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Injuries to the Abdomen and Pelvis
TRAUMA
that an abdominal injury exists. On arrival in the emergency department, initial examination and resuscitation should proceed simultaneously, following the ABC routine of maintaining an adequate airway and respiratory effort and treating hypovolaemic shock (see Walker, page 202). This may involve supplemental oxygen by mask in the conscious, spontaneously breathing patient, or the use of an oropharyngeal airway, or endotracheal intubation with mechanical ventilation in the unconscious patient. Assessment of air entry into each lung may be followed by insertion of chest tubes to drain air or blood from the pleural spaces. Fluids should be administered via large-bore cannulas into uninjured limbs or groin, inserted percutaneously or by venous cut down at the ankle or cubital fossa. At the same time, continual assessment of pulse, blood pressure and oxygen saturation using a pulse-oximeter is carried out. Initial fluid should be by the rapid infusion of 2 litres of crystalloid, followed by colloid if necessary. Advanced Trauma Life Support® (ATLS®) protocols emphasize the need to control haemorrhage along with fluid replacement, as rapid expansion of the circulating blood volume in patients with ongoing bleeding can be harmful. The use of central lines by inexperienced personnel is not recommended in the emergency room because of the incidence of complications.
Injuries to the Abdomen and Pelvis V Vidyasankar Arun D Pherwani Ray Hannon
Trauma is the leading cause of death in the first few decades of life and the third most common cause of death in all age groups. Abdominal and pelvic injuries contribute to about 20% of fatalities. Experience in the USA suggests that prompt assessment and therapy are best delivered by specialized trauma centres. There are no specialized centres in the UK, therefore all surgeons and surgical trainees must have a thorough knowledge of trauma management. Recently there have been several changes in the epidemiology, diagnostic modalities and therapeutic options in the management of abdominopelvic injuries. This contribution should be read in conjunction with Brooks/Barker, page 190. Blunt trauma is the most common cause of abdominal injury and is usually associated with multisystem injury. Mechanisms of injury include a combination of direct impact, rapid deceleration or shearing and rotational forces. The common causes of blunt trauma are road traffic accidents including ‘seat-belt syndrome’, industrial, sporting and farm injuries. The organs most commonly injured are the spleen, liver and kidney. Internal and external bleeding are the most common manifestations.
Secondary assessment Following initial assessment and resuscitation, a more formal assessment should be carried out, beginning with the history of the incident and a physical examination of the undressed patient. Inspection should include the anterior and posterior abdomen, the lower chest and perineum, followed by a careful log roll to assess the flanks, spine and perineum. Palpation reveals tenderness, guarding or rebound tenderness. Percussion to elicit subtle rebound tenderness and auscultation to determine the presence or absence of bowel sounds are followed by rectal and vaginal or penile examination. Thereafter, a nasogastric tube and a bladder catheter are inserted. In patients with suspected facial fractures, an orogastric rather than nasogastric tube may be inserted because of the risk of intracranial communication. Contraindications to bladder catheterization include blood at the urethral meatus, a high-riding prostate or scrotal haematoma, suggesting injury to the perineal urethra. The lower chest is examined for rib fractures and the pelvis is compressed to exclude bony injury.
Penetrating trauma from gunshot and stab wounds is becoming increasingly common as a result of urban violence. Statistics from the USA suggest that firearm injuries will be a more common cause of death than road traffic accidents by the end of 2003. Gunshot wounds produce varying degrees of injury and tissue destruction depending on the type of weapon, the velocity of the bullet and the distance between the assailant and the victim. Combination injuries: bombs and explosive devices cause a combination of blunt and penetrating injuries, resulting in massive soft tissue injury, blast effect, loss of limbs and life.
Investigations Standard laboratory and plain radiological examinations are carried out. More specific tests that may be required are described below.
Assessment Initial assessment and resuscitation The primary factor in assessing abdominal trauma is not the accurate diagnosis of a specific type of injury, but rather the determination
Arun D Pherwani is a Consultant Vascular Surgeon at the University Hospital of North Staffordshire, Stoke on Trent, UK.
Diagnostic peritoneal lavage has traditionally been the most useful method of assessing abdominal injury and is considered 98% sensitive for detecting intraperitoneal bleeding (Figure 1). It is particularly useful in the assessment of blunt trauma and is also beneficial in assessing penetrating abdominal trauma caused by stab wounds, providing justification for a policy of local wound exploration and observation of gunshot wounds where peritoneal penetration is unclear. It does not detect retroperitoneal injuries.
Ray Hannon is a Consultant Vascular and General Surgeon at the Belfast City Hospital, Belfast, Northern Ireland, UK.
CT is replacing diagnostic peritoneal lavage in stable trauma patients in many institutions. Contrast-enhanced CT gives use-
V Vidyasankar is a Specialist Registrar in Vascular Surgery at the University Hospital of North Staffordshire, Stoke on Trent, UK.
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Intravenous urogram and cystogram are methods of assessing the urinary tract.
Objective criteria for assessing diagnostic peritoneal lavage1
Trauma scoring systems are the final phase of evaluating the severity of injury. They help to provide guidelines for triage and management priorities.
Positive criteria2 Lavage fluid appears in chest drain or bladder catheter • Gross blood on entering abdominal cavity or in lavage fluid (>10 ml) • Red blood cell (RBC) count >100,000/µl (in penetrating trauma: RBC count >50,000/µl) • White blood cell (WBC) count >500/µl3 • Amylase >175 U/ml • Obvious faeces or bile
Management The principles of management are to stop haemorrhage, debride devitalized tissue, repair wounds to the bowel by suture or resection, and to eliminate foreign bodies, haematoma and intes-tinal contents.
Equivocal criteria4 • Dialysis catheter tube fills with blood • RBC count 50,000–100,000/µl (in penetrating trauma: RBC count 25,000–50,000/µl) • WBC count 100–500/µl • Amylase 75–175 U/ml
Preoperative preparation If a significant injury has been confirmed by investigations and/ or the patient is haemodynamically unstable, operative intervention should follow without delay. It is best to control severe haemorrhage surgically, rather than to prolong fluid resuscitation. Broad-spectrum prophylactic antibiotics (metronidazole, 500 mg, plus a second-generation cephalosporin such as cefuroxime, 1.5 g i.v.) should be given promptly to provide aerobic and an aerobic cover. The duration of antibiotic cover should be decided on the basis of intraoperative findings, but cover for more than 72 hours is usually unnecessary.
