Right internal thoracic or radial artery as the second arterial conduit for coronary artery bypass surgery.

PURPOSE OF REVIEW: To summarize the available evidence on the use of the right internal thoracic artery (RITA) and the radial artery as the second arterial graft in coronary artery bypass surgery. RECENT FINDINGS: The current data support the equipoise of the two conduits in terms of clinical and angiographic outcomes. Both RITA and radial artery have better patency than saphenous vein grafts. The use of the RITA carries an increased risk of deep sternal wound infection (DSWI) if the artery is harvested as pedicle. Bilateral internal thoracic artery grafting is more technically demanding than radial artery use and there is a volume-outcome relationship in terms of mortality and incidence of DSWI. The radial artery is preferable over RITA in right-sided or distal circumflex artery targets with high-degree stenosis and in patients at higher risk for DSWI, whereas it is not recommended to graft vessels with moderate stenosis and in cases of insufficient collateralization from the ulnar artery or previous transradial procedures. SUMMARY: The patency rate and clinical outcomes of radial artery and RITA are similar. The use of one or the other should be based on a careful evaluation of the patient's coronary anatomy and comorbidities, the conduit availability and the surgeon's and center's experience.

Distribution of internal thoracic artery perforators: A clincal anatomy study.

There are various modifications of the transverse rectus abdominis musculocutaneous flap and deep inferior epigastric perforator flap to reduce the morbidity of the donor site or to augment the vascularity of the flap. For microanastomosis of multiple pedicles, multiple recipient vessels or an intervening vein graft should be provided. In addition, alternative perforator-based flaps used in breast reconstruction have small caliber pedicles. Therefore, small recipient vessels such as internal thoracic artery perforators are more suitable for appropriate microanastomosis. Therefore, it is important to acquaint the distribution and anatomical characteristics of internal thoracic artery perforators. We researched the perforators running in the intercostal spaces under the pectoralis major muscle to provide an overview of the anatomical distribution and characteristics of the perforators in patients who underwent immediate subpectoral implant-based breast reconstructions. In our study, the major perforators (diameter > 1.5 mm) were easily found 2-7 cm medially between the third and fourth intercostal space and were sparse in the lateral area from the midline of the breast (usually 8-9 cm lateral to the midsternal line) and above the third rib. In each side of the breast, the average number of perforators greater than 1.5 mm was 1.6, and the average number of perforators between 1 mm and 1.5 mm in diameter was 3.2. Our results provide information about perforators in the anterior chest wall related to the breast area. Clin. Anat. 32:471-475, 2019. © 2018 Wiley Periodicals, Inc.

Proper Choice of Vessels for Supermicrosurgery Training: An Experimental Animal study.

BACKGROUND: Reconstruction using supermicrosurgery, a technique of microneurovascular anastomosis for smaller vessels (< 0.8 mm), has become popular. Experimental animal studies for supermicrosurgery training have been reported; however, there have been few studies performed according to vessel diameter and pedicle length. In this study, the external diameters of four vessels (femoral, superficial epigastric, axillary, and common thoracic) and pedicle length of two flaps (superficial epigastric and common thoracic-long thoracic) were measured. METHODS: The inguinal and pectoral regions of Sprague-Dawley rats (n = 19) were dissected anatomically, and the external diameters of the four vessels were measured (right and left, artery and vein measured separately). After elevating the superficial epigastric and common thoracic-long thoracic flaps, the pedicle length of the flaps was also measured. RESULTS: Among the 16 vessels examined, the external diameters of 11 and 5 vessels were above and below 0.8 mm, respectively. The external diameters of the superficial epigastric vessel and common thoracic vessel (both arteries and veins) were below 0.8 mm. The external diameters of the femoral and axillary vessels (veins) were above 0.8 mm. The length of the common thoracic-long thoracic pedicle was approximately10 mm longer than that of the superficial epigastric pedicle. CONCLUSIONS: The external diameters of the superficial epigastric vessel and common thoracic vessel are small enough for supermicrosurgery training. The pedicle lengths of both the superficial epigastric and common thoracic-long thoracic flaps are sufficient to perform free flap experiments. Supermicrosurgical free flaps using these two vessels and a study of the physiology and pharmacology of the flaps will likely be possible in the future.

