Acute abdomen in pregnancy: role of sonography

Acute Abdomen in Pregnancy: A Comprehensive Review of Diagnosis and Management

An unusual diagnostic and treatment challenge is presented by an acute abdomen during pregnancy. Obstetric factors and other causes unrelated to pregnancy also contribute to acute abdominal discomfort in pregnancy. Due to the changing clinical presentations brought on by the anatomical and physiological changes of pregnancy as well as the hesitation to utilize certain radiological studies out of concern about damaging the fetus, the diagnosis of the acute abdomen during pregnancy can be challenging. Delays in identification and treatment may have negative effects on the mother as well as the fetus. This review sheds light on the importance of anatomical and physiological considerations, early diagnoses, and understanding the various modalities and etiologies of acute abdomen in pregnancy (AAP). We then move on to discuss the various diagnostic techniques that can help the physician determine the causes and plan well-informed treatment. We examine and contrast different radiographic tests, including X-rays, computed tomography, magnetic resonance imaging, and ultrasound. We also talk about the various roles that these investigational methods can play in the evaluation and treatment throughout the duration of the pregnancy. The paper additionally addresses how to handle patients who appear with AAP and the different techniques used to treat them, including pre-operative laparoscopy. Before going over some more broad points that might be useful, we eventually dive into some of the more intriguing etiologies relating to AAP, such as isolated tubal torsion and neoplastic complications.

Case report: Emergency presentation of Meckel's diverticulum in the 3rd trimester of pregnancy

Background

Symptomatic Meckel's diverticulum (MD) is easily neglected in the acute abdomen during pregnancy. MD is the most common congenitally anomalous development of the intestines, with an incidence of 2% in the general population, although it is not easily diagnosed because of variable clinical features. Especially when complicated with pregnancy, doctors can easily overlook this disease, which directly threatens maternal and foetal life.

Case Presentation

We report the case of a 25-year-old at 32 + 2 weeks of gestation complicated with MD volvulus who presented with progressive abdominal pain and finally peritonitis. She underwent exploratory laparotomy and small-bowel resection. The mother and the baby successfully recovered.

Conclusions

MD-complicated pregnancy is not easily diagnosed. Once highly suspiciously diagnosed, especially with peritonitis, surgery should be arranged, which helps preserve maternal and foetal life.

Systematic review of Meckel's diverticulum in pregnancy

INTRODUCTION

Meckel's diverticulum (MD) is the most common congenital malformation in the gastrointestinal tract. Limited up-to-date evidence is available regarding MD in pregnancy. We aim to review the available pertinent literature to help support clinical decision making and patient management in the future.

MATERIALS AND METHODS

The search term 'Meckel's diverticulum' was combined with 'pregnant' or 'pregnancy'. Database searches of EMBASE, Medline and PubMed were conducted. All papers published in English from 01/01/1990 to 01/01/2021 were included. Simple statistical analysis (t-test) was performed.

RESULTS

Twenty-seven cases were included. Average age = 26.9 years. Average gestation = 25.1 weeks. Occurrence: first trimester = 3.7%; second trimester = 48.1% and third trimester = 48.1%. Presenting symptoms: abdominal pain 88.9%; nausea/vomiting 59.3%; fever 18.5%; abdominal distension 18.5%; haematochezia 11.1%; constipation 11.1%; haematemesis 3.7%, diarrhoea 3.7% and asymptomatic 3.7%. Mean duration of preceding symptoms = 3.4 days. Diagnostic imaging modalities utilised: ultrasound = 40.7%; CT = 25.9%; MRI = 14.8%; abdominal X-ray = 11.1% and endoscopy = 7.4%. All cases required definite surgical management: laparotomy = 65.4%; laparoscopy = 15.4%; C-section = 19.2% and unreported = 3.8%. Main intra-operative findings: perforated MD = 40.7%; intussusception with MD as a lead point = 11.1%; bleeding MD = 11.1%, inflamed MD = 11.1%; small bowel obstruction = 11.1%; gangrenous MD = 3.7%; volvulus = 3.7% and unspecified = 7.4%. Mean length from ileocolic junction = 51.7 cm. Average length of stay was 7.1 days. T-test (p-value = 0.12) when comparing management strategy. Three maternal complications and two foetal mortalities.

CONCLUSION

MD and associated pathology are difficult to diagnose in the pregnant cohort. Current imaging demonstrates low diagnostic accuracy and a deviation away from recognised nuclear medicine investigations. Surgery appears the definitive management with both open and laparoscopic approaches utilised. Significant maternal morbidity and foetal mortality are associated with this condition.

