Coronary vasodilation by the use of sublingual nitroglycerin using 64-slice dual-source coronary computed tomography angiography

Effectiveness of the proximal medial branch in DIEP flaps for breast reconstruction using Hartrampf zone IV

BACKGROUND

When performing breast reconstruction using a deep inferior epigastric artery (DIEA) perforator (DIEP) flap, including Hartrampf zone IV, the bipedicled DIEP flap has been argued to be necessary to ensure stable perfusion. However, a proximal medial branch (PMB), which is the most proximal perforator of DIEA, may make it possible to obtain adequate perfusion in a unilateral DIEP flap. This study aimed to clarify the detailed anatomical characteristics of PMB and its potential clinical applications in breast reconstruction.

METHODS

This retrospective study was conducted on breast reconstruction using the DIEP flap between May 2020 and July 2023. Data on PMB anatomy were collected from preoperative contrast-enhanced computed tomography angiography, and contralateral perfusion of the flap was estimated using intraoperative indocyanine green angiography.

RESULTS

PMB was present in approximately 85% of the cases, arising near the lateral border of the rectus abdominis, branching caudomedially in more than half of the cases, and perforating 2.3 cm laterally and 8.8 cm caudally, on average, from the umbilicus. The average perfusion area of zones II and IV significantly expanded to 96.5% and 74.2%, respectively, when PMB was included in the DIEP flap, and 9 of 22 cases showed contrast extending to the entire zone IV.

CONCLUSIONS

The use of the DIEP flap with PMB is a good option for substantial-volume breast reconstruction. When utilizing PMB, it is important to consider its specific anatomy, location of the main perforator, and pedicle length.

Computed tomography angiography assessment of Adamkiewicz artery with sublingual nitroglycerin administration

PURPOSE

Identification of the Adamkiewicz artery before aortic surgery is important for preventing postoperative complications due to spinal cord ischemia. The Adamkiewicz artery is difficult to identify due to its small diameter. Nitroglycerin has a vasodilatory effect and is used clinically to improve visualization of blood vessels on coronary computed tomography (CT) angiography. We investigated whether the vasodilatory effect of nitroglycerin could improve the ability to visualize the Adamkiewicz artery.

METHODS

We extracted 33 cases wherein contrast-enhanced CT images were taken before and after aortic aneurysm surgery. Nitroglycerin was administered for coronary artery evaluation on the preoperative CT. However, no nitroglycerin was administered before the postoperative CT. Aortic contrast-to-noise ratio, CT value, image noise, and diameter of the Adamkiewicz artery and anterior spinal artery were measured. The depiction of the Adamkiewicz artery was graded into four grades and evaluated. These measurements were performed by two independent reviewers.

RESULTS

In nitroglycerin-administered cases, the contrast-to-noise ratio and CT values were significantly higher (P < 0.001, P < 0.001, respectively); the Adamkiewicz artery and anterior spinal artery diameters were dilated (P = 0.005, P = 0.001, respectively). The Adamkiewicz artery score also improved significantly (P < 0.001). No significant difference was found in image noise.

CONCLUSION

Nitroglycerin contributed to improving the Adamkiewicz artery's visualization.

Improving the visualisation of perforator arteries for anterolateral thigh flaps harvest in CT angiography via sublingual glyceryl trinitrate

AIM

To investigate the improvement of image quality and visualisation of the anterolateral thigh (ALT) flap perforators on computed tomography angiography (CTA) after administration of sublingual glyceryl trinitrate (GTN).

MATERIALS AND METHODS

Sixty patients with oral lesions received thigh CTA examinations were divided randomly into two groups after administration of sublingual GTN (GTN group) or without administration of sublingual GTN (non-GTN group). Two radiologists calculated the signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and assessed the image quality of each vessel. Besides, the grade of thigh artery, the lumen diameter of deep femoral artery, lateral circumflex femoral artery (LCFA), the descending branch of LCFA and its proximal and distal perforators, and the number and type of visible perforators were evaluated quantitatively.