Rerouting the internal thoracic pedicle: a novel solution for maxillofacial reconstruction in vessel-depleted situations? A preliminary anatomic study.

PURPOSE: Microsurgical reconstruction in a vessel-depleted neck is a challenge due to the lack of reliable vessels in or nearby the host site. The use of the internal thoracic pedicle (ITP) by rib section or sparring is a limited option due to the small length of the pedicle of some flaps. However, in cardiac surgery, the internal thoracic artery (ITA) is widely used for myocardial revascularization, providing a long and versatile pedicle. We aimed at determining precise anatomical bases for the use of the ITP, approached by sternotomy and rerouted in the neck, as recipient vessels for free-flap facial reconstructions. METHODS: We performed a descriptive single centre anatomical study on 20 formalin-embalmed cadavers. The ITP was harvested on both sides from the emergence of the artery under the brachiocephalic vein to its terminal division. The level reached by the ITP in the cervicofacial area was described. Distal arterial and venous diameters, pedicle length and other parameters were measured. RESULTS: In at least 85% of the cases, the ITP reached the mandibular angle. The mean diameter at the distal extremity for the ITA was 2.36 ± 0.15, and 2.48 ± 0.19 mm for the committing vein. The mean length of the ITP was 177.3 mm. CONCLUSION: Rerouting the ITP towards the cervicofacial area could provide a reliable pedicle for free-flap reconstructions in patients with a vessel-depleted neck but it should be limited to selected patients. This novel solution for situations where current techniques are unfeasible warrants further clinical research.

The Simultaneous Use of Breast Reduction and Internal Mammary Artery Perforator Flap in Sternal Wound Reconstruction.

Internal mammary artery perforator (IMAP)-based fasciocutaneous flaps have recently gained popularity in sternal wound reconstruction due to their decreased donor site morbidity. However, patients with significant macromastia or who are obese present a challenge when using these flaps due to their anatomy and associated comorbid conditions. Despite the prevalence of this population, there is a relative paucity of data on the use of local fasciocutaneous flaps and techniques to close sternotomy wounds in the obese population with hypertrophic or ptotic breasts. The authors describe a novel technique using simultaneous unilateral breast reduction with a fifth intercostal IMAP-based flap for closure of a median sternotomy wound through a case presentation, an anatomical injection study, and review of the literature. Five fresh female cadavers were used to conduct 8 trials of injection of the IMAP arteries, isolation of the fifth IMAP branch, and elevation of a local flap. The literature was comprehensively reviewed with a total of 33 cases of IMAP flaps for sternal reconstruction being described. The most commonly used perforators with the second and sixth IMAPs. Overall complication rate was reported to be 9.1% (3/33), with 2 cases reporting dehiscence and 1 with flap tip necrosis. No cases reported use of the fifth IMAP or formal breast reduction procedures, which was successfully performed in a 40-year-old diabetic female patient history of multiple left-sided thoracic surgeries and radiation with a chronic sternal wound.

A lateral costal artery complicating video-assisted thorascopic surgery (VATS) pleurectomy.

The lateral costal artery is a rare variant arising from the internal thoracic artery (ITA). It has been associated with steel syndrome after coronary artery bypass using the ITA as a conduit. Clinically, it is under-reported in the literature. We report the presence of a prominent lateral costal artery, coursing below the diaphragm, discovered during video-assisted thorascopic surgery pneumothorax surgery and preventing parietal pleurectomy.

Anatomical study of the internal thoracic arteries; implications for use in coronary artery bypass graft surgery.

