Postoperative complications of colorectal cancer
Pallan A, Dedelaite M, Mirajkar N, Newman P.A, Plowright J, Ashraf S
Clinical Radiology. July 2021. DOI: doi.org/10.1016/j.crad.2021.06.002
Colorectal cancer (CRC) imaging, both pre and post op, has become a more common and complex imaging finding. Sound radiological and surgical knowledge is required to promptly detect and aid manage of post-surgical complications as colorectal surgery is associated with high morbidity of 35%, and mortality of 1-16.4% [1].
This educational review article, in the first part illustrates in a detailed yet diagrammatic style, the type of colorectal surgeries. The second part of the review, focuses on the post-operative complications which are logically described with their incidence together with which imaging techniques are best suited to identify these complications.
Surgeries are described in detail and include traditional surgeries like segmental resection, Hartmann’s procedure, anterior resection, abdominoperineal resection and new minimal invasive procedure’s such as trans-anal endoscopic microsurgery (TEMS) and trans-anal minimally invasive surgery (TAMIS). The descriptions and illustrations including the anatomy are easy to understand and will help guide the radiologist; particularly of note was a systematic explanation of different type of anterior resection depending on the level tumour. Those who may not have done a surgical rotation in the past would benefit from these.
Second part of the review focuses on complications; firstly focusing on anastomosis leak (AL) as a common complication with a rate of 1-19 % [2]. Interestingly the paper divided the leaks into three clinical grades A to C as this effects clinical management [8], and the review also categorised these in terms of onset after surgery. Lower rectal anastomoses are associated with higher leak rates [ 3,4]. CT with intravenous contrast medium (CECT) and endoluminal contrast medium is the preferred imaging modality in diagnosing AL and is superior to water-soluble contrast medium enema (WSCE) [4]. Tabulation of the imaging protocol provided for use on left and right sided anastomosis was given. There was a good description of radiological findings with appropriate illustration; these were further separated by what to expect given the number of post-operative days. The pitfalls of using WSCE was described.
Multiple modalities can be used to characterise fistula along with associated findings. Although the review describes fluoroscopic fistulography as excellent in visualising the tract, it is limited in use of extra luminal findings. The review compares use of CECT with both oral and direct luminal contrast with MRI. MRI was suggested to be useful for diagnosing chronic fistulation.
Associated collections, anatomical distortion or inflammatory change are seen with both CT and MRI. It was suggested luminal distension when using MRI with water-based soluble solution can aid diagnosis. These practices however vary depending on local protocol and individuals.
Post-operative strictures are common with incidence of between 3-30% [5]. The review clearly identified risk factors that would help the radiologist plan studies; with ischemia, previous anastomotic leak and radiotherapy quoted as risk factors. Although they can be identified on either WSCE, CT colography or water enema CT examinations, the radiological features are universal as described in the review as short, smooth narrowing with normal mural thickness and no extra luminal mass. There are very useful illustration in multiple modalities in the review.
Although a rare complication (0.5-4.9%), post-operative bleeding can be serious [6,7]. The paper gives a detail illustration on use of multiphasic CECT with high flow rate to aid diagnosis of active bleeding. There is an adequate explanation on the type of vascular injury to be expected depending on the type of surgery that has been performed as well as pointers to make note previous history of radiotherapy. This provides a good illustration on where to look out for the bleed. Interestingly left sided colonic resection was noted to be associated with an iatrogenic injury of the spleen at rate of 1.1% and right hemi-colectomies associated with a 1.6% incidence of injury of the superior mesenteric vein.
Intestinal obstruction findings are reviewed in detail. Plain radiograph was quoted to identify up to 60% of obstruction cases and one could argue that this simple test could remain the initial modality of choice. Intraluminal fluid in obstruction was suggested to provide neutral luminal contrast medium. The paper later went on to state a further advantage that CECT alone without oral contrast of being 95% specific for ischemia. Interestingly the paper has stated that if there is bowel wall enhancement and no mesenteric stranding, bowel ischemia can be confidently excluded.
Brief review and illustration of adhesions, ileus and hernia as well as stoma complications were also described. Although iatrogenic genitourological injury following CRC resection is rare, there was an in-depth review with excellent illustration and description.
This review article is logically structured, provides not only excellent anatomical illustration of surgical methodology but also good illustration of potential CRC surgical complications together with discussion on how best to image these. Those radiologists who may have not had a background in surgery will benefit the most from the first half of the review. There are however no illustrations on complications specifically related to minimal invasive surgery. In addition, medium to longer term post op complication and recurrence symptoms can overlap; this paper does not help guide the reader on when these should be suspected or how to modify imaging techniques to aid diagnosis.
References:
- Tevis SE, Kennedy GD. Postoperative complications: looking forward to a safer future. Clin Colon Rectal Surg 2016;29(3):246e52.
- McDermott FD, Heeney A, Kelly ME, et al. Systematic review of preoperative, intraoperative and postoperative risk factors
- Hyman N, Manchester TL, Osler T, et al. Anastomotic leaks after intestinal anastomosis: it’s later than you think. Ann Surg 2007;245(2):254e8.
- Khan AA, Wheeler JM, Cunningham C, et al. The management and outcome of anastomotic leaks in colorectal surgery. Colorectal Dis 2008;10(6):587e92
- Luchtefeld MA, Milsom JW, Senagore A, et al. Colorectal anastomotic stenosis results of a survey of the ASCRS membership. Dis Colon Rectum 1989;32(9):733e6.
- Martinez-Serrano MA, Pares D, Pera M, et al. Management of lower gastrointestinal bleeding after colorectal resection and stapled anastomosis. Tech Coloproctol 2009;13(1):49e53.
- Golda T, Zerpa C, Kreisler E, et al. Incidence and management of anastomotic bleeding after ileocolic anastomosis. Colorectal Dis 2013;15(10):1301e8.
- Rahbari NN, Weitz J, Hohenberger W, et al. Definition and grading of anastomotic leakage following anterior resection of the rectum: a proposal by the International Study Group of Rectal Cancer. Surgery 2010;147(3):339e51.
Dr. Muhammad Bilal Fayyaz is working as an Associate Specialist at Chesterfield Royal NHS trust since 2020 with a sub-specialty interest in GI, Paediatrics and IR. He graduated from Khyber Medical College, Peshawar, Pakistan in 2010. Afterwards, he completed his radiology training in Shaukat Khanum Memorial Cancer Hospital, in Lahore (2013-2018). He did a fellowship in Paediatric Interventional Radiology at Alder Hey Children NHS trust, Liverpool, UK in 2019. He is currently working alongside an experienced team of GI radiologists including Dr. Rajiv Karia.
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