RESULTS

The SNR and CNR were not significantly different between the two groups (p>0.05). The image quality of CTA in the GTN group was significantly better than that in the non-GTN group (p<0.01). The lumen diameters of the deep femoral artery, LCFA, the descending branch of LCFA and its perforators were significantly larger in the GTN group than those in the non-GTN group (p<0.01). Compared with the non-GTN group, the number of visible perforators and the number of visible septocutaneous perforators were significantly more in the GTN group, and the qualitative grade of visible perforators was significantly higher (p<0.001).

CONCLUSIONS

The administration of sublingual GTN in preoperative thigh CTA can improve the image quality and visualisation of perforator vessels, thus could help surgeons to select the optimum ALT flaps.

Nitroglycerin improves the visibility of fibula-free flap perforators on computed tomography angiography in patients with oral or maxillofacial lesion

PURPOSE

To investigate the improvement of image quality and visualization of fibula-free flap (FFF) perforators on computed tomography angiography (CTA) after administration of sublingual nitroglycerin (NTG) tablets.

METHODS

A total of 60 patients with oral or maxillofacial lesions before CTA of the lower extremity were randomly divided into two groups (NTG group and non-NTG group). The signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR), overall image quality and grading of vessels were evaluated and compared. The lumen diameters of the major arteries and the proximal and distal peroneal perforators were measured. The number of visible perforators in muscular clearance and muscular layer was also counted and compared between the two groups.

RESULTS

The CNR of posterior tibial artery and overall image quality of CTA images in the NTG group was significantly higher than that in the non-NTG group (p < 0.05), although the SNR and CNR of other arteries did not show significant differences (p > 0.05). The lumen diameters of the peroneal artery and its perforators, anterior tibial artery, and posterior tibial artery were significantly larger in the NTG group (p < 0.001), while no significant difference prevailed in the diameter of the popliteal artery between the two groups (p = 0.298). Compared with the non-NTG group, a significant increase in the number of visible perforators was noted in the NTG group (p < 0.001).

CONCLUSIONS

The administration of sublingual NTG in CTA of the lower extremity can improve the image quality and visualization of perforators, which aids to surgeons select the optimum FFF.

Can Sublingual Nitrate Improve Visualization of Lower Limb Arteries on Computed Tomography Angiography?

OBJECTIVE

The aim of the study is to evaluate the role of sublingual nitrate in improving vessel visualization on peripheral computed tomography angiography (CTA).

METHODS

Fifty patients clinically diagnosed with peripheral arterial disease of the lower limb were prospectively included in this study: Twenty-five underwent CTA after sublingual nitrate administration (nitrate group) and 25 without (non-nitrate group). Two blinded observers qualitatively and quantitatively assessed the data thus generated. The mean luminal diameter, intraluminal attenuation, site, and percentage of stenosis were evaluated in all segments. Assessment of collateral visualization at sites of significant stenosis was also done.

RESULTS

Patients in the nitrate and non-nitrate groups were similar in age and sex characteristics (P > 0.05).On subjective evaluation, there was significantly improved visualization of the femoropopliteal and tibioperoneal vasculature of the lower limb in the nitrate group compared with the non-nitrate group (P < 0.05). Quantitative evaluation showed a statistically significant difference in the measured arterial diameters for all evaluated segments in the nitrate group versus the non-nitrate group (P < 0.05). Intra-arterial attenuation was significantly greater for all segments in the nitrate group resulting in better contrast opacification in these studies. Collateral visualization around segments with more than 50% stenosis/occlusion was also better in the nitrate group.

CONCLUSIONS

Our study suggests that nitrate administration before peripheral vascular CTA can improve visualization, especially in the distal segments by increasing the vessel diameter and intraluminal attenuation along with better delineation of the collateral circulation around stenotic areas. It may also improve the number of evaluable segments of vasculature in these angiographic studies.

