ANATOMICAL VARIATIONS OF THE SUPERIOR MESENTERIC ARTERY AND ITS CLINICAL AND SURGICAL IMPLICATIONS IN HUMANS

SILVA, Natasha Gabriela Oliveira da; BARBOSA, Ana Beatriz Marques; SILVA, Nathalie de Almeida; ARAÚJO, Diego Neves; ASSIS, Thiago de Oliveira

doi:10.1590/0102-672020190001e1508

Different morphological patterns of SMA

ABSTRACT

Introduction:

Superior mesenteric artery (SMA) usually arises from the abdominal aorta, just below the celiac trunk and it supplies the midgut-derived embryonic structures. Anatomical variations in this vessel contribute to problems in the formation and/or absorption of this part of the intestine and its absence has been recognized as the cause of congenital duodenojejunal atresia.

Objective:

To analyze SMA anatomical variations in humans and the possible associated clinical and surgical implications.

Methods:

This is a systematic review of papers indexed in PubMed, SciELO, Springerlink, Science Direct, Lilacs, and Latindex databases. The search was performed by two independent reviewers between September and December 2018. Original studies involving SMA variations in humans were included. SMA presence/absence, level, place of origin and its terminal branches were considered.

Results:

At the end of the search, 18 studies were selected, characterized as for the sample, method to evaluate the anatomical structure and main results. The most common type of variation was when SMA originated from the right hepatic artery (6.13%). Two studies (11.11%) evidenced the inferior mesenteric artery originating from the SMA, whereas other two (11.11%) found the SMA sharing the same origin of the celiac trunk.

Conclusion:

SMA variations are not uncommon findings and their reports evidenced through the scientific literature demonstrate a great role for the development of important clinical conditions, making knowledge about this subject relevant to surgeons and professionals working in this area.

HEADINGS:
Mesenteric artery, superior; Anatomy; Intestinal atresia; Intestinal obstruction; Anatomic variation

[1] Correspondence: Thiago de Oliveira Assis Email: thiago.oa@hotmail.com

STUDIES	EVALUATION CRITERIA
STUDIES	1	2	3	4	5	6	7	8	9	10	11	12	Total (%)
Farghadani et al. (2016)	2	1	2	2	2	NA	2	2	2	2	2	2	95.45
Fonseca Neto et al. (2017)	1	2	2	1	2	NA	1	0	2	2	1	1	68.18
Gamo et al. (2016)	2	2	2	2	2	NA	2	2	2	2	2	1	95.45
Gomes et al. (2014)	1	NA	1	0	1	NA	0	0	0	1	1	0	25.00
Jain e Motwani et al. (2013)	2	0	2	1	1	NA	2	2	1	2	2	2	77.27
Kitamura et al. (1987)	1	NA	2	1	1	NA	0	0	1	2	0	0	40.00
Koops et al. (2004)	2	2	2	2	2	NA	2	2	2	1	2	1	90.90
Matusz et al. (2013)	2	NA	2	1	1	NA	2	0	2	2	2	2	80.00
Olave et al. (2009)	2	1	1	2	1	NA	1	1	2	2	1	1	68.18
Olga et al. (2010)	2	1	2	2	2	NA	2	2	2	2	2	2	95.45
Saša et al. (2016)	2	NA	2	0	1	NA	1	1	2	1	0	1	60.00
Sebben et al. (2013)	2	1	2	1	1	NA	1	1	2	2	2	1	72.72
Taha et al. (2017)	2	NA	1	0	1	NA	0	0	1	1	0	2	40.00
Torres et al. (1999)	0	NA	1	0	1	NA	1	0	0	1	0	0	20.00
Weber e Freeman (1999)	2	NA	1	0	1	NA	1	0	0	0	0	1	30.00
Wu et al. (2014)	2	NA	2	1	1	NA	1	1	2	0	0	1	55.00
Yakura et al. (2017)	1	NA	2	0	1	NA	1	0	2	1	0	1	45.00
Yoo et al. (2011)	2	NA	2	0	1	NA	0	0	2	1	1	1	50.00

