisen by observation of problems which ensue in the multiply injured patient where delay to definitive surgery or prolonged surgery results in hypothermia, acidosis and coagulopathy and multiple organ failure. Rapid control of haemorrhage by packing and stapling of bowel injuries to prevent further peritoneal contamination is all that is effected during the first laparotomy. Stabilization of the patient in the intensive care unit will then allow planning of definitive surgery 24 to 48 hours later. In up to 20% of patients managed in this way, emergency control of haemorrhage may still be required and one of the sequelae may also be abdominal compartment syndrome. This is characterized by rising intra-abdominal pressure leading to anuric renal failure, increasing ventilatory requirements with a rise in airway pressures and eventually carbon dioxide as well as impediment to venous return from the lower limbs.
Trauma in pregnancy
Almost all documented patients suffer blunt injury due to motor vehicle accidents. Up to one third of pregnancies include unsuccessful, abruptio placentae and therapeutic termination being the commonest causes. Approximately half of the foetal deaths occurred during the acute admission period and the majority were directly related to the injury. Maternal Injury severity score and Glasgow coma score are associated with greater likelihood of non-viable pregnancy. Causes of potential foetal death include direct uterine / placental or foetal injury, maternal shock, severe head injury, hypoxaemia and pelvic fracture. Foetal heart rate at admission has not been shown to predict foetal outcome although baseline variability and periodic changes in foetal heart rate are likely to be more predictive of foetal distress. All pregnant trauma patients should undergo pelvic ultrasound examinations to evaluate foetal wellbeing, placental position / abruption. Cardiotocographic monitoring should also take place in association with expert obstetric care. Kleihauer smears should be performed in pregnancy after the first trimester to detect the presence of foeto-maternal transfusion. Administration of Rhesus immune globulin should be considered for all Rh negative patients. The Kleihauer test may be repeated to detect ongoing foeto-maternal haemorrhage and possible foetal exsanguination. Routine plain radiography may be performed with shielding of the pelvis where possible. CT scanning exposes the foetus to between 0.03 and 0.1Gy. This carries a theoretical risk of teratogenesis in the first trimester (during organogenesis) and so DPL may be preferable during this period.
Key points:
Principles of trauma laparotomy
- control bleeding
- control sepsis
definitive surgical management may be delayed 1 or 2 days if patient has gross metabolic derangement. seek further specialist assistance as necessary eg. liver, vascular, urology.
Abdominal wall injury
Blunt injury may give rise to significant abdominal wall injury. Significant bruising or soft tissue damage to the abdominal wall may indicate intra-abdominal injury, but may also simulate the diagnosis of peritonitis and render exclusion of intra-abdominal trauma difficult if not impossible. Pedestrians may be run over by heavy vehicles with resultant shearing of the subcutaneous tissues, devitalizing the overlying skin. Judicious use of early debridement is necessary to prevent the onset of serious necrotizing infection. Debridement includes removal of all visible foreign material and devitalized tissue. Copious lavage with saline should follow. Dressings and repeated debridement may be necessary prior to definitive reconstruction which may involve delayed primary closure, skin grafting or even myocutaneous flaps and synthetic (polypropylene) mesh for significant abdominal wall defects.
Spleen
This is the most commonly injured organ after blunt abdominal trauma principally after motor vehicle accidents. It is a highly vascular but friable organ. A pathologically enlarged spleen is more likely to be injured with lesser degrees of trauma. The extent of injury ranges (Table 9.1) from subcapsular (contained) haematoma through parenchymal fractures which may extend to the hilum to actual avulsion from the vascular pedicle. The spleen is susceptible to deceleration type injury due to its relative mobility between all of its neighbouring attachments. It is at the junction of the attachments that capsular tears occur. Fractures may be caused by contact of the convex diaphragmatic surface against the 9th to 11th ribs. Clues to the presence of splenic injury include a history of deceleration usually involving a motor vehicle accident or a direct blow to the left lower ribs or left upper quadrant of the abdomen. There may be transient hypotension prior to resuscitation and signs of peritoneal irritation maximal in the left upper quadrant of the abdomen may be present. Referred pain to the left shoulder tip due to left hemi-diaphragmatic irritation may be a feature. Plain chest radiographs may reveal fractures of the left 9th to 11th ribs, an elevated left hemidiaphragm and medial displacement of the gastric bubble prior to nasogastric tube insertion. CT scanning remains the mainstay of diagnosis and non-operative assessment of splenic injury. Lacerations appear as low-density irregular bands within the parenchyma. Subcapsular haematomas appear as peripheral low density lesions which flatten the convex contour of the splenic surface.
