Non-traumatic spontaneous abdominal haemorrhage

Abstract

Spontaneous abdominal hemorrhage is defined as intra-abdominal hemorrhage from a non-traumatic cause. It is a challenging clinical situation and in most cases the diagnosis is made on the basis of imaging findings. CT is the technique of choice for the detection, localization and extension of bleeding.

Objective is to review the main imaging findings expected in spontaneous abdominal hemorrhage as well as its main etiologies.

Resumen

La hemorragia abdominal espontánea es aquella de causa no traumática que supone una situación clínica desafiante y un diagnóstico que, en la mayoría de los casos, será radiológico. La tomografía computarizada (TC) es la técnica de elección para la detección, la localización y la extensión del sangrado.

El objetivo de este trabajo es repasar los principales hallazgos de imagen esperados en la hemorragia abdominal espontánea en las distintas pruebas radiológicas y sus principales causas.

Introduction

Spontaneous abdominal haemorrhage is a situation that requires early diagnosis; symptoms are non-specific, but it can lead to hypovolaemia and shock.¹ There are multiple potential causes of abdominal haemorrhage and it can occur in different locations. Depending on the organ affected, abdominal bleeding can be classified as visceral (hepatic, splenic, renal, adrenal and gastrointestinal), gynaecological, vascular or coagulopathy-related.

Non-gastrointestinal abdominal haemorrhage can present with severe pain and abdominal distension. Laboratory values may not initially reflect the extent of blood loss and, if not promptly treated, the morbidity and mortality rates can be high. In the case of bleeding from the gastrointestinal tract, the symptoms are usually less pronounced, with the patient's clinical status and laboratory test results guiding the diagnosis on arrival in Accident and Emergency.

Role of radiology in abdominal haemorrhage

Radiologists play an increasingly important role in the diagnosis and treatment of abdominal haemorrhage. Nowadays, we have a number imaging techniques capable of identifying the source of bleeding,^1,2 including ultrasound, computed tomography (CT) with intravenous contrast (IVC) and more recently, dual-energy CT.

Ultrasound: initial imaging technique, especially in unstable patients or when abdominal bleeding of gynaecological origin is suspected.^1,2 Haemoperitoneum has a non-specific appearance on ultrasound and can be hypo-, iso- or hyperechogenic. It can also appear as heterogeneous collections or with a fluid-fluid level. If haemoperitoneum is hypoechoic, it may be indistinguishable from ascites. The presence of clots (grouped echogenic content) in the vicinity of an organ helps locate the source of bleeding.

However, the ultrasound scan has a limited role, as it cannot detect active bleeding or provide an adequate acoustic window to assess the deep peritoneal and retroperitoneal spaces.

CT: technique of choice; CT has high sensitivity and specificity for locating the haemorrhage, it helps identify whether the origin is arterial or venous and it enables non-invasive assessment of the vascular tree and a complete study of the patient.^1–3 The technical protocol consists of three equal phases extending from the domes of the diaphragm to the pubic rami; in case of uncertainty and at the discretion of the radiologist, an optional late phase can be added:

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  Non-IVC phase: enables identification of hyperdense material (blood, sutures, clips, calcifications) and prevents confusion with the extravasated contrast, which can be seen in the IVC phase.

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  Arterial phase: 100−150 ml of IVC, depending on the weight of the patient, are administered at a rate of 4 ml/s; image acquisition according to the bolus-tracking technique with the region of interest in the descending aorta and with a threshold of 150 Hounsfield units (HU).

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  Portal venous phase: 70 s after the contrast injection, we can determine whether or not the bleeding is active. Identification of highly attenuated foci in the arterial phase that increase in the venous phase means there is active bleeding, which may be indicative of the need for urgent embolisation or other urgent, surgical or endocavitary treatments,^1,2 or a watch and wait approach in low-output bleeds. This phase also makes it possible to identify any underlying lesion as the cause of bleeding.

Dual-energy CT: this is an essential technique in routine practice in emergency radiology and one of its applications is the detection of abdominal bleeding, offering certain advantages: it makes it possible to dispense with baseline acquisition without contrast thanks to virtual non-contrast reconstruction mapping, thus reducing scanning and radiation time; and it accurately assesses contrast extravasation and iodine quantification, enabling the dose of IVC to be reduced.