PURPOSE: The feasibility of coronary artery bypass grafting using an internal thoracic artery (ITA) depends on the length of the graft with respect to the optimal route to reach the coronary target. The goal of this study was to assess the gain in length afforded by skeletonization and to evaluate the lengths of different pathways of the ITAs to the left coronary arteries. METHODS: The left and right ITAs were dissected out from 20 specimens and measured before and after skeletonization. Distance between the origin of the right ITA and the base of the left atrial appendage, corresponding to the proximal circumflex artery, was measured for both the transverse pericardial sinus and preaortic routes. RESULTS: Skeletonization gave a significant gain of length for both ITAs. Analysis showed no significant correlation between the ITA length and the height, weight, and BMI of specimens. We found no association between the length of the sternum and the length of skeletonized RITA or LITA. The anterior route of the skeletonized right ITA was shorter than the transverse pericardial sinus route in 18 cases. The average length to the circumflex artery territory was 132.8 ± 23.5 mm in front of the aorta and 150.5 ± 18.8 through the transverse pericardial sinus with a gain of length of 17.7 mm (p < 0.0001). CONCLUSION: Skeletonization gave significant gains in length of both ITAs. The preaortic route for the skeletonized right ITA toward the circumflex territory was shorter than the transverse pericardial sinus route in 90 % of cases.

Does patient sex affect the anatomic relationships between the sternoclavicular joint and posterior vascular structures?

BACKGROUND: Despite increased concern for injury during surgical reconstruction of the sternoclavicular joint, to our knowledge there are few studies detailing the vascular relationships adjacent to the joint. QUESTIONS/PURPOSES: We investigated sex differences in the following relationships for sternoclavicular joint reconstruction: (1) safe distance from the posterior surface of the medial clavicle's medial and lateral segments to the major vessels, (2) length of the first costal cartilage and safe distance from the first rib to the internal mammary artery, (3) minimum distance medial to the sternoclavicular joint for optimal hole placement, and (4) safe distance from the manubrium to the great vessels. METHODS: Fifty normal postcontrast CT scans of the chest were reviewed. Means, standard deviations, and 95% CI were calculated for each aforementioned measurement. A t-test was used to determine if a sex difference exists (p≤0.05). RESULTS: At the medial end of the clavicle, the safe distance from the medial segment (first 10 mm) to the major vessels was greater in males than in females (3.5 mm versus 2.4 mm, respectively; 95% CI, 3 mm-4 mm versus 1.7 mm-3 mm, respectively; p=0.014). For the lateral segment (next 10 mm), the distance also was safer in males than in females (3.3 mm versus 1.7 mm, respectively; 95% CI, 2.7 mm-4 mm versus 1.1 mm-2.3 mm, respectively; p<0.001). The mean length of the first costal cartilage also was greater in males (35.8 mm versus 30.1 mm, respectively; 95% CI, 33.8 mm-37.8 mm versus 28.5 mm-31.9 mm, respectively; p<0.001); the distance from the first costochondral joint to the internal mammary artery was safer in males than in females (19.1 mm versus 15.4 mm, respectively; 95% CI, 16.5 mm-21.8 mm versus 13 mm-17.9 mm, respectively; p=0.05). The minimum distance to avoid inadvertent penetration of the sternoclavicular joint was greater in males than in females (16 mm versus 12.3 mm, respectively; 95% CI, 14.6 mm-17.5 mm versus 11 mm-13.6 mm, respectively; p<0.001). The distance to vessels after penetration of the manubrium was not different between males and females (5.6 mm versus 3.9, respectively; 95% CI, 4.4 mm-6.8 mm versus 2.6 mm-5.2 mm, respectively; p=0.06). CONCLUSIONS: This study makes apparent the intimate relationships between vessels and the musculoskeletal structures associated with sternoclavicular reconstruction. Based on our findings, we recommend considering the sex of the patient, using caution when drilling, and protecting essential structures posterior to the joint.

A radioanatomic study of the internal mammary artery and its perforators using multidetector computed tomography angiography.