The risk of overwhelming post-splenectomy infection (OPSI) following splenectomy and the success of several spleen conserving techniques has meant a reduction in the rate of splenectomy in adult blunt trauma. Conservative management may be non-operative or operative conservation of the spleen (or part thereof). The phenomenon of relayed rupture occurs in up to 5% of non operatively managed splenic injuries. Three-quarters of such ruptures occur within 2 weeks of the initial trauma however delayed rupture has been reported years later. Its mechanism is thought to involve liquefaction of a contained haematoma leading to an influx of fluid due to its hyperosmolality. The cavity pressure rises and expands the capsule resulting in rupture and secondary haemorrhage. Splenic cysts which may be symptomatic or be found incidentally on imaging may be associated a history of trauma to the spleen managed non-operatively. Selection of patients for non-operative management (up to 25% of adult splenic trauma) is made in the setting of blunt trauma where splenic injury is an isolated injury or associated injuries don not require operative intervention. Haemodynamic stability persists despite no more than 2 units of blood transfused within the first 24 hours. Non-operative management of splenic injury as seen by CT scanning in the haemodynamically stable patient requires careful selection and monitoring of patients. Patients should be observed closely in a high dependency / surgical intensive care ward. CT scanning is useful to monitor morphological changes in the observation period. If laparotomy is being performed, it should proceed as previously indicated. Once blood and clots have been removed from the peritoneal cavity, the left upper quadrant should be carefully inspected. If clot but no active bleeding is seen, this should be gently removed to display the splenic surface. Omental and other congenital adhesions should be divided to "defuse" the spleen preventing iatrogenic injury. Capsular tears or adherent clots may be visualized and the spleen should be carefully palpated to detect other injuries. The spleen may be left in place if no other injuries are seen and left with a dry pack next to it. After attending to other sites within the abdomen, the pack can be removed and the spleen inspected for ongoing haemorrhage. If active bleeding is present, mobilization of the spleen is mandatory. This must be done with care not to cause further injury. The splenocolic, lienorenal ligaments and lateral adhesions are divided while medial countertraction over a moistened pack is applied over the convex surface of the spleen by the surgeon. The apical short gastric vessels will need to be ligated and divided to achieve full mobility. If the exact site of hilar haemorrhage is hidden by the short gastric vessels, then these may all be ligated and divided. While splenectomy may remain the safest option in cases of major disruption of the splenic substance, approximately 50 - 75% of spleens can be repaired once laparotomy has been indicated. Techniques include partial resection (suturing or stapling), ligation of feeding vessels and compressing the splenic substance within an absorbable (dexon) mesh. Once haemostasis has been obtained the risk of further haemorrhage from the spleen is minuscule (<2%). Haemostatic agents such as topical thrombin or surgical (oxidized cellulose), fibrin glue and argon-beam coagulation are also effective in stopping surface haemorrhage. It is important to completely mobilize the spleen and have access to the vascular pedicle prior to attempts at repair. The death rate from isolated splenic injury should be well under 10%. Patients who have undergone splenectomy, especially children are at risk of developing OPSI principally with encapsulated organisms. This is a result of reduced clearance of organisms from the blood during episodes of bacteraemia, reduced levels of IgM antibodies and reduction in opsonization of encapsulated organisms due to absence of the opsonic factor, tuftsin. Immunization must be carried out post-splenectomy against pneumococcus, meningococcus and haemophilus influenza B.