Negative criteria4 • RBC count <50,000/µlitre (in penetrating trauma: RBC count <25,000/µl) • WBC count <100/µl • Amylase <75 U/ml Results, blunt trauma: false-negative 1.2%, false-positive 0.2%; penetrating trauma: false-negative 3.8%, false-positive 1.0%. 2 Any one positive value warrants laparotomy or CT. 3 High false-positive results if trauma >6 hours 4 Reassess clinically; seek a more senior opinion; repeat lavage in 2 hours; (?) ultrasound, CT. 1
Blunt trauma About 20% of patients with blunt trauma have sufficient physical signs such as continuing hypovolaemia despite adequate resuscitation and progressive abdominal distension to warrant immediate laparotomy. In patients who are stable following initial resuscitation, the results of investigations should guide surgical intervention. Patients with negative ultrasound or diagnostic peritoneal lavage results or those for whom non-operative therapy has been prescribed should be followed up with frequent re-examination and further investigation when indicated.
1
ful anatomical and functional information about several organs. Positive CT scans identify injuries that can be managed nonoperatively, particularly liver injuries. In this context (liver/splenic injuries) limiting CT scans to stable patients with a positive diagnostic peritoneal lavage reduces the numbers, cost and morbidity of unnecessary laparotomies.
Stab wound Following penetrating trauma caused by a stab wound, immediate laparotomy is indicated for evisceration, unexplained blood loss and signs of peritonitis. If the patient is stable and none of the above exist, local exploration of the wound or laparoscopy can be used to determine if the peritoneal cavity has been entered. Superficial wounds require no further treatment, but if peritoneal penetration is confirmed then (depending on the experience of the physician supervising management) the patient should undergo laparotomy or further investigation to confirm the need for laparotomy. A policy of exploration of all stab wounds that penetrate the peritoneal cavity is recommended for surgeons with little experience of these injuries. Fewer than 50% of the patients will have significant intraperitoneal injuries, but negative laparotomy has a low morbidity. The selective policy practised in many centres in the USA and South Africa reduces the number of unnecessary laparotomies and misses fewer than 5% of important injuries, but this policy is best practised by units with large experience of penetrating abdominal trauma.
Ultrasound is being used increasingly as the primary screening technique for blunt abdominal trauma. It accurately detects the presence of free fluid, is inexpensive, non-invasive and can be rapidly and repeatedly performed. Ultrasound is 88% sensitive, 99% specific and 97% accurate for detecting intra-abdominal injuries. In the USA, surgeon-performed focused abdominal sonography for trauma (FAST) has been proved to be rapid and accurate in the assessment of thoracic, abdominal and pelvic trauma. It is used as a rapid method of identifying the peritoneal cavity as the source of haemorrhage in patients deemed too unstable to undergo CT. It is also used to evaluate patients without major risk factors who do not warrant more extensive evaluation. The ATLS® subcommittee of the American College of Surgeons has incorporated ultrasound into the ATLS® curriculum for the assessment of blunt trauma. Laparoscopy: the use of laparoscopy in trauma is evolving. In selected patients with haemodynamic stability and no urgent indication for laparotomy, laparoscopy is useful in determining peritoneal penetration and identifying diaphragmatic injury.
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Gunshot wound Traditionally, exploration of the abdomen has been mandatory 186
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following gunshot wounds, because visceral injuries are generally present if the peritoneal cavity is violated. Many centres now practise a selective policy based on CT findings in stable patients where the imaging suggests an isolated liver injury.
course should have a feeding jejunostomy fashioned and enteral feeding introduced as soon as possible. Laparotomy wounds should be closed using the mass closure technique. If intra-abdominal sepsis is likely, the peritoneal cavity should be irrigated with large volumes of warm saline and the skin wound left open for delayed primary suture. If a series of operations is expected, temporary abdominal closure with a prosthetic sheet may be sufficient and will provide easy access for subsequent procedures. This also helps to avoid the complications of raised intra-abdominal pressure and the abdominal compartment syndrome.
Surgery During exploratory laparotomy, continuous monitoring of the pulse rate, blood pressure, central venous pressure, temperature and oxygen saturation should be carried out. Urine output is monitored through a urinary catheter left in situ, and the stomach is decompressed and emptied by a nasogastric tube. The patient should be placed on a warming blanket on the operating table to prevent hypothermia during the operation. The patient is draped to expose the body from the chin to the knees. A generous midline abdominal incision is advised. This allows extension into the thorax via a median sternotomy or an anterolateral thoracotomy, and access to the upper leg for venous infusion or vein harvest, should the need arise. The surgical priorities are to identify and control major sources of haemorrhage and reduce contamination from perforated viscera by temporary clamping or suturing of injured bowel. • If laparotomy reveals a profuse haemorrhage, the aorta must be quickly compressed at the hiatus. Formal cross-clamping may be required. Venous bleeding can be controlled by pressure and packing. Compression on the edges of a liver laceration and the Pringle’s manoeuvre (compressing the structures in the free edge of the lesser omentum) will control most liver haemorrhage. • The contents of the peritoneal cavity are explored and injuries noted. • The lesser sac is explored through the greater omentum to expose the pancreas and posterior wall of the stomach. • The underside of the diaphragm is inspected along with the adjacent solid organs. • Reflection of the left colon, tail of the pancreas and spleen medially gives excellent access to retroperitoneal structures, the aorta, inferior vena cava, renal vessels and the left kidney. • A similar manoeuvre on the right side reflects the caecum, ascending colon, duodenum and head of the pancreas medially to expose the right kidney and vena cava. • Access to the renal vessels may also be obtained through the base of the mesentery of the transverse colon, lateral to the ligament of Treitz and the duodenojejunal junction. Particular attention must be paid to injuries that are easily missed or overlooked (e.g. posterior wall of the stomach, duodenum and pancreas). All these must be checked for damage and appropriate surgical repair carried out. Patients who develop hypothermia, coagulopathy or acidosis during surgery are unlikely to survive continued efforts at operative haemostasis. Therefore, when there is massive bleeding or contamination (e.g. liver trauma, multiple gunshot wounds), an initial damage control procedure of clearing contamination, and control of gross haemorrhage followed by abdominal packing and temporary closure may be all that should be done. Re-exploration when the patient is stable and normothermic often achieves a satisfactory result. Drainage of the peritoneal cavity is seldom required except for hepatic and pancreatic injury, when it should be of the closed suction type. Patients who are likely to have a prolonged postoperative
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Postoperative management Most deaths caused by blunt or penetrating trauma occur in the first 48 hours following injury. Subsequent morbidity and mortality are usually related to: • abdominal compartment syndrome • intra-abdominal sepsis • anastomotic breakdown • fistula formation • secondary haemorrhage. One of the principal complications of abdominal trauma is multiorgan system failure. This is more likely to occur if injuries are associated with: • abdominal compartment syndrome • prolonged hypotension • massive blood transfusion • sepsis and/or the development of complications. Postoperative management consists of support of organ function and control of sepsis. A ‘second look’ laparotomy may be required. The usual sequence of organ failure is lung, coagulation system, kidney and liver. Early postoperative metabolic and nutritional support helps to preserve perfusion and cellular metabolism. This may be given via the enteral or intravenous route. Nutritional requirements should be geared to match the increased metabolic needs associated with trauma, surgical intervention and septic complications. The early diagnosis and treatment of complications improves prognosis.