The Effect of Clinically Indicated Liraglutide on Pericoronary Adipose Tissue in Type 2 Diabetic Patients

Vascular inflammation can be detected in the pericoronary adipose tissue (PCAT) by coronary computed tomography angiography (CCTA) attenuation. Treatment with liraglutide is associated with anti-inflammatory effects and reduces cardiovascular risk in diabetic patients. This study is aimed at examining the effect of clinically indicated liraglutide on PCAT attenuation. Asymptomatic patients with type 2 diabetes mellitus (T2DM) and without known ischemic heart disease underwent clinical examination, blood analysis, and CCTA. The main coronary arteries were outlined and PCAT attenuation was measured on the proximal 40 mm. Patients treated with liraglutide on a clinical indication were compared to patients not receiving liraglutide. The study included 190 patients; 53 (28%) received liraglutide (Lira+) and 137 (72%) did not (Lira-). There were no significant differences in PCAT attenuation between the two groups in either artery. However, PCAT attenuation measured around the left anterior descending artery (LAD) was lower in the Lira+ group after adjustment for age, sex, body mass index, and T2DM duration (b coefficient -2.4, p = 0.029). In a population of cardiac asymptomatic T2DM patients, treatment with clinically indicated liraglutide was not associated with differences in PCAT attenuation compared to nonliraglutide treatment in the unadjusted model. An association was seen in the adjusted model for the left anterior descending artery, possibly indicating an anti-inflammatory effect.

Assessment of coronary spasms with transluminal attenuation gradient in coronary computed tomography angiography

Purpose

To evaluate the imaging features of coronary spasm, including transluminal attenuation gradient (TAG) on coronary computed tomography angiography (CCTA), in patients with vasospastic angina (VA).

Methods

A total of 43 patients with a high clinical likelihood of VA were included in the study. All the subjects underwent double CCTA acquisition: CCTA without a vasodilator (‘baseline CT’) and CCTA during continuous intravenous nitrate infusion (‘IV nitrate CT’). A catheterized ergonovine provocation test was used to determine true VA patients. Coronary spasm is classified into focal- and diffuse-types according to morphological differences. We measured TAG and contrast enhancement of the proximal ostium (ProxHU) of each coronary artery for both the baseline and IV nitrate CT.

Results

Twenty-four patients (55.8%) showed positive results of coronary vasospasm on the provocation test. Thirty-eight vessels showed coronary spasms (29.5%): Focal-type in nine vessels (24%), and diffuse-type in 29 (76%). In the baseline CT, LCX showed significantly lower (steeper) TAG in spasm(+) vessels than in spasm(-) vessels, while LAD and RCA showed no significant differences in TAG. The ProxHU of LAD showed significantly lower values in spasm(+) vessels than in spasm(-) vessels, while the other vessels did not show significant differences in ProxHU. For IV nitrate CT, there were no significant differences in either the TAG and ProxHU between spasm(+) and (-) vessels for all the three vessel types. In subgroup analysis for spasm(+) vessels, diffuse spasms showed significantly lower TAG than focal spasms, while the ProxHU did not differ between the two types of spasm.

Conclusions

A relatively large percentage of coronary spasms present as diffuse type, and the TAG values significantly differed according to the morphological type of the coronary spasm.

The timing of administering aspirin and nitroglycerin in patients with STEMI ECG changes alter patient outcome

BACKGROUND

Both chewed aspirin and sublingual nitroglycerin are fast acting medications and reach therapeutic levels within a few minutes. Current guidelines for managing acute coronary syndrome (ACS) do not recognize the importance of the order or timing of administering aspirin and nitroglycerin. This retrospective study aimed to examine if there was any benefit to the timing of giving aspirin before or after nitroglycerin in cases of ACS.

METHODS

From the large National Emergency Medical Services Information System (NEMSIS) 2017 Version database, 2594 patients with acute coronary syndrome were identified (based on chest pain and their ECG finding) that received aspirin plus nitroglycerin in prehospital settings. Based on which medication was given first, the patients were separated in 2 groups: an aspirin-first and a nitroglycerin-first group. The 2246 patients who received aspirin first were further stratified based on the time between administration of aspirin and the first dose of nitroglycerin. The other 348 patients who received nitroglycerin first were similarly stratified.

RESULTS

In patients with STEMI ischemia, giving nitroglycerin 10 min after aspirin dosing (compared to giving them simultaneously) leads to a greater than 20% reduction in need for additional nitroglycerin, a greater than 7% decrease in subjective pain experienced by the patient and reduced need for additional opioids. The aspirin-first group in total, had a 39.6% decrease in subjective pain experience after giving additional nitroglycerin compared to nitroglycerin-first group.