Liver
Liver injuries are common in the blunt injury setting. Commonly hepatic injury (up to 70%) is discovered on CT scanning and many will be managed non-operatively in specialized units where the surgical team is prepared should sudden potentially life-threatening haemorrhage take place. Injuries associated with haemorrhage rendering laparotomy necessary may often appropriately be managed by perihepatic packing and transferred to a specialist hepatobiliary centre for definitive management once the patient has been stabilized. This is usually the safest approach when massive blood loss and delays have already resulted. Liver injuries may be graded on the basis of the depth of laceration, extent of haemorrhage and the presence of major hepatic venous injury (Table 9.2). Penetrating wounds usually cause abdominal bleeding with minimal tissue destruction whereas high velocity missiles may cause extensive parenchymal damage. Blunt trauma to the upper abdomen or lower right-sided rib cage tends to produce explosive bursts or linear lacerations of the liver surface (Fig. 9.1). Again, significant parenchymal damage often results. Stellate bursts tend to affect the posterior superior segment of the right lobe (Couinaud segment VII) due to its vulnerable location, convex surface, relative fixity and concentration of hepatic mass. Associated shearing forces due to deceleration may cause tearing of the major hepatic veins at their junction with the liver.
The main surgical aims are to control bleeding and debride devitalized tissue. Bleeding from Grade I injuries usually subside spontaneously and do not require operative management. It may be responsible for a falsely positive DPL. Ongoing haemorrhage from Grade II injuries will either respond to packing or will require suture ligation of individual vessels and bile radicles. Grade III injuries may need peri-hepatic packing while the portal triad is controlled and prepared for cross-clamping (the Pringle manoeuvre) which can usually safely be maintained for up to 30 minutes. Once this has been achieved a hepatotomy (tractotomy) may be performed to assist in identifying the source of continued bleeding (usually hepatic veins) which can be suture or clip ligated. Grade IV injuries will eventually require lobar or segmental resection but it may be appropriate to delay formal resection until the patient has been stabilized with interim packing and debridement. Hepatic resection post-acute injury should be minimized and only performed as a life-saving last resort. Bile leaks should be actively sought and repaired and the Pringle manoeuvre may assist in its localization by increasing intra-bile duct pressure upstream. Techniques such as omental plugging of hepatic cavities or raw surfaces and drainage are a useful adjunct. Raw surfaces, after control of significant vessels can often be controlled with the use of argon-beam coagulation which is now available to most hepatobiliary units. Perihepatic packing will usually suffice to control all but the severest forms of hepatic bleeding (grades I - IV), allow the patient to be stabilized in ICU and transferred to a specialized hepatobiliary unit while coagulopathy and hypothermia are corrected. Re-exploration to remove packing and effect definitive treatment can be carried out 24 to 48 hours later.
Grade V injuries with injury to the retrohepatic cava or major hepatic veins may not respond to packing and will then require either insertion of an atrio-caval shunt or total vascular isolation by controlling the infra and supra-hepatic IVC after a Pringle¹s manoeuvre. Re-bleeding from the liver after initial suture ligation will require re-exploration and usually lobectomy. Angiography may provide a useful pre-operative adjunct. The latter procedure is the procedure of choice in the event of haemobilia. Selective angiography may be followed by embolization of the feeding vessel. Mortality following liver trauma depends on associated injuries as well as the extent of hepatic injury. Shock at the time of admission is associated with a 30% mortality rate. The death rate following penetrating trauma is around 1% contrasting with 20%mortality from blunt trauma.
Bile duct and gallbladder
Minor lacerations to the gallbladder may be repaired however in most instances a cholecystectomy will be required. Injuries to the common bile duct or hepatic duct can be closed primarily and decompressed with a T-tube (Fig. 9.2). Transection or avulsion of the common bile duct will require Roux-en-Y choledochojejunostomy (Fig. 9.3).
Stomach
Gastric injuries are more likely to occur as a result of blunt injury in the presence of a distended stomach. This results in a blow-out¹ rupture. Gastric injuries as a result of penetrating trauma must be searched for carefully, with special attention to the posterior surface and the margins of the lesser and greater curvatures where omentum may conceal an injury, clues to which may only be a small haematoma. An exit wound indicating a through and through laceration must be assumed to exist until proven otherwise. These sites must be exposed by opening the lesser sac, aided by the use of dye instilled in the nasogastric tube (e.g. Methylene blue) as well as distal clamping across the pylorus and instillation of air down the nasogastric tube to distend the organ to accentuate small leaks allowing easier recognition and immediate repair. Management of such an injury may require debridement and suture in one or two layers with a continuous, haemostatic suture will usually suffice. Decompression post-operatively by a nasogastric tube is a necessity. Extensive damage to the stomach from a blast injury may require sub-total or total gastrectomy. Stress ulcers are common in the multiply-injured patient post-operatively and anti-secretory agents should be considered.