Management of specific injuries Diaphragm Injuries to the diaphragm are common following penetrating thoraco-abdominal trauma. In blunt abdominal injury, the left side of the diaphragm is most often ruptured. Diaphragmatic injuries should be repaired at initial laparotomy to avoid the late complication of diaphragmatic hernia. Lacerations should be repaired with interrupted, non-absorbable, mattress sutures. Large diaphragmatic defects should be bridged using a prosthetic mesh. Following repair, abdominal drainage is not required and tube thoracostomy of the affected side should be performed to drain intrathoracic fluid and to obtain full re-expansion of the lung. Stomach Most full-thickness gastric injury results from penetrating trauma. The blood supply to the stomach is excellent and, though considerable blood loss may occur, wounds can usually be debrided and sutured safely with absorbable material in two layers. The stomach contents should be emptied, and decompressed postoperatively 187
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with the nasogastric tube. More severe trauma may require resection with re-establishment of continuity of the bowel depending on the site and extent of the injury.
• proximal pancreatic duct injury • injuries of the head of the pancreas involving the ampulla or the distal bile duct that preclude reconstruction • combined devascularizing injuries to the pancreas and the duodenum. The more complex injuries require an individual approach by an experienced surgeon to assess the possibility of repair and the use of techniques to limit complications resulting from anastomotic breakdown or leakage in the postoperative period. The postoperative course is often difficult and intra-abdominal sepsis and pancreatic and duodenal fistulas are the main complications in patients who survive more than 48 hours. Nutritional support is important and a feeding jejunostomy inserted at the first operation will help to maintain nutrition.
Duodenum Penetrating trauma accounts for about 75% of duodenal injuries, and blunt trauma for 25%. Duodenal injuries are uncommon but are associated with a high morbidity and mortality, usually as a result of delays in diagnosis and management following blunt trauma. A high index of suspicion is important because the symptoms and physical signs may be subtle. If the rupture is retroperitoneal, diagnostic peritoneal lavage will be negative and misleading. The duodenum should be inspected carefully after a Kocher’s manoeuvre. Most duodenal wounds can be closed in two layers. More extensive injuries may be managed using a variety of techniques including closure of the injury with a tube duodenostomy, decompression through a separate incision proximal to the injury, omental or serosal patch, gastroenterostomy and/or duodenal ‘diverticulization’. This technique is described for combined pancreaticoduodenal injuries and includes: • repair of the injury • oversewing of the duodenal stump with insertion of a tube duodenostomy • a gastrojejunostomy • insertion of a T-tube in the common bile duct and institution of external drainage. The most common complications are duodenal fistulas, dehiscence of the repair and intra-abdominal sepsis, each of which has a high mortality. Therefore postoperative drainage of the right subhepatic region and the right paracolic gutter is advocated. The management of duodenal injuries requires skill, good judgement and early referral to specialist care.
Small bowel Small bowel should be inspected at laparotomy from the ligament of Treitz to the ileocaecal valve. Injuries to the small intestine include: • bruises • incisions • lacerations • perforations • mesenteric tears • occasional vascular injury at the root of the mesentery. Simple injuries are closed in two layers, while multiple perforations and lacerations to the bowel and mesentery are best treated with resection and primary anastomosis. Non-viable bowel must be excised. If there is massive intraperitoneal contamination with bowel contents or multiple associated injuries, it may be safer to defunction the bowel by constructing an ileostomy and mucous fistula. Mesenteric haematomas are sometimes associated with perforation of the mesenteric border of the bowel.