Appearance of haemorrhage on CT

The distribution of the haemorrhage depends on the severity of the bleeding, the organ or mass of origin and the abdominal compartment, and it may spread freely through the peritoneum or retroperitoneum.³ The appearance varies depending on the quantity, the stage of the bleeding and the haematological parameters.¹ In images without IVC, hyperacute bleeding has an attenuation of 30–45 HU due to the high protein content. After a few hours, the now clotted blood, as the haemoglobin concentration increases, reaches an attenuation of over 60–70 HU (this then decreases with time). Clots are geographical areas of high attenuation, are usually surrounded by areas of lower density or serum,¹ and may form a fluid-fluid level (low-density serum in the upper region and hyperdense blood in the lower region). Clots tend to form near the bleeding site, so identification of a relatively higher attenuation clot than the rest of the intra-abdominal fluid enables localisation of the site of haemorrhage (sentinel clot sign).^1,2 The amount of blood also helps us identify the site of an active haemorrhage, as the largest amount is usually close to the source.

Causes of abdominal haemorrhage

Visceral causes

Hepatobiliary

Spontaneous hepatic haemorrhage is rare, usually secondary to tumour rupture, connective tissue diseases (amyloid, lupus), polyarteritis nodosa, and HELLP syndrome (haemolytic anaemia, elevated liver enzymes and thrombocytopenia). The pathogenesis of the bleeding is not fully understood, but it is probably a multifactorial process involving a compromise of vascular integrity. In the case of tumours, spontaneous haemorrhage can occur both in large central lesions and in small superficial lesions. In addition, necrosis and tumour growth would lead to an increase in tissue pressure, encouraging development of venous thrombi and compromising tumour neovascularisation, creating the conditions for rupture of the liver capsule.^4,5

The types of tumour most frequently associated with spontaneous bleeding are hepatocellular carcinoma and adenoma.^3–5 Hepatocellular carcinoma is the most common type of primary liver cancer. Although it can develop in healthy livers, hepatocellular carcinoma is more common in patients with liver cirrhosis of any aetiology (Fig. 1).⁶ The risk factors most associated with bleeding are as follows:

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  Young patients.

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  Hepatitis B infection.

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  Large tumours (over 5 cm in size).

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  Invasive tumours.

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  Exophytic/pedunculated tumours or tumours located in subcapsular regions.

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  High Child-Pugh score.

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  Thrombocytopenia.

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  Previous treatment with transarterial chemoembolisation.

Figure 1.

Bleeding and rupture of a hepatocellular carcinoma. CT of abdomen in the phase without intravenous contrast (A), in the arterial phase after administration of intravenous contrast (B) and in the venous phase (C). We can see a hypervascular intrahepatic lesion located in segment four (white arrow), with hypodensity due to lavage in the venous phase (red arrow). In axial, sagittal (D) and coronal (E) slices, the break in continuity is evident at the hepatic border of the lesion, with associated acute haemorrhage and haemoperitoneum (asterisk). The angiographic study (F) showed tumour vascularisation dependent mainly on the left hepatic artery and, to a lesser extent, on the right hepatic artery. It was treated with particle embolisation (300–500 μs).

The tumour with the second highest risk of bleeding is adenoma, particularly the inflammatory subtype, with a bleeding risk of 30%.³ Liver adenomas can develop in young women who take oral contraceptives, although it also occurs in men treated with anabolic steroids, in patients with diabetes and in people with iron deposit disorders. They are usually single lesions, large at the time of diagnosis, and their location is almost always subcapsular; most bleeding is intratumoural. Other lesions with a lower risk of bleeding are hypervascular liver metastases (such as lung or melanoma), haemangioma, simple cysts and liver angiosarcoma.

Rupture of a superficial tumour will usually occur into the peritoneal cavity and imaging will show focal discontinuity of the capsule adjacent to the tumour, subcapsular haematomas, haemoperitoneum and active peritumour bleeding.⁴

Pancreatic

Spontaneous haemorrhages in the pancreas are rare and life-threatening. They are usually secondary to complications of acute pancreatitis, due to rupture of either pseudoaneurysms or pseudocysts.^4,7 The haemorrhage is due to diffusion of proteolytic enzymes. CT images will show blood collections in the gland itself or in the peripancreatic spaces with or without active bleeding.⁴ Spontaneous haemorrhage from pancreatic cancer is a very rare complication.³

Gastrointestinal

Acute intestinal haemorrhage is an urgent condition with a high mortality rate, which can reach 40% in massive bleeding, and even higher values in older adult patients with comorbidities.

They can be classified as upper or lower based on their location, according to whether they originate proximal or distal to the angle of Treitz. It is an upper gastrointestinal haemorrhage in 75% of cases and the signs are haematemesis or melaena. The most common cause is peptic ulcer disease and, in patients with portal hypertension, oesophageal varices. Lower gastrointestinal bleeding originates between the angle of Treitz and the rectum; it accounts for approximately 25% of cases and clinically presents as rectal bleeding, haematochezia or melaena, and the main cause is diverticular disease. Other causes are vascular lesions (angiodysplasia of the colon), cancer, inflammatory colitis, infections and benign anorectal lesions (Figs. 2 and 3).⁸

Figure 2.