Author (year)	Sample	Methods	Main Results
Farghadani et al. (2016)	607 patients	Computed tomography	Three hundred and eighty-eight (63.9%) of the 607 patients had classic SMA anatomy and 219 (36.1%) had variant types, the most common type was the one from the right hepatic artery (9.6%).
Fonseca Neto et al. (2017)	479 patients	Vascular analysis of deceased liver donors	Four hundred and sixteen patients (86.84%) had normal arterial anatomy. The other 63 patients (13.15%) presented anatomical variation. Of these, 27 presented the superior mesenteric artery originating the right hepatic artery, whereas other 4 presented the right hepatic artery resulting from the superior mesenteric artery while the left hepatic artery originated from the left gastric artery.
Gamo. et al. (2016)	Sample #1: 28 men and 22 women (cadavers); Sample #2: 399 men and 161 women (alive)	Human cadaveric dissection and computed tomography	The variations found were classified into two types. In type I, SMA originated the middle colic artery (MCA), right colic (RCA) and ileocolical (ICA) in 40% of cadavers dissected and 73.69% of the CT scan (computed tomography). In type II, there are three distinct patterns: in the IIA, ICA arises separately (found in 20% of the dissected cadavers and 4.28% of the CT sample), in IIB the MCA is the one that arises separately (found in 32% of the cadavers dissected and 15% of the CT sample) and in the IIC, MCA, RCA and ICA appear from the common trunk (present in 0.35% of CTs and absent in cadavers).
Gomes et al. (2014)	One male cadaver	Cadaveric dissection	The common hepatic artery originated from the superior mesenteric artery, located 3.5 cm below and lateral to the celiac trunk, forming a hepatomesenteric trunk.
Jain and Motwani (2013)	20 cadavers	Cadaveric dissection	14 cadavers (70%) presented a normal SMA branch pattern, 5 cadavers (25%) had a common trunk for the ileocolic and right colonic arteries coming out of SMA, while 1 cadaver (5%) presented the rarest variation in the pattern of SMA branching: a common trunk of the left colonic artery with an accessory splenic artery arising from its anterior face, rather than from the inferior mesenteric artery.
Kitamura et al. (1987)	A 69-year-old Japanese cadaver	Cadaveric dissection	SMA originated the inferior mesenteric artery, which usually originates from the abdominal aorta. And although it emerged from SMA, it had the same branches as a lower mesenteric artery.
Koops et al. (2004)	604 patients	Analysis of superior celiac and mesenteric angiograms	The arterial anatomy considered normal in the literature was found in 79.1% of the exams. The aberrant right or accessory hepatic artery (RHA) branched out from the superior mesenteric artery in 11.9% of the cases.
Matusz et al. (2013)	A 44-year-old man	Computed tomography angiotomography	The celiac trunk and the superior mesenteric artery originate from the thoracic aorta (TA) 21 mm and 9 mm above the aortic hiatus, respectively. The SMA descends both at the thoracic and abdominal level, making a 17º angle, and having an aortomesenteric distance of 9 mm at the level of the third part of the duodenum.
Olave et al. (2009)	31 Chileanpatients, adults	Helical computed tomography	The superior mesenteric artery was found in 100% of the cases. The level of origin was always cranial to the origin of the renal arteries. The level of origin of the superior mesenteric artery was observed compared to LI vertebra in 16 cases and in the L2 vertebra in 8 cases.
Kornafel et al. (2010)	201 patients (91 womenand 110 men)	Computed tomography angiography	In 88 patients (43.8%), there were anatomical variations of the branched arteries from the abdominal aorta, including superior mesenteric artery variations in 4 (2%) patients. The common origin of the celiac trunk and the superior mesenteric artery - the celiac-mesenteric trunk - was observed in 3 patients (1.5%). The simultaneous presence of the gastroesplenic trunk and the hepatomesenteric trunk was found in 1 patient (0.5%).
Saša et al. (2016)	A prematureinfant (29 weeks)	Ultrasonographyand Abdominal Radiography	Investigation of the abdominal cavity revealed duodenal atresia in the second portion of the duodenum with absence of the third and fourth portions, as well as absence of the superior mesenteric artery and jejunum apple peel atresia.
Sebben G. et al. (2013)	45 cadavers	Cadaveric dissection	Among the 45 cadavers analyzed, 7 presented anatomical variations related to SMA. In three cases, the right hepatic artery originated from SMA, corresponding to 10% of the sample. In two of the cadavers, the SMA originated the common hepatic artery. It was also found a single case of the left hepatic artery arising from SMA and one case of SMA originating the gastroduodenal artery.
Taha et al. (2017)	A Sudanese male cadaver	Cadaveric dissection	SMA was observed by forming an arch over the confluence of the inferior vena cava and left renal vein. Other variations were found: 1) The SMA shared the same origin as the celiac trunk; 2) The unusual origin of the right hepatic artery.
Torres et al. (1999)	34-week newborn with intestinal atresia	Ultrasonographyand Abdominal Radiography	Ultrasound examination of the abdomen suggested the absence of SMA shortly after its removal from the abdominal aorta and with hypertrophy of the celiac axis. The two distal thirds of the transverse, descending and rectosigmoid colon were present. No calcifications were observed in the abdominal cavity, as occasionally occurs with intestinal atresia.
Weber and Freeman (1999)	36-week newborn with duodenojejunal atresia	Laparotomy	There was loss of the third and fourth parts of the duodenum due to the absence of the SMA branch. The distal segment of the ileum is shortened and assumes the helical configuration around a retrograde perfusion vessel, which compensates for the missing SMA. This case involved complete obliteration of SMA together with associated duodenal atresia.
Wu Y et al. (2014)	A 69-year-old woman	Computed tomography	The study revealed the complete absence of SMA and compensatory dilation of the inferior mesenteric artery. The aneurysm of the splenic artery and the inferior phrenic arteries that emerged aberrantly from the aorta on the same level of the celiac trunk were also observed.
Yakura et al. (2017)	An 86-year-old female cadaver	Cadavericdissection	SMA originated the cystic artery. The middle colonic artery was absent and the left colonic artery, branching from the inferior mesenteric artery, was distributed along the entire length of the transverse colon.
Yoo et al. (2011)	An 82-year-old Korean female cadaver	Cadavericdissection	SMA gave the inferior mesenteric artery as its second branch. The longitudinal vessels of the anastomosis between the superior mesenteric artery and the inferior mesenteric artery survived to form the common mesenteric artery.

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