Pancreas Pancreatic trauma is relatively uncommon, but has a high morbidity. It may be difficult to manage when penetrating injuries cause associated injury to major vessels (vena cava, portal vein, superior mesenteric vessels), the extrahepatic biliary system and the duodenum. Important determinants of outcome are the magnitude of associated injuries and the presence of injury to the pancreatic duct or duodenum. At laparotomy, any haematoma around the pancreas or lateral border of the duodenum requires full mobilization of the duodenum and pancreas to exclude major injury. Access to the third and fourth parts of the duodenum or superior mesenteric vessels can be improved by mobilizing the right colon, small bowel mesentery and sweeping the viscera to the left. The posterior aspect of the body and tail of the pancreas can be visualized by mobilizing and reflecting the spleen. If pancreatic trauma is found, it is important to assess the integrity of the pancreatic duct. On-table pancreaticography is the most suitable method. Parenchymal injuries of the distal pancreas should be treated by drainage of the lesser sac using sump or closed-suction drains. Severe injuries of the body and tail as well as ductal injuries may be managed by distal pancre-atectomy in a stable patient. Injuries of the head of the pancreas that do not involve the duct, adjacent vessels, ducts or organs may be managed by appropriate surgical drainage. Pancreaticoduodenal resection is indicated for:
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Colon Colonic injuries are usually caused by penetrating trauma and are associated with a mortality of about 10%. Management of colonic injuries involves primary closure of the colonic wound, defunctioning colostomy or exteriorization of the repair, but controversy exists over when to use each technique. It has been customary to teach that left-sided colonic injuries require exteriorization of some form and are inherently more dangerous than right-sided wounds; this is not necessarily the case. Several studies have shown that colostomy formation is associated with a higher complication rate than equivalent wounds treated by primary repair. Non-destructive lesions should be closed primarily, independent of their location. With the more destructive colonic injuries requiring resection, in the absence of shock, preexisting medical conditions, major associated injuries or peritonitis it would seem reasonable to perform primary anastomotic repair, the alternatives being a defunctioning stoma with either a mucous fistula or a Hartmann’s procedure. For injuries to the right colon, a hemicolectomy and ileotransverse anastomosis provide good results. Exteriorization of a colonic repair appears to have few advocates. Spleen The spleen is the most common solid organ to be injured in blunt trauma. Given its important immunological and reticulo188
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endothelial functions, attempts should be made to salvage and preserve the spleen in children, adolescents and young adults, especially if the damage is minor. The spleen is inspected following mobilization and temporary haemostasis obtained by occluding the splenic pedicle. In small, inexperienced centres where help is not always at hand, exploration of all splenic injuries may be the safest course of action. Superficial capsular and parenchymal lacerations may be controlled by pressure, packing, electrocautery or suture. Deeper lacerations may be treated by partial splenectomy. If parenchymal injury is more severe or haemorrhage is a problem and if there is haemodynamic instability or associated major injury, splenectomy is advised. Patients should be treated with antibiotics during convalescence and given polyvalent pneumococcal vaccine before discharge to help prevent overwhelming post-splenectomy sepsis. Splenorrhaphy is possible in about 50% of patients undergoing laparotomy for splenic trauma and splenic re-implantation may be possible following control of immediate haemorrhage. Non-operative management for splenic trauma should be pursued only if there is: • absolute haemodynamic stability • minimal abdominal physical signs • negative diagnostic peritoneal lavage • blood transfusion requirement of <2 units. Stable patients with perisplenic haematoma should be managed conservatively, with clinical and radiological follow-up (i.e. vital parameters, abdominal findings, transfusion requirements coupled with repeated ultrasound/CT investigation.
often helpful. Early operative intervention is necessary for nonfunctioning kidneys before renal vein thrombosis supervenes or for profuse haemorrhage. Renal salvage is possible following most blunt and penetrating injuries. Injuries to the renal pedicle carry the greatest morbidity. Renal and ureteral injuries should be drained following repair. Vascular The principal feature of major vascular injury in the abdomen is haemorrhage and hypotension. Major haemorrhage is also the main cause of immediate death following blunt and penetrating injury. The principles of management are the same as for elective vascular surgery in that proximal and distal control of the vessel is required on either side of the injury. The aorta may be controlled initially by a transthoracic approach to the descending thoracic aorta or by encircling the abdominal aorta as it passes through the hiatus. Vena caval injury should be controlled by direct pressure because mobilization can tear lumbar veins. With haemorrhage under control, damage can be inspected. Major vessels should be explored by reflecting the viscera rather than dissecting into haematomas. Injured arteries should be debrided to remove damaged intima and repaired by primary suture, venous patch, venous onlay graft or the use of autogenous artery. Synthetic prosthesis should be avoided if the peritoneum has been contaminated. Penetrating injuries of the infrarenal vena cava should be treated by repair of both the posterior and anterior wall, the former being accomplished by suture inside the vessel. Retrohepatic vena caval injuries are difficult to treat and are usually fatal.
Liver The liver is the most common organ injured following penetrating trauma. Injuries range from simple capsular avulsion or tear, which requires little operative management, to retrohepatic vena cava injury associated with bilobar parenchymal disruption, which is often rapidly fatal. There is a shift towards non-operative management of isolated liver injuries. The basic principles in the management of hepatic trauma are control of haemorrhage, removal of devitalized tissue and perihepatic drainage. The basic techniques useful in operative management include: • in-flow occlusion • suture • packing with closure and planned re-exploration • hepatic artery ligation • resection • mesh hepatorrhaphy • atrial-caval shunting (a shunt placed between the infrahepatic vena cava and the right atrium that allows exclusion, visualization and subsequent repair of major hepatic vein injuries). The anatomy of the liver and the distribution and pattern of injuries permit separation of the role of each of these approaches. Mortality from hepatic injuries is about 10% and the most common cause of death is shock and transfusion coagulopathy in the perioperative period. Sepsis is the most common complication.
Pelvis Fractures: haemorrhage from a pelvic fracture may be sufficient to defeat resuscitation until the pelvis has been stabilized by external fixation. Angiography and embolization may be indicated if haemodynamic instability persists despite resuscitation and pelvic fixation. Pelvic fractures are associated with high mortality and morbidity rates. Urinary bladder: intraperitoneal rupture of the bladder must be repaired in two layers and suprapubic or urethral drainage maintained postoperatively. Extraperitoneal rupture may be treated effectively with bladder drainage alone. Perineal injuries: the basic principles of surgical treatment are: • urinary diversion by a suprapubic cystostomy for urogenital lesions • faecal diversion by terminal colostomy for rectal/ano-sphincteric lesions • debridement and drainage of contaminated soft tissue and connective tissue spaces • conservative debridement of the margins of the anal or urethral wounds. u
Renal Haematuria should be investigated with intravenous pyelogram to exclude renal trauma or bladder rupture. If either kidney is not visualized, emergency angiography should be carried out to assess the renal vessels and their function; contrast CT is
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FURTHER READING Navsaria P H, Bunting M, Omoshoro-Jones J, Nicol A J, Kahn D. Temporary closure of open abdominal wounds by the modified sandwichvacuum pack technique. Br J Surg 2003; 90(6): 718–22.