Patient with rectal bleeding. Active diverticular bleeding. CT of abdomen in the phase without intravenous contrast (A), in arterial phase (B) and in venous phase (C) after administration of intravenous contrast. The study without intravenous contrast shows no findings, while in the arterial phase contrast extravasation is identified within the lumen of the sigmoid colon (white arrow), adjacent to the multiple diverticula, which is even more accentuated during the venous phase (red arrow).

Figure 3.

A) The abdominal CT scan shows discontinuity of the calcifications in the aneurysm wall (red arrow). B) CT of abdomen in arterial phase with periaortic haematoma, which shows as a focal area of soft tissue density intimately attached to the aneurysm wall (blue arrow). C) CT of abdomen in phase without intravenous contrast. Abdominal aortic aneurysm, with crescent-shaped hyperdensity, indicating haematoma in the aneurysm wall (white arrow). D) CT of abdomen in arterial phase. Rupture of the left posterior-lateral wall, with retroperitoneal haematoma and active contrast leak (asterisk). E and F) Mesenteric bleeding in a patient with a history of liver transplantation who had a drop in haemoglobin. CT of abdomen in arterial phase (E) and venous phase (F) after administration of intravenous contrast. Significant arterial bleeding can be seen in the transverse mesocolon (white arrow), which increases significantly in the venous phase (yellow arrow). There is also haemoperitoneum and perihepatic haematoma.

The imaging technique of choice for the study of upper gastrointestinal bleeding is endoscopy. In CT scans, the key to diagnosis is to identify the extravasation or jet of the IVC within the intestinal lumen (direct sign of bleeding). Scans should be performed at the point when we most suspect active and continuous bleeding, as this notably increases the sensitivity of the technique. Positive oral contrast should not be administered, as iodine is hyperdense and hinders detection of extravasation in the intestinal lumen (it can even hide it). Neutral agents such as water should also not be administered, as they may dilute subtle bleeding.⁹

Indirect signs of bleeding are thickening of the loop wall and blood collections adjacent to the loop. We should not confuse contrast extravasation with normal mucosal enhancement and beam-hardening artefacts. On CT, false negatives include patients with intermittent bleeding and low-flow bleeding.

Renal

Spontaneous renal haemorrhage: also known as Wünderlich syndrome. Although multiple aetiologies have been described that can trigger the condition, the most common cause is angiomyolipoma.^3,9,10 Spontaneous bleeding originating from a renal mass containing fat content is virtually pathognomonic of angiomyolipoma. Although rare, it is extremely important to be aware of this condition, as it can become complicated and cause bleeding into the subcapsular and perirenal space, and has the potential to be life-threatening.

Secondary renal haemorrhage: the most common causes of non-tumour-related aetiology are anticoagulant therapy, blood dyscrasias, myeloma (Fig. 4), vasculitis (the most common being polyarteritis nodosa), renal cysts and renal lithiasis treated with lithotripsy.

Figure 4.

A–D) Right adrenal spontaneous bleeding. CT of abdomen in the phase without intravenous contrast (A), in arterial phase (B) and in venous phase (C and D) after administration of intravenous contrast. Contrast extravasation can be seen in the arterial phase, which increases in the venous phase, in the right adrenal space, with extension to the perirenal space, corresponding to active arterial bleeding (white arrows). The right kidney is displaced by the haematoma with intact parenchyma (red arrow in image D in the sagittal plane). E–G). Left renal haemorrhage. 59-year-old woman with adult respiratory distress syndrome with sudden deterioration and acute abdomen. CT of abdomen in arterial phase (E) and venous phase (F). Destructuring of the left kidney can be seen with large retroperitoneal and perirenal haematoma (yellow arrows). Selective angiography (G) shows destructured renal parenchyma with little viability, so it was decided to perform complete renal artery embolisation with spongostan and proximally with two coils of 6 and 4 mm.

Treatment options vary, depending on the patient's clinical condition and haemodynamic status, and include a conservative approach, partial or radical nephrectomy and tumour resection. Selective renal angiography for embolisation of the bleeding vessel (Fig. 4) is a highly useful technique, as it can help confirm the diagnosis, identify the exact area of haemorrhage and control the bleeding, thus avoiding emergency surgery.