Duodenum and pancreas
The commonest mode of blunt trauma is sudden deceleration in the presence of a seat-belt restraint. These retroperitoneal, immobile organs are compressed against the lumbar vertebrae during spinal flexion. Duodenal rupture should be suspected from aspiration of blood from the nasogatric tube, retroperitoneal gas or loss of the psoas shadow on plain X-ray. A CT scan with fine cuts through the duodenum and nasogastric gastrograffin contrast may aid in diagnosis where laparotomy is not otherwise indicated. Isolated duodenal injury is rare and partial lacerations with minimal devitalization may be repaired. Nasogastric and external drainage is recommended.
Pancreatic injury may be suspected from elevations in serum amylase, DPL amylase level as well as CT scanning. Assessment of damage to the main pancreatic duct will dictate definitive management. This is usually difficult to assess in the acute setting as either ERCP or MRCP are required. In the absence of major duct injury, suture ligation to control bleeding, omental plugging and drainage are the main management techniques. Where transection of the pancreas (anterior to the lumbar vertebra) has occurred, resection of the tail with or without splenic preservation and roux-en –Y loop drainage of the injured surface of the pancreas and main duct as well as external drainage. External drainage alone may suffice in the acute setting (see damage control). Additional techniques include diversion of the enteric stream away from the duodenum by performance of a duodenal Œdiverticulization¹ or pyloric exclusion with a gastrojejunostomy or triple tube diversion via a gastrostomy, retrograde drainage of the duodenum after primary repair via a jejunostomy and a distal feeding jejunostomy. Upper gastrointestinal injuries including liver injury may be also supported by the use of enteric feeding by tube jejunostomy.
Small intestine
Small intestinal injury is usually amenable to simple suture repair. Where devitalization of small intestine has occurred resection and primary anastomosis if appropriate may be effected. Perforation may be concealed along the mesenteric border and areas may be devascularized due to concomitant mesenteric shearing injuries. Preservation of as much small bowel length as possible is the main surgical principle. Expanding haematomas within the mesentery should be explored. They may be otherwise treated conservatively.
Colonic injuries
The general condition of the patient is paramount in deciding on major issues in colonic injuries. The questions raised are whether a diverting stoma should be created, should primary repair or resection with or without a primary anastomosis be performed. A randomized controlled trial (Sasaki et al) has reported primary repair or resection with anastomosis in penetrating colonic injuries as the treatment of choice. Primary repair may be considered safe in a stable patient with a wound involving less than one third of the colonic circumference, located around the antimesenteric surface if there is no compromise in the vascular supply. If there is gross contamination, peritonitis, a post-injury delay of greater than 8 hours or the patient is shocked, primary repair is to be avoided. Blunt colonic injuries may generally be managed by resection and immediate anastomosis if the patient is otherwise stable. A loop ileostomy or double-barrelled stoma may be indicated and will facilitate operative closure.
Rectal injury
Injuries of the intraperitoneal rectum may be treated as described for colonic injuries. Injuries involving the extraperitoneal rectum need to be carefully assessed prior to surgical treatment. A gastrograffin enema and careful examination under anaesthesia are highly advantageous to planning treatment. The usual causes are pelvic fracture, foreign body, knives or gun shot wounds. Her management principles are usually a defunctioning proximal stoma, debridement and drainage of the wound. The rectal stump may be irrigated to minimize contamination. Direct primary repair is difficult and rarely justified. Sphincter injuries should be managed by a specialist in this field, but will usually require defunctioning debridement and perhaps repair either immediate or delayed. Broad spectrum antibiotics in rectal injury are necessary.