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that an abdominal injury exists. On arrival in the emergency department, initial examination and resuscitation should proceed simultaneously, following the ABC routine of maintaining an adequate airway and respiratory effort and treating hypovolaemic shock (see Walker, page 202). This may involve supplemental oxygen by mask in the conscious, spontaneously breathing patient, or the use of an oropharyngeal airway, or endotracheal intubation with mechanical ventilation in the unconscious patient. Assessment of air entry into each lung may be followed by insertion of chest tubes to drain air or blood from the pleural spaces. Fluids should be administered via large-bore cannulas into uninjured limbs or groin, inserted percutaneously or by venous cut down at the ankle or cubital fossa. At the same time, continual assessment of pulse, blood pressure and oxygen saturation using a pulse-oximeter is carried out. Initial fluid should be by the rapid infusion of 2 litres of crystalloid, followed by colloid if necessary. Advanced Trauma Life Support® (ATLS®) protocols emphasize the need to control haemorrhage along with fluid replacement, as rapid expansion of the circulating blood volume in patients with ongoing bleeding can be harmful. The use of central lines by inexperienced personnel is not recommended in the emergency room because of the incidence of complications.
Injuries to the Abdomen and Pelvis V Vidyasankar Arun D Pherwani Ray Hannon
Trauma is the leading cause of death in the first few decades of life and the third most common cause of death in all age groups. Abdominal and pelvic injuries contribute to about 20% of fatalities. Experience in the USA suggests that prompt assessment and therapy are best delivered by specialized trauma centres. There are no specialized centres in the UK, therefore all surgeons and surgical trainees must have a thorough knowledge of trauma management. Recently there have been several changes in the epidemiology, diagnostic modalities and therapeutic options in the management of abdominopelvic injuries. This contribution should be read in conjunction with Brooks/Barker, page 190. Blunt trauma is the most common cause of abdominal injury and is usually associated with multisystem injury. Mechanisms of injury include a combination of direct impact, rapid deceleration or shearing and rotational forces. The common causes of blunt trauma are road traffic accidents including ‘seat-belt syndrome’, industrial, sporting and farm injuries. The organs most commonly injured are the spleen, liver and kidney. Internal and external bleeding are the most common manifestations.
Secondary assessment Following initial assessment and resuscitation, a more formal assessment should be carried out, beginning with the history of the incident and a physical examination of the undressed patient. Inspection should include the anterior and posterior abdomen, the lower chest and perineum, followed by a careful log roll to assess the flanks, spine and perineum. Palpation reveals tenderness, guarding or rebound tenderness. Percussion to elicit subtle rebound tenderness and auscultation to determine the presence or absence of bowel sounds are followed by rectal and vaginal or penile examination. Thereafter, a nasogastric tube and a bladder catheter are inserted. In patients with suspected facial fractures, an orogastric rather than nasogastric tube may be inserted because of the risk of intracranial communication. Contraindications to bladder catheterization include blood at the urethral meatus, a high-riding prostate or scrotal haematoma, suggesting injury to the perineal urethra. The lower chest is examined for rib fractures and the pelvis is compressed to exclude bony injury.
Penetrating trauma from gunshot and stab wounds is becoming increasingly common as a result of urban violence. Statistics from the USA suggest that firearm injuries will be a more common cause of death than road traffic accidents by the end of 2003. Gunshot wounds produce varying degrees of injury and tissue destruction depending on the type of weapon, the velocity of the bullet and the distance between the assailant and the victim. Combination injuries: bombs and explosive devices cause a combination of blunt and penetrating injuries, resulting in massive soft tissue injury, blast effect, loss of limbs and life.
Investigations Standard laboratory and plain radiological examinations are carried out. More specific tests that may be required are described below.
Assessment Initial assessment and resuscitation The primary factor in assessing abdominal trauma is not the accurate diagnosis of a specific type of injury, but rather the determination
Arun D Pherwani is a Consultant Vascular Surgeon at the University Hospital of North Staffordshire, Stoke on Trent, UK.
Diagnostic peritoneal lavage has traditionally been the most useful method of assessing abdominal injury and is considered 98% sensitive for detecting intraperitoneal bleeding (Figure 1). It is particularly useful in the assessment of blunt trauma and is also beneficial in assessing penetrating abdominal trauma caused by stab wounds, providing justification for a policy of local wound exploration and observation of gunshot wounds where peritoneal penetration is unclear. It does not detect retroperitoneal injuries.
Ray Hannon is a Consultant Vascular and General Surgeon at the Belfast City Hospital, Belfast, Northern Ireland, UK.
CT is replacing diagnostic peritoneal lavage in stable trauma patients in many institutions. Contrast-enhanced CT gives use-
V Vidyasankar is a Specialist Registrar in Vascular Surgery at the University Hospital of North Staffordshire, Stoke on Trent, UK.
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185
© 2003 The Medicine Publishing Company Ltd
TRAUMA
Intravenous urogram and cystogram are methods of assessing the urinary tract.
Objective criteria for assessing diagnostic peritoneal lavage1
Trauma scoring systems are the final phase of evaluating the severity of injury. They help to provide guidelines for triage and management priorities.
Positive criteria2 Lavage fluid appears in chest drain or bladder catheter • Gross blood on entering abdominal cavity or in lavage fluid (>10 ml) • Red blood cell (RBC) count >100,000/µl (in penetrating trauma: RBC count >50,000/µl) • White blood cell (WBC) count >500/µl3 • Amylase >175 U/ml • Obvious faeces or bile
Management The principles of management are to stop haemorrhage, debride devitalized tissue, repair wounds to the bowel by suture or resection, and to eliminate foreign bodies, haematoma and intes-tinal contents.
Equivocal criteria4 • Dialysis catheter tube fills with blood • RBC count 50,000–100,000/µl (in penetrating trauma: RBC count 25,000–50,000/µl) • WBC count 100–500/µl • Amylase 75–175 U/ml
Preoperative preparation If a significant injury has been confirmed by investigations and/ or the patient is haemodynamically unstable, operative intervention should follow without delay. It is best to control severe haemorrhage surgically, rather than to prolong fluid resuscitation. Broad-spectrum prophylactic antibiotics (metronidazole, 500 mg, plus a second-generation cephalosporin such as cefuroxime, 1.5 g i.v.) should be given promptly to provide aerobic and an aerobic cover. The duration of antibiotic cover should be decided on the basis of intraoperative findings, but cover for more than 72 hours is usually unnecessary.