Adrenal

Spontaneous adrenal haemorrhages are uncommon and may be caused by situations of stress (burns, hypovolaemia), coagulation disorders, antiphospholipid syndrome, anticoagulant drugs, adrenal gland tumours, complicated surgery or sepsis (meningococcal septicaemia is fulminant, causing Waterhouse-Friderichsen syndrome),² or be idiopathic (Fig. 3).

Benign or malignant adrenal tumours are the fourth leading cause of spontaneous unilateral retroperitoneal haematoma. Pheochromocytoma is the most common cause of massive haemorrhage; primary carcinomas and metastases, usually from lung cancer, can also cause haemorrhage. Cysts and myelolipomas may bleed into the parenchyma or rupture into the surrounding space; adrenal haemangiomas are very rare, but they bleed easily.^6,11

Splenic

Non-traumatic splenic haemorrhage is rare, but potentially fatal if not properly treated. It is usually related to a diseased spleen, mainly in association with infectious causes, such as viruses, with Epstein-Barr virus infectious mononucleosis being the most common cause of rupture (only occurs in 0.5%–1.5% of patients with mononucleosis); haematological disorders (lymphoma, leukaemia, polycythaemia); metastases (lung, breast, melanoma, ovary); or inflammatory disease.^12,13 The aetiopathogenic mechanism of rupture of the spleen is still not fully understood, but multiple factors are thought to be involved, such as increased intrasplenic pressure or vascular occlusion, with findings of splenomegaly and blood content, both perisplenic and inside the spleen, on CT.

It is estimated that the spleen has normal histological characteristics in less than 7% of spontaneous ruptures of the spleen. There is confusion regarding the terms 'pathological rupture' and 'spontaneous rupture', which have been used interchangeably, despite being two very different conditions. Pathological rupture is used when there is associated disease, whether splenic or not. In contrast, we refer to spontaneous rupture if the following Orloff and Peskin criteria are met¹⁴:

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  Absence of trauma or stress that might explain the rupture of the spleen.

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  Absence of a systemic or local disease that might affect the spleen and cause it to rupture.

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  Absence of perisplenic adhesions or scars suggestive of possible previous trauma.

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  Macroscopic and histological study of a strictly normal spleen.

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  There should not be high titres of viral antibodies capable of affecting the spleen.

Many authors¹⁴ believe that there is no such thing as spontaneous rupture and that there is always some trigger that simply cannot be identified. A multitude of viral agents that may be able to trigger rupture have recently been reported, having previously gone unrecognised. However, despite advances in diagnosis and medical knowledge, cases of spontaneous rupture continue to be reported.

Knowing whether the spleen is diseased or not helps us to treat the underlying disease.

Gynaecological

The causes of gynaecological bleeding can be tumour-related or non-tumour-related.

In women of reproductive potential, the most common cause of spontaneous haemoperitoneum is the rupture of a haemorrhagic ovarian cyst.^1,4 This usually presents with acute pelvic pain. Ultrasound findings vary depending on the time elapsed since the bleeding. At its most acute, it may be hyperechogenic and simulate a solid mass, although with posterior acoustic reinforcement due to its cystic component. In the subacute phase, it behaves like a complex cystic lesion, with a fine reticular pattern inside due to fibrin bands, which gives it a typical fishnet appearance. It sometimes presents with a fluid-fluid level, with internal echoes. The internal clot may simulate an ovarian nodule or mass, hyperechogenic but with no flow on colour Doppler imaging.¹⁵

Another cause of acute abdominal pain and haemoperitoneum in women of childbearing potential is the rupture of an ectopic pregnancy. Both the rupture of an ovarian cyst and that of an ectopic pregnancy have similar symptoms and ultrasound signs. The key parameter that differentiates the two is serum human chorionic gonadotropin; above 2000 IU in ectopic pregnancy.

CT can confirm the existence of adnexal blood content and free fluid in the pelvis. An adnexal ring image can be seen on ultrasound, while contrast-enhanced CT shows ring enhancement, which suggest a diagnosis of complicated ectopic pregnancy.² Rarely, rupture of an ovarian endometrioma may occur, which clinically mimics the rupture of a functional ovarian cyst.⁴

The most common causes among gynaecological tumours are endometrial carcinoma, followed by ovarian carcinoma and cervical carcinoma.

Bleeding is rare in this type of disease, but aggressive cancers can cause invasion of surrounding organs and erosion of blood vessels, which can lead to intraperitoneal and pelvic haemorrhage, associated with haematuria and gastrointestinal bleeding.

Vascular

Abdominal bleeding from vascular causes may be due to rupture of an aneurysm, pseudoaneurysm, dissection of an artery or erosion of a vessel by tumours, inflammatory processes, vasculitis or cysts.