MRI in pregnancy: Indications and practical considerations

There is a constantly evolving knowledgebase regarding the safety of MRI in pregnant patients, as well as the safety of gadolinium administration, given potential fetal risks. This review provides an overview of national and international recommendations for patient screening and safety by trimester, evaluates the most recent literature regarding administration of gadolinium in pregnant patients, and discusses technical requirements when imaging pregnant patients. A protocol for imaging pregnant patients is provided, and multiple common indications for MRI in pregnancy are discussed. Level of Evidence 5. Technical Efficacy Stage 5. J. Magn. Reson. Imaging 2019;49:621-631.

Suspicion of appendicitis in pregnant women: emergency evaluation by sonography and low-dose CT with oral contrast

OBJECTIVES

To evaluate non-intravenously enhanced low-dose computed tomography with oral contrast (LDCT) for the assessment of pregnant women with right lower quadrant pain, when magnetic resonance imaging (MRI) is not immediately available.

METHODS

One hundred and thirty-eight consecutive pregnant women with acute abdominal pain were admitted in our emergency centre. Thirty-seven (27%) of them, with clinical suspicion of acute appendicitis, underwent abdominal ultrasonography (US). No further examination was recommended when US was positive for appendicitis, negative with low clinical suspicion or showed an alternative diagnosis which explained the clinical presentation. All other patients underwent LDCT (<2.5 mSv). Standard intravenously enhanced CT or MRI was performed when LDCT was indeterminate.

RESULTS

Eight (22%) of 37 US exams were reported normal, 25 (67%) indeterminate, 1 (3%) positive for appendicitis, 3 (8%) positive for an alternative diagnosis. LDCT was obtained in 29 (78%) patients. It was reported positive for appendicitis in 9 (31%), for alternative diagnosis in 2 (7%), normal in 13 (45%) and indeterminate in 5 (17%). Further imaging (standard CT or MRI) showed appendicitis in 2 of these 5 patients, was truly negative in 1, indeterminate in 1 and falsely positive in 1. An appendicitis was confirmed at surgery in 12 (32%) of the 37 patients. The sensitivity and the specificity of the algorithm for appendicitis were 100% (12/12) and 92% (23/25), respectively.

CONCLUSIONS

The proposed algorithm is very sensitive and specific for detection of acute appendicitis in pregnant women; it reduces the need of standard CTs when MRI is not available as second-line imaging.

KEY POINTS

• In pregnant women, US is limited by an important number of indeterminate results • Low-dose CT can be used after an inconclusive US for the diagnosis of appendicitis in pregnant women • An algorithm integrating US and low-dose CT is highly sensitive and specific for appendicitis in pregnant women.

The Diagnosis of Obstructive Hydronephrosis with Color Doppler Ultrasound

Background:

The obstructive hydronephrosis is a term that implicates the structural and functional changes of the kidneys as a result of difficulties in the flow of urine. Hydronephrosis specifically describes dilation and swelling of the kidney. Hydronephrosis is a condition that typically occurs when the kidney swells due to the failure of normal drainage of urine from the kidney to the bladder. Our aim was to evaluate the degree of hydronephrosis, causes and diagnostic method. Material and

Methods:

This is a study of 136 patients that have been treated at the Department of Urology, University Clinical Centre of Kosovo, Prishtina. For diagnosis of hydronephrosis in our patient, we used as equipment the Color Doppler ultrasound, with resolution of 3.5 MHz–8 MHz.

Results:

Out of 136 participants in the study, 91 (66.9%) were males and 45 (33.1%) females, with significant difference (P=0.000). The average age for males was 49 years old, whereas for females was 33. This study included patients with a diagnosis of symptomatic hydronephrosis with various causes and degrees. All patients were presented with hydronephrosis. The hydronephrosis grade varied from the stage I up to the IV. In our study we have difference grade of hydronephrosis, X² test, P= 0.114. The most common causes of hydronephrosis in our study were; kidney stone, ureteral stones, neck stenosis PU, pregnancy, infiltrating bladder cancer, bladder neck contracture, prostate adenoma, infiltrating prostatic carcinoma etc. In this study we have indentified different causes, of which stones dominate as the most usual causes of hydronephrosis P= 0.0001.