CONCLUSION

In patients with ACS, this study found that giving nitroglycerin 10 min after aspirin was associated with a reduction in subjective pain scores, as well as a reduced need for additional nitroglycerin or opioids. Future prospective trials examining the timing of aspirin vs. nitroglycerin are needed to confirm these findings.

Using 320-detector row computed tomography angiography to investigate the arterial anatomy of the toe flaps on living humans

PURPOSE

Using 320-detector row computed tomography angiography (320-CTA) to investigate the arterial supply for the toe flaps, namely the anatomical characteristics of the dorsalis pedis artery (DPA), the first dorsal metatarsal artery (FDMA), and the arteries of the first toe web space (AsFTWS).

METHODS

This was a prospective study on CTA of 72 intact feet of 36 Vietnamese adults who had sequelae of thumb or metacarpal hand amputation, from June 2017 to December 2019, then preoperative CTA images were compared with surgical findings on 31 feet of 29 patients.

RESULTS

320-CTA was able to investigate the DPA, FDMA, and AsFTWS in 100% of cases. DPA was absent in 6.9% of cases. The average diameters at its origin and termination were 3.22 and 2.56 mm, respectively. For FDMA, the rates of Gilbert type I, II, and III were 52.8%, 18.1%, and 29.2%; the average diameters at its origin and termination were 1.98 and 1.67 mm, respectively. At the first toe web space, FDMA was dominant in 54.2% of cases; the first plantar metatarsal artery (FPMA) was dominant in 29.2% of cases; both arteries were equally dominant in 16.6%. The average diameter at the origin of the lateral plantar digital artery of the great toe was 1.48 mm, of the medial plantar digital artery of the second toe was 1.21 mm. Preoperative CTA images resembled the surgical findings in all cases. The survival rate of toe flaps was 100%.

CONCLUSION

The 320-CTA provided proper preoperative images in two and three dimensions, and helped surgeons to establish a preoperative surgical plan, thus increasing the success rate of toe transfer surgery.

Quantitative evaluation of coronary artery visibility on CT angiography in Kawasaki disease: young vs. old children

Coronary artery visibility on coronary CT angiography has rarely been investigated in young children with Kawasaki disease. This retrospective study was performed to quantitatively evaluate and compare coronary artery visibility with sufficient quality to measure it on coronary CT angiography among younger and older children with Kawasaki disease. Seventy-eight consecutive children with Kawasaki disease who underwent coronary CT angiography were divided into two groups: group 1 (age ≤ 6 years; n = 37) and group 2 (age > 6 years and < 18 years; n = 41). The visibility of the right coronary artery, left anterior descending artery, and left circumflex artery was quantitatively evaluated by dividing the length of the assessable coronary artery by the length of the corresponding groove, and compared between the two groups. The coronary artery visibility in group 1 was significantly lower than that in group 2 for the right coronary artery (77.8 ± 26.3% vs. 94.2 ± 13.6%, p < 0.002) and left anterior descending artery (54.8 ± 19.5% vs. 69.6 ± 21.3%, p < 0.003, but the difference was not significant for the left circumflex artery (43.7 ± 23.1% vs. 43.9 ± 26.7%, p > 0.9). In both groups, the visibility of the right coronary artery was the highest, followed by those of the left anterior descending artery and left circumflex artery. Compared with older children with Kawasaki disease, younger children with Kawasaki disease demonstrate significantly lower visibility of the right coronary artery and left anterior descending artery on coronary CT angiography. In contrast, the visibility of the left circumflex artery showed no significant difference between younger and older children with Kawasaki disease.

Nitrates administered by spray versus tablet: comparison of coronary vasodilation on CT angiography

OBJECTIVES

To compare the coronary vasodilation effects of spray with those induced by tablet administration in coronary CT angiography (CCTA).

METHODS

A total of 2024 patients who underwent CCTA were identified for this retrospective study, including 828 patients with spray (spray group) and 1169 with tablets (tablet group). Of these, 93 patients underwent CCTA at least twice using both spray and tablets. The number of measurable segments and diameters of all 18 segments was measured. The number of measurable segments was compared between groups.