The most common cause of vascular bleeding is the rupture of an abdominal aortic aneurysm (AAA), followed by iliac, splenic and hepatic aneurysms.¹⁶ Rupture of aneurysms of the coeliac and gastroduodenal arteries is less common.^17,18 A patient with a ruptured AAA exhibits symptoms of abdominal pain and hypovolaemic shock.

CT angiography of the abdominal aorta is the imaging modality of choice for diagnosis (Fig. 3).

AAA rupture has catastrophic consequences with a high mortality rate; 50% of patients die before reaching hospital and up to 40% after surgery. It is therefore very important to recognise the imaging signs of impending rupture of the wall of an aneurysm¹⁹:

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  Rapid increase in the size of the aneurysm: from 4 cm in diameter it tends to increase by 3 mm per year. For every 5-mm increase, there is a growth rate of 0.5 mm per year and the risk of rupture doubles.

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  Intramural haematoma appearing as a crescent-shaped hyperattenuating area in the aneurysm wall on scan without IVC.

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  Focal wall discontinuity: a change in the intimal calcifications may indicate the site of rupture. This sign is useful if there are previous studies with which to compare it. Alternatively, focal bulging of the aneurysm wall may be seen, corresponding to inflammatory changes and focal thinning of the wall.

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  “Crescent sign”, observed when blood is dissecting the mural thrombus in the aneurysm wall.

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  The “draped aorta sign” consists of loss of definition of the posterior wall of the aneurysm, anterior to the surface of the adjacent vertebral body, with loss of the fat plane between the aneurysm and the vertebral body, and is a sign of contained rupture.

The findings of complete or established rupture of the aneurysm are loss of continuity of the aortic wall and presence of a retroperitoneal haematoma adjacent to the aneurysm sac. Bleeding can extend to the intraperitoneal compartment if the rupture occurs on the anterior wall of the aortic aneurysm. If contrast extravasation is detected, it is an unequivocal sign of aneurysm rupture.^1,19

AAA rupture is a surgical emergency that cannot be delayed. Treatment of the aneurysm can be delayed from 4 to 24 h in haemodynamically stable patients with AAA but showing no signs of complete rupture, as it improves the preoperative conditions. Otherwise, it must be treated immediately. The standard treatment is open surgical repair.

Bleeding related to coagulopathy

In patients taking anticoagulants or antiplatelet agents, spontaneous coagulopathy-related retroperitoneal bleeding can occur.¹

The symptoms are mostly non-specific. This is more common in older adult patients, in whom severe acute bleeding can cause hypovolaemic shock. The most common location of such bleeding is the iliopsoas muscle, coming from a lumbar artery and the anterior rectus muscle of the abdominal wall, coming from the epigastric artery.

The medical history usually points to the diagnosis. However, an underlying mass should be sought in patients with known cancer, so follow-up is necessary to monitor how the haematoma resolves.

Another potential outcome of a coagulopathy-related bleed is a rectus sheath haematoma, which can extend extraperitoneally towards the pelvis, below the linea alba, and be confused with pelvic masses.

Spontaneous mesenteric haematoma

Spontaneous mesenteric haematoma is intra-abdominal bleeding without previous trauma or iatrogenic history and can be confused with lymph nodes or tumour masses, so it is important to monitor how it evolves (Fig. 3). Mesenteric bleeding can be caused by anticoagulant therapy, rupture of visceral aneurysms, connective tissue diseases, acute pancreatitis or cancer-related as a result of sarcoma, neurogenic tumours, germ cell tumours, metastases and even lymphoma.⁸ The cause is not found in up to 40% of cases.

Conclusion

Spontaneous intra-abdominal haemorrhage is a diagnostic challenge, as a high index of suspicion is required to point us to the pertinent tests and guide the appropriate treatment. We must be alert to the wide variety of conditions that can cause spontaneous abdominal bleeding. CT determines the site and extent of bleeding, and in most cases identifies the underlying disease process.

Authorship

• 1

  Responsible for the integrity of the study: PEL

• 2

  Study conception: PEL

• 3

  Study design: PEL

• 4

  Data collection: PEL, MBM, SBF and RMPO

• 5

  Analysis and interpretation of the data: PEL, MBM, SBF and RMPO

• 6

  Statistical processing: N/A

• 7

  Literature search: PEL, MBM, SBF and RMPO

• 8

  Drafting of the article: PEL, MBM, SBF and RMPO

• 9

  Critical review of the manuscript: PEL, MBM, SBF and RMPO

• 10

  Approval of the final version: PEL, MBM, SBF and RMPO

Conflicts of interest

The authors declare that they have no conflicts of interest.