Renal injury
Blunt trauma to the kidneys is common and usually minor requiring no active surgical intervention in 85% of cases. It is usually suspected by the site of injury or presence of associated injuries. Macroscopic haematuria is indicative until proven otherwise. Microscopic haematuria does not require further investigation if it resolves on repeat testing. Haematuria may be absent with severe renal trauma such as avulsion of the vascular pedicle. Usually hypotension and loin tenderness will be present. CT scanning with intravenous contrast is now the investigation of choice and will give anatomical and functional information about both kidneys. Indication for operative exploration include persistent retroperitoneal bleeding, extensive urinary extravasation or non-viable renal parenchyma needing debridement.
The operative approach should commence with vascular control via a midline laparotomy prior to opening Gerota¹s fascia. Perinephric haematomas found at the time of laparotomy should only be explored if they are expanding, pulsatile or pre-operative CT demonstrates urinary extravasation. Injuries not requiring emergency intervention are best dealt with by specialist urological units.
Bladder
Rupture of the bladder is liable to occur in blunt injury when the bladder is full. Intra - or extra peritoneal rupture may occur (the latter in 75% of cases) and may be clinically silent initially. Pre-operative diagnosis is by cystography and repair is followed by at least 10 days of decompression by an indwelling catheter. The anterior wall can be accessed through a midline laparotomy and a posterior wall defect may need to be sutured from within the bladder via an anterior cystotomy. A cystogram (trans-catheter) is performed to exclude a leak prior to catheter removal.
Urethra
When signs of urethral injury are present (blood at the meatus, perineal haematoma and a high riding prostate on rectal examination) a urethrogram should be obtained and specialist urological opinion sought prior to catheter insertion. A suprapubic catheter may need to be inserted but bladder fullness should be confirmed by ultrasound if not obviously palpable to avoid iatrogenic injury to nearby structures.
Pelvic fractures usually cause disruption at the membranous urethra with a high-riding prostate. Suprapubic drainage is the initial management with definitive reconstruction (urethroplasty) usually delayed for 2 - 3 months. The bulbous or penile urethra may be injured by a direct blow to the perineum. Again suprapubic diversion of urine is all that is required initially. A voiding cystourethrogram can be performed to assess the injury radiologically prior to consideration of any definitive intervention.
Male genitalia
Skin loss and testicular rupture with haematoma are the commonest forms of injury. The penis and penile urethra are usually spared. Skin loss can be managed with debridement and skin grafting. An exposed testis can be debrided and protected temporarily in the subcutaneous tissues of the upper thigh. Testicular haematomas are usually managed conservatively unless expanding.
Uterine injury
This is usually in combination with associated rectal or urinary tract injury (e.g. Bladder) and is infrequent. Injury to the fundus can usually be directly repaired. In extensive injuries a hysterectomy may be necessary.
The vaginal cuff may be left open to provide drainage especially if associated injuries are present. Direct trauma to the gravid uterus usually results in foetal death. Haemorrhage from the uterus in late stages of pregnancy may be massive and hysterectomy is usually required after caesarean section.
Pelvic fractures (see also Chapter 00 – Pelvic injuries)
The pelvic ring is comprised of the two innominate bones (ilium, ischium and pubis) and the sacrum. The stability of the pelvic ring relies upon the rigidity of the bones and the integrity of the ligaments that unite the three bony components at the symphysis pubis and the sacroiliac joints. High energy fractures can produce pelvic ring and ligamentous disruption with severe soft tissue and visceral injury. These injuries are usually a result of car, car versus pedestrian or motorcycle crashes.
Pelvic injuries are frequently occult and potentially lethal. They also have a significant association with head injuries, thoracoabdominal injuries (intrathoracic aortic tears), urological injuries, rectal injuries and neurological injuries to lumbosacral nerve roots. Therefore, hypotension may or may not be related to the pelvic fracture when blunt trauma is the mechanism of injury.
Haemorrhage is the most significant complication associated with pelvic fracture. Most bleeding occurs from fracture surfaces and venous tears.
The proximity of the internal iliac artery and accompanying veins to the anterior aspect of the sacroiliac joint and ligaments is responsible for the high incidence of vascular injury and associated haemorrhage.