Conclusion:

The Ultrasound is an easy method to be applied, non invasive, and a fast one to help and diagnose the obstructive hydronephrosis. The ultrasound has a high sensitivity and should be used as a screening method followed by other methods, as necessary. Hydronphrosis is most commonly presented to men with an average age about fifties. We came to the conclusion that the main causes of hydronephrosis are kidney stone, followed by ureteral stones, in which, in a larger percentage, they appear with the II degree of hydronephrosis.

Evolving Practice Patterns in Imaging Pregnant Patients With Acute Abdominal and Pelvic Conditions

OBJECTIVE

The purpose of our study was to determine the current practice patterns of U.S. radiologists in imaging pregnant or potentially pregnant patients with acute abdominal and pelvic conditions.

MATERIALS AND METHODS

After obtaining an Institutional Review Board waiver, all members of the Association of University Radiologists, the Association of Program Directors in Radiology, and the Society of Radiologists in Ultrasound were invited via e-mail to take a 23-question online survey on radiology practices and clinical scenarios about acute abdominal and pelvic imaging of pregnant patients.

RESULTS

Comparisons were made with previously published surveys. A total of 225 responses were received. Areas of high consensus included pregnancy assessment (97%) and obtaining informed consent (87%) before imaging, having a written policy on imaging pregnant patients (79%), modification of computed tomography (CT) protocols (74%), avoiding gadolinium contrast in magnetic resonance imaging (MRI) (74%), using ultrasound for initial imaging in some scenarios, and using CT in trauma cases after inconclusive ultrasound. Areas of emerging consensus compared to 2007 included the use of serum or urine testing to confirm pregnancy status (59.4%; previously 14%) and the use of MRI in suspected appendicitis after an inconclusive ultrasound (73% in first trimester and 67% in third trimester; previously 46% and 29%, respectively). Areas without clear consensus included policy development, additional modifications to MRI protocols, choice of imaging modality, radiation dose, and the use of contrast agents in some scenarios.

CONCLUSION

In conclusion, high or increasing consensus exists in some areas of imaging pregnant patients with acute abdominal and pelvic conditions, but has yet to emerge in other areas.

Meckel's diverticular perforation presenting as acute abdomen in the second trimester of pregnancy

Meckel's diverticular perforation is a rare cause of acute abdomen during pregnancy. We report the case of a 24-year-old woman at 24 weeks of gestation who presented with abdominal pain for 4 days accompanied with abdominal distension, tenderness and guarding in right lower quadrant. Ultrasonography was inconclusive. The patient underwent exploratory laparotomy with the clinical suspicion of appendicular perforation peritonitis. Intraoperatively, a perforated Meckel's diverticulum was detected. Owing to gross contamination of the peritoneal cavity, a diverticulectomy with ileostomy was performed. She had a normal full-term vaginal delivery, and ileostomy was reversed 1 month after delivery. The physiological and anatomical changes in pregnancy can make a straightforward clinical diagnosis difficult. A high index of suspicion is required to prevent delay in diagnosis and surgical intervention, which could prove detrimental to the mother and fetus.

Errors in imaging the pregnant patient with acute abdomen

Pregnant women with an acute abdomen present a critical issue due to the necessity for an immediate diagnosis and treatment; in fact, a diagnostic delay could worsen the outcome for both the mother and the fetus. There is evidence that emergencies during pregnancy are subject to mismanagement; however, the percentage of errors in the diagnosis of emergencies in pregnancy has not been studied in depth. The purpose of this article is to review the most common imaging error emergencies. The topics covered are divided into gynecological and non-gynecological entities and, for each pathology, possible errors have been dealt with in the diagnostic pathway, the possible technical errors in the exam execution, and finally the possible errors in the interpretation of the images. These last two entities are often connected owing to a substandard examination, which can cause errors in the interpretation. Consequently, the systemization of errors reduces the possibility of reoccurrences in the future by providing a valid approach in helping to learn from these errors.

Rare causes of acute abdomen in pregnancy: “ultrasound to the rescue”. A review of two cases

Acute abdomen in pregnancy poses special challenge to the pregnant woman, her unborn infant, and the attending physician. The problems are multifactorial, as the physiological changes in pregnancy mask some of the clinical signs that can be elicited in making accurate diagnosis. Some diagnostic modalities are not feasible in pregnancy because of their effects on the fetus. Another dilemma is that two lives are at stake. It becomes even more challenging when one is faced with rare causes. For these reasons, the choice of diagnostic modality becomes critical. The chosen diagnostic modality should not only be readily available, non-invasive, least hazardous to the mother and fetus, but should also provide adequate information to enable accurate diagnosis. Ultrasonography provides such an opportunity and should be utilized whenever the need arises. We present two cases of acute abdomen in pregnancy managed at Abubakar Tafawa Balewa University Teaching Hospital: one was seen in the third trimester and the other in the first trimester, each with its peculiar presentation. The review is meant to alert obstetricians on the critical role of ultrasound in enhancing accurate diagnosis in the face of a complex clinical condition like acute abdomen in pregnancy.