Negative criteria4 • RBC count <50,000/µlitre (in penetrating trauma: RBC count <25,000/µl) • WBC count <100/µl • Amylase <75 U/ml Results, blunt trauma: false-negative 1.2%, false-positive 0.2%; penetrating trauma: false-negative 3.8%, false-positive 1.0%. 2 Any one positive value warrants laparotomy or CT. 3 High false-positive results if trauma >6 hours 4 Reassess clinically; seek a more senior opinion; repeat lavage in 2 hours; (?) ultrasound, CT. 1
Blunt trauma About 20% of patients with blunt trauma have sufficient physical signs such as continuing hypovolaemia despite adequate resuscitation and progressive abdominal distension to warrant immediate laparotomy. In patients who are stable following initial resuscitation, the results of investigations should guide surgical intervention. Patients with negative ultrasound or diagnostic peritoneal lavage results or those for whom non-operative therapy has been prescribed should be followed up with frequent re-examination and further investigation when indicated.
1
ful anatomical and functional information about several organs. Positive CT scans identify injuries that can be managed nonoperatively, particularly liver injuries. In this context (liver/splenic injuries) limiting CT scans to stable patients with a positive diagnostic peritoneal lavage reduces the numbers, cost and morbidity of unnecessary laparotomies.
Stab wound Following penetrating trauma caused by a stab wound, immediate laparotomy is indicated for evisceration, unexplained blood loss and signs of peritonitis. If the patient is stable and none of the above exist, local exploration of the wound or laparoscopy can be used to determine if the peritoneal cavity has been entered. Superficial wounds require no further treatment, but if peritoneal penetration is confirmed then (depending on the experience of the physician supervising management) the patient should undergo laparotomy or further investigation to confirm the need for laparotomy. A policy of exploration of all stab wounds that penetrate the peritoneal cavity is recommended for surgeons with little experience of these injuries. Fewer than 50% of the patients will have significant intraperitoneal injuries, but negative laparotomy has a low morbidity. The selective policy practised in many centres in the USA and South Africa reduces the number of unnecessary laparotomies and misses fewer than 5% of important injuries, but this policy is best practised by units with large experience of penetrating abdominal trauma.
Ultrasound is being used increasingly as the primary screening technique for blunt abdominal trauma. It accurately detects the presence of free fluid, is inexpensive, non-invasive and can be rapidly and repeatedly performed. Ultrasound is 88% sensitive, 99% specific and 97% accurate for detecting intra-abdominal injuries. In the USA, surgeon-performed focused abdominal sonography for trauma (FAST) has been proved to be rapid and accurate in the assessment of thoracic, abdominal and pelvic trauma. It is used as a rapid method of identifying the peritoneal cavity as the source of haemorrhage in patients deemed too unstable to undergo CT. It is also used to evaluate patients without major risk factors who do not warrant more extensive evaluation. The ATLS® subcommittee of the American College of Surgeons has incorporated ultrasound into the ATLS® curriculum for the assessment of blunt trauma. Laparoscopy: the use of laparoscopy in trauma is evolving. In selected patients with haemodynamic stability and no urgent indication for laparotomy, laparoscopy is useful in determining peritoneal penetration and identifying diaphragmatic injury.
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Gunshot wound Traditionally, exploration of the abdomen has been mandatory 186
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following gunshot wounds, because visceral injuries are generally present if the peritoneal cavity is violated. Many centres now practise a selective policy based on CT findings in stable patients where the imaging suggests an isolated liver injury.
course should have a feeding jejunostomy fashioned and enteral feeding introduced as soon as possible. Laparotomy wounds should be closed using the mass closure technique. If intra-abdominal sepsis is likely, the peritoneal cavity should be irrigated with large volumes of warm saline and the skin wound left open for delayed primary suture. If a series of operations is expected, temporary abdominal closure with a prosthetic sheet may be sufficient and will provide easy access for subsequent procedures. This also helps to avoid the complications of raised intra-abdominal pressure and the abdominal compartment syndrome.
Surgery During exploratory laparotomy, continuous monitoring of the pulse rate, blood pressure, central venous pressure, temperature and oxygen saturation should be carried out. Urine output is monitored through a urinary catheter left in situ, and the stomach is decompressed and emptied by a nasogastric tube. The patient should be placed on a warming blanket on the operating table to prevent hypothermia during the operation. The patient is draped to expose the body from the chin to the knees. A generous midline abdominal incision is advised. This allows extension into the thorax via a median sternotomy or an anterolateral thoracotomy, and access to the upper leg for venous infusion or vein harvest, should the need arise. The surgical priorities are to identify and control major sources of haemorrhage and reduce contamination from perforated viscera by temporary clamping or suturing of injured bowel. • If laparotomy reveals a profuse haemorrhage, the aorta must be quickly compressed at the hiatus. Formal cross-clamping may be required. Venous bleeding can be controlled by pressure and packing. Compression on the edges of a liver laceration and the Pringle’s manoeuvre (compressing the structures in the free edge of the lesser omentum) will control most liver haemorrhage. • The contents of the peritoneal cavity are explored and injuries noted. • The lesser sac is explored through the greater omentum to expose the pancreas and posterior wall of the stomach. • The underside of the diaphragm is inspected along with the adjacent solid organs. • Reflection of the left colon, tail of the pancreas and spleen medially gives excellent access to retroperitoneal structures, the aorta, inferior vena cava, renal vessels and the left kidney. • A similar manoeuvre on the right side reflects the caecum, ascending colon, duodenum and head of the pancreas medially to expose the right kidney and vena cava. • Access to the renal vessels may also be obtained through the base of the mesentery of the transverse colon, lateral to the ligament of Treitz and the duodenojejunal junction. Particular attention must be paid to injuries that are easily missed or overlooked (e.g. posterior wall of the stomach, duodenum and pancreas). All these must be checked for damage and appropriate surgical repair carried out. Patients who develop hypothermia, coagulopathy or acidosis during surgery are unlikely to survive continued efforts at operative haemostasis. Therefore, when there is massive bleeding or contamination (e.g. liver trauma, multiple gunshot wounds), an initial damage control procedure of clearing contamination, and control of gross haemorrhage followed by abdominal packing and temporary closure may be all that should be done. Re-exploration when the patient is stable and normothermic often achieves a satisfactory result. Drainage of the peritoneal cavity is seldom required except for hepatic and pancreatic injury, when it should be of the closed suction type. Patients who are likely to have a prolonged postoperative
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Postoperative management Most deaths caused by blunt or penetrating trauma occur in the first 48 hours following injury. Subsequent morbidity and mortality are usually related to: • abdominal compartment syndrome • intra-abdominal sepsis • anastomotic breakdown • fistula formation • secondary haemorrhage. One of the principal complications of abdominal trauma is multiorgan system failure. This is more likely to occur if injuries are associated with: • abdominal compartment syndrome • prolonged hypotension • massive blood transfusion • sepsis and/or the development of complications. Postoperative management consists of support of organ function and control of sepsis. A ‘second look’ laparotomy may be required. The usual sequence of organ failure is lung, coagulation system, kidney and liver. Early postoperative metabolic and nutritional support helps to preserve perfusion and cellular metabolism. This may be given via the enteral or intravenous route. Nutritional requirements should be geared to match the increased metabolic needs associated with trauma, surgical intervention and septic complications. The early diagnosis and treatment of complications improves prognosis.