RESULTS

No statistically significant differences were evident between these two groups in terms of clinical characteristics. All coronary segments except the ramus intermedius (RI) and left posterior descending artery (L-PDA) were significantly larger in the spray group than in the tablet group (all p < 0.001). In peripheral and branch vessels, as well as in central and main coronary arteries, the diameters were significantly larger in the spray group than in the tablet group (all p < 0.001). Although not always statistically significant, all coronary segments tended to be more measurable on CCTA with spray than with tablet. In the subgroup that underwent CCTA twice using both spray and tablets, all coronary segments except the RI, obtuse marginal artery 2 (OM2), and L-PDA were significantly larger in the spray group than in the tablet group (all p < 0.05).

CONCLUSION

Lingual isosorbide dinitrate (ISDN) spray was more efficacious than sublingual nitroglycerin (NTG) tablets in coronary vasodilation for CCTA. Therefore, lingual ISDN spray should be preferred over sublingual NTG tablets for CCTA.

KEY POINTS

• Lingual ISDN spray was more efficacious than sublingual NTG tablet for coronary vasodilation in coronary CT angiography, even in elderly patients. • The diameters of all coronary segments except RI and L-PDA were significantly larger, and there were significantly more coronary segments greater than 1.5 mm, except RI and L-PDA, in the spray group than in the tablet group in the whole study group. • Even in peripheral and branch vessels, the diameters of coronary arteries were significantly larger in the spray group than in the tablet group, and they were also larger in elderly patients.

The Effects of a Vasodilator on Transluminal Attenuation Gradient at Coronary Computed Tomography Angiography

Objective

To evaluate the effects of vasodilators on contrast enhancement and transluminal attenuation gradient (TAG) of coronary arteries at coronary computed tomography angiography (CCTA).

Materials and Methods

We retrospectively reviewed CCTA scans of patients who underwent double-acquisition CCTA; CCTA without a vasodilator, and CCTA during a intravenous (IV) infusion of nitrate. Among them, we enrolled 19 patients who had no significant atherosclerotic lesions or coronary spasms. In the control group, 28 patients were enrolled who showed normal coronary arteries on CCTA, which was acquired by a conventional method (sublingual vasodilator). We measured the TAG and Hounsfield units for each of the three major epicardial coronary arteries (reported as ‘ProxHU’) and then compared the results between the nitrate administration methods (CT without vasodilator [CT_pre], CT with IV vasodilator [CT_iv], and CT with sublingual vasodilator [CT_sub]).

Results

The mean TAG showed a significant difference between the coronary arteries (right coronary artery [RCA] > left anterior descending artery [LAD] > left circumflex artery [LCX], p < 0.05), while there was no difference in ProxHU of each coronary artery in all three types of nitrate administration methods (p > 0.05). The TAG of CT_pre group showed steeper slope than those of vasodilator groups (CT_iv and CT_sub) on LAD and LCX ([LAD: CT_pre = −22.1 ± 6.66, CT_iv = −16.76 ± 5.78, and CT_sub = −16.47 ± 5.78, p = 0.005], [LCX: CT_pre = −31.26 ± 17.43, CT_iv = −23.74 ± 14.06, and CT_sub = −20.94 ± 12.15, p = 0.051]), while that of RCA showed no significant differences (p = 0.600). When comparing proxHU, CT_iv showed higher proxHU than that of CT_pre or CT_sub, especially on LCX (CT_pre = 426.7 ± 68.3, CT_iv = 467.9 ± 84.9, and CT_sub = 404.9 ± 63.3, p = 0.013). ProxHU showed a negative correlation with TAG on all three of methods (r = −0.280, p < 0.001).

Conclusion

TAG in CCTA was significantly affected by vasodilator administration. Both TAG and ProxHU of coronary arteries tend to increase with vasodilator administration on CCTA.

Questionable necessity of nitroglycerin for diagnostic coronary artery examination using 320-row multi-detector computed tomography

OBJECTIVE

This study aims to analyze and compare the diagnostic effectiveness of 320-row multi-detector computed tomography for coronary artery angiography (MDCTA) in subjects with and without sublingual vasodilator (nitroglycerin).

MATERIALS AND METHODS

From September 2015 to September 2016, 70 individuals without history of major cardiovascular diseases who underwent MDCTA for health examination were retrospectively categorized into sublingual nitroglycerin (NTG) and non-NTG groups. Medical history, CT dose index (CTDI), and multi-slice CT images were compared between two groups. A diameter of coronary artery (DA, mm) was computed and analyzed.