[Protection of the unborn child in diagnostic and interventional radiological procedures]

The radiation exposure of an unborn child should be principally avoided, whenever it is medically reasonably possible; therefore, the identification of pregnant patients is the first and the most important step in radiation protection of the unborn child. However, in cases of emergency saving the life of the patient has a higher priority than the radiation protection of the unborn child. In this review article, we present a longitudinal section through the national and international literature and guidelines as a basis for radiological management of a (possibly) pregnant patient. We also list some radiological procedures recommended in the literature for a series of maternal indications considering the contraindications of each method during pregnancy and radiation protection of the unborn child.

Roux-en-Y gastric bypass-associated bowel obstruction complicating pregnancy-an obstetrician's map to the clinical minefield

Over 80% of patients undergoing bariatric surgery are women, approximately half of whom are of reproductive age. The most common procedure in the United States is the Roux-en-Y gastric bypass. Small bowel obstruction is one of many recognized postoperative complications. For such a serious condition, this entity presents with remarkable subtlety and is easily misdiagnosed, particularly in pregnant women. The consequences of late recognition can be life-threatening to both mother and fetus. We aim to decrease preventable maternal and perinatal morbidity and mortality by revealing diagnostic and therapeutic missteps related to Roux-en-Y gastric bypass-associated small bowel obstruction.

Color Doppler ultrasound (CDU) in the diagnosis of obstructive hydronephrosis in pregnant women

PURPOSE

Color Doppler ultrasound (CDU) accuracy of kidneys and bladder in the diagnosis and treatment of hydronephrosis and/or renal colic in pregnancies was evaluated.

METHODS

Between January 2010 and September 2012, 234 pregnant women asymptomatic in 204 cases and with unilateral renal colic in 30 (median 26 years) were evaluated. A CDU of the urinary tract was performed using a sonograph GE Logiq 500 PRO with a multifrequency (3-5 MHz) convex probe. The following parameters were evaluated: resistive index (RI) of the arciform arteries of both kidneys and bilateral ureteric jets. A renal RI > 0.70 and/or a 10 % difference between the kidneys and an asymmetric and/or reduced ureteric jet from the ureteric orifices were considered as diagnostic of obstructive uropathy.

RESULTS

Overall incidence of hydronephrosis was equal to 27 % (63 out 234 cases); the incidence of hydronephrosis, RI > 0.70 and abnormal ureteric jet in asymptomatic vs symptomatic pregnant women was equal to 30.9 vs 50 %, 16.1 vs 50 %, 3 vs 60 % (p < 0.05), respectively. In the 63 pregnancies with asymptomatic hydronephrosis RI and ureteric jet evaluation were abnormal in 39 (19.1 %) and 6 cases (3 %), respectively. In the 30 pregnancies with renal colic conventional ultrasound vs CDU, findings were abnormal in 15 (50 %) vs 20 (66.7 %) (p = 0.015) cases, respectively.

CONCLUSIONS

Color Doppler ultrasound in pregnancies with hydronephrosis and/or renal colic improves conventional ultrasound accuracy; in fact, CDU adds a functional evaluation of the urinary tract when combined with clinical findings allows performing the appropriate management.

Imaging the pregnant patient with abdominal pain

Imaging of pregnant patients with non-obstetric abdominal pain is reviewed, with an accompanying pictorial essay of cases with concentration on magnetic resonance imaging. Non-obstetric causes of abdominal pain during pregnancy are similar to those of non-pregnant patients. The most common causes are appendicitis and cholecystitis. Other causes are myriad and include biliary, gastrointestinal, infectious, inflammatory, and malignant etiologies, among others. The approach to imaging in pregnant patient is unique, as it is imperative to minimize potentially harmful radiation exposures to the fetus. Ultrasound and MRI are the primary modalities for evaluation of the pregnant patient with abdominal pain. The use of intravenous contrast is discouraged, except in highly-selected patients where there is no other way to obtain vital diagnostic information. CT is still used as the mainstay of evaluation of blunt abdominal trauma and is commonly used for diagnosis of small bowel obstruction, stone disease, and work-up of malignancy during pregnancy. A discussion of test selection and underlying rationale is presented.