Management of specific injuries Diaphragm Injuries to the diaphragm are common following penetrating thoraco-abdominal trauma. In blunt abdominal injury, the left side of the diaphragm is most often ruptured. Diaphragmatic injuries should be repaired at initial laparotomy to avoid the late complication of diaphragmatic hernia. Lacerations should be repaired with interrupted, non-absorbable, mattress sutures. Large diaphragmatic defects should be bridged using a prosthetic mesh. Following repair, abdominal drainage is not required and tube thoracostomy of the affected side should be performed to drain intrathoracic fluid and to obtain full re-expansion of the lung. Stomach Most full-thickness gastric injury results from penetrating trauma. The blood supply to the stomach is excellent and, though considerable blood loss may occur, wounds can usually be debrided and sutured safely with absorbable material in two layers. The stomach contents should be emptied, and decompressed postoperatively 187
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with the nasogastric tube. More severe trauma may require resection with re-establishment of continuity of the bowel depending on the site and extent of the injury.
• proximal pancreatic duct injury • injuries of the head of the pancreas involving the ampulla or the distal bile duct that preclude reconstruction • combined devascularizing injuries to the pancreas and the duodenum. The more complex injuries require an individual approach by an experienced surgeon to assess the possibility of repair and the use of techniques to limit complications resulting from anastomotic breakdown or leakage in the postoperative period. The postoperative course is often difficult and intra-abdominal sepsis and pancreatic and duodenal fistulas are the main complications in patients who survive more than 48 hours. Nutritional support is important and a feeding jejunostomy inserted at the first operation will help to maintain nutrition.
Duodenum Penetrating trauma accounts for about 75% of duodenal injuries, and blunt trauma for 25%. Duodenal injuries are uncommon but are associated with a high morbidity and mortality, usually as a result of delays in diagnosis and management following blunt trauma. A high index of suspicion is important because the symptoms and physical signs may be subtle. If the rupture is retroperitoneal, diagnostic peritoneal lavage will be negative and misleading. The duodenum should be inspected carefully after a Kocher’s manoeuvre. Most duodenal wounds can be closed in two layers. More extensive injuries may be managed using a variety of techniques including closure of the injury with a tube duodenostomy, decompression through a separate incision proximal to the injury, omental or serosal patch, gastroenterostomy and/or duodenal ‘diverticulization’. This technique is described for combined pancreaticoduodenal injuries and includes: • repair of the injury • oversewing of the duodenal stump with insertion of a tube duodenostomy • a gastrojejunostomy • insertion of a T-tube in the common bile duct and institution of external drainage. The most common complications are duodenal fistulas, dehiscence of the repair and intra-abdominal sepsis, each of which has a high mortality. Therefore postoperative drainage of the right subhepatic region and the right paracolic gutter is advocated. The management of duodenal injuries requires skill, good judgement and early referral to specialist care.
Small bowel Small bowel should be inspected at laparotomy from the ligament of Treitz to the ileocaecal valve. Injuries to the small intestine include: • bruises • incisions • lacerations • perforations • mesenteric tears • occasional vascular injury at the root of the mesentery. Simple injuries are closed in two layers, while multiple perforations and lacerations to the bowel and mesentery are best treated with resection and primary anastomosis. Non-viable bowel must be excised. If there is massive intraperitoneal contamination with bowel contents or multiple associated injuries, it may be safer to defunction the bowel by constructing an ileostomy and mucous fistula. Mesenteric haematomas are sometimes associated with perforation of the mesenteric border of the bowel.