RESULTS

A total of 41 males and 29 females (mean age: 55.43±8.84 years, range: 34- 76) were reviewed. Normal and abnormal MDCTA findings were noted in 54 and 16 participants, respectively, with the detection rate of coronary artery disease being 23%. There was no significant difference in inter-observer variability of coronary CTA image quality and diagnosis between the NTG and non-NTG groups among three experienced radiologists. Although the percentage dilatation of left anterior descending branch (LAD), right coronary artery (RCA) and left circumflex branch (LCX) following in the NTG group were 12.4%, 12.8% and 25.3%, respectively (p < 0.01), there was no significant difference in image quality and diagnosis between the two groups.

CONCLUSIONS

Despite the recommendation of routine nitroglycerin use for subjects undergoing computed tomography for coronary artery angiography, our results showed no significant advantage of its use in improving image quality and rate of diagnosis accuracy.

The Value of 16-cm Wide-Detector Computed Tomography in Coronary Computed Tomography Angiography for Patients With High Heart Rate Variability

OBJECTIVE

The aim of this study was to investigate radiation dose and image quality of coronary computed tomography (CT) angiography (CCTA) for patients with high heart rate variability (HRv) using 16-cm wide-detector CT scanner.

METHODS

One hundred sixty-six patients with uncontrolled heart rate underwent CCTA on a 16-cm wide-detector CT system and were divided into 2 groups based on their HRv for analysis: group A (n = 95, HRv ≤10 beats/min [bpm]) and group B (n = 71, HRv >10 bpm). Images in both groups were reconstructed with motion correction algorithm. Subjective and objective image qualities were analyzed.

RESULTS

There were no significant differences in age, body mass index, and heart rate (68.1 ± 11.4 vs 67.6 ± 12.3 bpm) between the 2 groups (P > 0.05). However, group B had significantly higher HRv than group A (33.5 ± 24.4 vs 7.8 ± 1.2 bpm, P < 0.001). All images were acceptable for clinical diagnosis. Compared with group A, image quality scores in group B decreased slightly (4.1 ± 0.5 vs 4.0 ± 0.6). However, the difference was not statistically significant. The mean effective doses were both relatively low at 2.2 ± 1.1 mSv in group A and 2.6 ± 1.4 mSv in group B.

CONCLUSIONS

Single-heartbeat free-breathing CCTA can be performed for patients with high HRv using 16-cm wide-detector CT scanner to achieve diagnostic image quality with low radiation dose.

Sublingual Nitroglycerin Administration in Coronary Computed Tomography Angiography: a Systematic Review

OBJECTIVE

To systematically investigate the literature for the influence of sublingual nitroglycerin administration on coronary diameter, the number of evaluable segments, image quality, heart rate and blood pressure, and diagnostic accuracy of coronary computed tomography (CT) angiography.

METHODS

A systematic search was performed in PubMed, EMBASE and Web of Science. The studies were evaluated for the effect of sublingual nitroglycerin on coronary artery diameter, evaluable segments, objective and subjective image quality, systemic physiological effects and diagnostic accuracy. Due to the heterogeneous reporting of outcome measures, a narrative synthesis was applied.

RESULTS

Of the 217 studies identified, nine met the inclusion criteria: seven reported on the effect of nitroglycerin on coronary artery diameter, six on evaluable segments, four on image quality, five on systemic physiological effects and two on diagnostic accuracy. Sublingual nitroglycerin administration resulted in an improved evaluation of more coronary segments, in particular, in smaller coronary branches, better image quality and improved diagnostic accuracy. Side effects were mild and were alleviated without medical intervention.

CONCLUSION

Sublingual nitroglycerin improves the coronary diameter, the number of assessable segments, image quality and diagnostic accuracy of coronary CT angiography without major side effects or systemic physiological changes.

KEY POINTS

• Sublingual nitroglycerin administration results in significant coronary artery dilatation. • Nitroglycerin increases the number of evaluable coronary branches. • Image quality is improved the most in smaller coronary branches. • Nitroglycerin increases the diagnostic accuracy of coronary CT angiography. • Most side effects are mild and do not require medical intervention.