Injury classification
The pelvic ring can be disrupted from a variety of forces. An anteroposterior compression injury (such as in a frontal collision between a pedestrian and a car) results in opening of the pelvic ring by external rotation of the innominate bones (‘open book fracture’.) This causes disruption of the symphysis pubis and tearing of the posterior ligamentous complex represented by sacroiliac fracture or dislocation. Opening of the pelvic ring places the posterior vascular structures under great stress and can result in significant haemorrhage.
A lateral compression injury (such as in a lateral impact in a road crash) implodes the pelvic ring, causing internal rotation of the hemipelvis. The pubic rami are fractured, and posteriorly there is a severe sacroiliac strain or fracture. This injury compresses the pelvic volume, usually preventing significant haemorrhage.
A shear force can vertically displace the innominate bone, causing pubic rami fractures and sacroiliac disruption. These severe, unstable injuries (such as in a fall or motorcycle crash) cause major soft tissue injury and haemorrhage.
Physical examination must include the flanks, scrotum or vulva, buttocks and perineum, noting any swelling, bruising or laceration. A careful examination of the anus and vagina and the entrance to the urethra should be performed, looking for blood or a laceration suggestive of an open pelvic fracture. Tenderness over the sacroiliac region may signify disruption of the posterior pelvis. Palpation of a high riding prostate and the presence of blood at the urethral meatus are pathognomonic of urethral injury. However, the absence of such findings does not exclude a urethral injury, because the external urethral sphincter may be in spasm, halting the passage of blood from the site of injury.
Mechanical instability of the pelvis is tested by manual manipulation. The anterior superior iliac spines are pushed toward each other to note any motion in internal rotation, then pushed apart to note instability in external rotation. Caution must be exercised when performing this especially in the haemodynamically unstable patient. In such patients, the examination should be performed only once to avoid repeated dislodging of any clots that may have formed in coagulated vessels. One leg may be partly anaesthetic because of sciatic nerve injury. A leg length discrepancy indicates vertical instability.
When appropriate, an AP radiograph of the pelvis should be performed. Any abnormality should be further delineated with pelvic inlet and outlet views that demonstrate the shape of the pelvic ring. CT scanning and three dimensional reconstruction are the best way of visualizing the nature of the injury, however should not be performed in the haemodynamically unstable patient.
Management
The unstable pelvic fracture involves at least two disruptions of the ring.
The pelvis must be temporarily splinted (using skin traction, vacuum splint, pneumatic compression garment or pelvic sling) to reduce haemorrhage, and resuscitation begun with crystalloids.
In haemodynamically unstable patients with unstable pelvic fractures a supraumbilical DPL or ultrasound should be performed first to exclude intraperitoneal haemorrhage as the cause of shock. (If there is intraperitoneal bleeding then this must be dealt with by urgent laparotomy).If these examinations are negative then the fractures should be reduced and an external fixation device applied. This prevents further disruption of coagulated vessels, bleeding from fracture surfaces is reduced and low pressure retroperitoneal bleeding is tamponaded. Haemodynamic stability should now be restored, if this is not the case then bleeding from pelvic arterial vessels may be controlled by angiographic embolisation. Open surgical attempts to gain haemastasis are usually unwise as opening of the pelvic retroperitoneum will decompress tamponaded vessels causing haemorrhage.
External fixation usually involves insertion of iliac crest pins and connection to an interiliac bar that arches over the lower abdomen, but can be swung distally over the thighs if necessary.
Internal fixation in the acute setting is occasionally used but usually limited to reduction and fixation of pubic symphysis diastasis.
Open pelvic ring injuries have a high mortality. Treatment requires through irrigation and debridement of wounds (which should be left open) and pelvic stabilization. A diverting colostomy may be necessary.
Conclusion
Abdominal trauma is one component in the multiply injured patient and priorities for resuscitation and treatment must be developed. Rapid control of intra-abdominal haemorrhage may be required immediately following assessment and stabilization of the airway and breathing components of the initial (primary) survey. Close co-operation between specialties is essential and co-ordination is best carried out by personnel who understand the priorities in treatment as well as the principles of surgical repair of the injuries. All possible significant injuries must be excluded and meticulous secondary survey must minimize chances of missing less immediately life-threatening injuries which may have delayed adverse consequences on the patients outcome. All specialists involved in trauma care should use the EMST/ATLS system of trauma care as a basis for streamlined management of all trauma patients.
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