Pancreas Pancreatic trauma is relatively uncommon, but has a high morbidity. It may be difficult to manage when penetrating injuries cause associated injury to major vessels (vena cava, portal vein, superior mesenteric vessels), the extrahepatic biliary system and the duodenum. Important determinants of outcome are the magnitude of associated injuries and the presence of injury to the pancreatic duct or duodenum. At laparotomy, any haematoma around the pancreas or lateral border of the duodenum requires full mobilization of the duodenum and pancreas to exclude major injury. Access to the third and fourth parts of the duodenum or superior mesenteric vessels can be improved by mobilizing the right colon, small bowel mesentery and sweeping the viscera to the left. The posterior aspect of the body and tail of the pancreas can be visualized by mobilizing and reflecting the spleen. If pancreatic trauma is found, it is important to assess the integrity of the pancreatic duct. On-table pancreaticography is the most suitable method. Parenchymal injuries of the distal pancreas should be treated by drainage of the lesser sac using sump or closed-suction drains. Severe injuries of the body and tail as well as ductal injuries may be managed by distal pancre-atectomy in a stable patient. Injuries of the head of the pancreas that do not involve the duct, adjacent vessels, ducts or organs may be managed by appropriate surgical drainage. Pancreaticoduodenal resection is indicated for:
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Colon Colonic injuries are usually caused by penetrating trauma and are associated with a mortality of about 10%. Management of colonic injuries involves primary closure of the colonic wound, defunctioning colostomy or exteriorization of the repair, but controversy exists over when to use each technique. It has been customary to teach that left-sided colonic injuries require exteriorization of some form and are inherently more dangerous than right-sided wounds; this is not necessarily the case. Several studies have shown that colostomy formation is associated with a higher complication rate than equivalent wounds treated by primary repair. Non-destructive lesions should be closed primarily, independent of their location. With the more destructive colonic injuries requiring resection, in the absence of shock, preexisting medical conditions, major associated injuries or peritonitis it would seem reasonable to perform primary anastomotic repair, the alternatives being a defunctioning stoma with either a mucous fistula or a Hartmann’s procedure. For injuries to the right colon, a hemicolectomy and ileotransverse anastomosis provide good results. Exteriorization of a colonic repair appears to have few advocates. Spleen The spleen is the most common solid organ to be injured in blunt trauma. Given its important immunological and reticulo188
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endothelial functions, attempts should be made to salvage and preserve the spleen in children, adolescents and young adults, especially if the damage is minor. The spleen is inspected following mobilization and temporary haemostasis obtained by occluding the splenic pedicle. In small, inexperienced centres where help is not always at hand, exploration of all splenic injuries may be the safest course of action. Superficial capsular and parenchymal lacerations may be controlled by pressure, packing, electrocautery or suture. Deeper lacerations may be treated by partial splenectomy. If parenchymal injury is more severe or haemorrhage is a problem and if there is haemodynamic instability or associated major injury, splenectomy is advised. Patients should be treated with antibiotics during convalescence and given polyvalent pneumococcal vaccine before discharge to help prevent overwhelming post-splenectomy sepsis. Splenorrhaphy is possible in about 50% of patients undergoing laparotomy for splenic trauma and splenic re-implantation may be possible following control of immediate haemorrhage. Non-operative management for splenic trauma should be pursued only if there is: • absolute haemodynamic stability • minimal abdominal physical signs • negative diagnostic peritoneal lavage • blood transfusion requirement of <2 units. Stable patients with perisplenic haematoma should be managed conservatively, with clinical and radiological follow-up (i.e. vital parameters, abdominal findings, transfusion requirements coupled with repeated ultrasound/CT investigation.
often helpful. Early operative intervention is necessary for nonfunctioning kidneys before renal vein thrombosis supervenes or for profuse haemorrhage. Renal salvage is possible following most blunt and penetrating injuries. Injuries to the renal pedicle carry the greatest morbidity. Renal and ureteral injuries should be drained following repair. Vascular The principal feature of major vascular injury in the abdomen is haemorrhage and hypotension. Major haemorrhage is also the main cause of immediate death following blunt and penetrating injury. The principles of management are the same as for elective vascular surgery in that proximal and distal control of the vessel is required on either side of the injury. The aorta may be controlled initially by a transthoracic approach to the descending thoracic aorta or by encircling the abdominal aorta as it passes through the hiatus. Vena caval injury should be controlled by direct pressure because mobilization can tear lumbar veins. With haemorrhage under control, damage can be inspected. Major vessels should be explored by reflecting the viscera rather than dissecting into haematomas. Injured arteries should be debrided to remove damaged intima and repaired by primary suture, venous patch, venous onlay graft or the use of autogenous artery. Synthetic prosthesis should be avoided if the peritoneum has been contaminated. Penetrating injuries of the infrarenal vena cava should be treated by repair of both the posterior and anterior wall, the former being accomplished by suture inside the vessel. Retrohepatic vena caval injuries are difficult to treat and are usually fatal.
Liver The liver is the most common organ injured following penetrating trauma. Injuries range from simple capsular avulsion or tear, which requires little operative management, to retrohepatic vena cava injury associated with bilobar parenchymal disruption, which is often rapidly fatal. There is a shift towards non-operative management of isolated liver injuries. The basic principles in the management of hepatic trauma are control of haemorrhage, removal of devitalized tissue and perihepatic drainage. The basic techniques useful in operative management include: • in-flow occlusion • suture • packing with closure and planned re-exploration • hepatic artery ligation • resection • mesh hepatorrhaphy • atrial-caval shunting (a shunt placed between the infrahepatic vena cava and the right atrium that allows exclusion, visualization and subsequent repair of major hepatic vein injuries). The anatomy of the liver and the distribution and pattern of injuries permit separation of the role of each of these approaches. Mortality from hepatic injuries is about 10% and the most common cause of death is shock and transfusion coagulopathy in the perioperative period. Sepsis is the most common complication.
Pelvis Fractures: haemorrhage from a pelvic fracture may be sufficient to defeat resuscitation until the pelvis has been stabilized by external fixation. Angiography and embolization may be indicated if haemodynamic instability persists despite resuscitation and pelvic fixation. Pelvic fractures are associated with high mortality and morbidity rates. Urinary bladder: intraperitoneal rupture of the bladder must be repaired in two layers and suprapubic or urethral drainage maintained postoperatively. Extraperitoneal rupture may be treated effectively with bladder drainage alone. Perineal injuries: the basic principles of surgical treatment are: • urinary diversion by a suprapubic cystostomy for urogenital lesions • faecal diversion by terminal colostomy for rectal/ano-sphincteric lesions • debridement and drainage of contaminated soft tissue and connective tissue spaces • conservative debridement of the margins of the anal or urethral wounds. u
Renal Haematuria should be investigated with intravenous pyelogram to exclude renal trauma or bladder rupture. If either kidney is not visualized, emergency angiography should be carried out to assess the renal vessels and their function; contrast CT is
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FURTHER READING Navsaria P H, Bunting M, Omoshoro-Jones J, Nicol A J, Kahn D. Temporary closure of open abdominal wounds by the modified sandwichvacuum pack technique. Br J Surg 2003; 90(6): 718–22.
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