The Internal Mammary Artery (IMA) and its perforators play an important role in coronary bypass grafting and reconstructive breast, head, and neck surgery. This study aimed to obtain anatomic data pertaining to these vessels using Multi Detector Computed Tomography Angiography (MDCTA) and to demonstrate that the MDCTA could be a considerable assessment tool prior to surgery. In 50 outpatients (27 males and 23 females), the above-mentioned arteries were bilaterally evaluated with a 16-detector spiral computed tomography scanner. Based on the obtained images, diameters of the bilateral IMAs were separately measured in each intercostal spaces from 1 to 5 through their traces. IMAPs greater than 0.5 mm in diameter were bilaterally evaluated in terms of distance from the sternal border to the ramification point under the muscular layer, maximal external diameter at ramification from the IMA, and the length between the ramification point from the IMA and enter point to the subcutaneous fat tissue. Mean diameters of the left and right IMAs were 2.05 ± 0.50 mm and 2.20 ± 0.57 mm, respectively. Mean diameters, distances, and lengths of the perforators were 1.30 ± 0.30 mm, 6.80 ± 3.40 mm, 17.05 ± 6.07 mm on the left side and 1.32 ± 0.25 mm, 6.71 ± 3.43 mm, 17.35 ± 3.48 mm on the right side, respectively. No statistically difference was found between the sides (P > 0.05). About 20 of 36 perforators appeared in the second intercostal space, whereas there were eight in the first and eight in the third intercostal space. MDCTA, as a non-invasive vascular imaging method, can be a valuable tool for investigating the anatomic characteristics of the IMA and its perforators before planning an operation.

Is there a need for preoperative imaging of the internal mammary recipient site for autologous breast reconstruction?

Preoperative imaging of recipient-site vasculatur in autologous breast reconstruction may potentiate improved outcomes through the identification of individual variations in vascular architecture. There are a range of both normal and pathologic states which can substantially affect the internal mammary vessels in particular, and the identification of these preoperatively may significantly affect operative approach. There are a range of imaging modalities available, with ultrasound particularly useful, and computed tomography angiography (CTA) evolving as a useful option, albeit with radiation exposure. The benefits of CTA must be balanced against its risks, which include contrast nephrotoxicity and allergic reactions, and radiation exposure. The radiation risk with thoracic imaging is substantially higher than that for donor sites, such as the abdominal wall, with reasons including exposure of the contralateral breast to radiation (with a risk of contralateral breast cancer in this population 2 to 6 times higher than that of primary breast cancer, reaching a 20-year incidence of 15%), as well as proximity to the thyroid gland. Current evidence suggests that although many cases may not warrant such imaging because of risk, the benefits of preoperative CTA in selected patients may outweigh the risks of exposure, prompting an individualized approach.

Common trunk of left internal thoracic artery and thyrocervical trunk arising from the ipsilateral vertebral artery.

The sites of origin of the branches of the subclavian artery depict numerous anatomical variations. However, a common trunk of the internal thoracic artery (ITA) and thycocervical trunk (TCT) arising from the vertebral artery is a rare anatomical finding. Herein, we present the first case in which the common trunk of the left ITA and TCT arose from the ipsilateral proximal vertebral artery as discovered on pre-therapeutic evaluation by multidetector-row computed tomography and clearly confirmed by selective angiography. It is important to recognize such anatomic variations for surgical, diagnostic, and interventional radiologic procedures in the head, neck, thorax, and abdomen.

A rare cadaveric finding of ectopic origin of a bronchial artery: surgical and imaging consequences.

Bronchial arteries arise normally directly from the descending thoracic aorta, at the level between the fourth and sixth thoracic vertebra. However the anatomical variations are very frequent regarding the origin or the number of branches. We present a rare cadaveric finding of an ectopic right bronchial artery originating from the right subclavian artery through common stem with the right internal thoracic artery and we discuss the clinical significance of this finding. A 72-year-old formalin-embalmed male cadaver was dissected during a routine anatomical course. The right bronchial artery originated from the right subclavian artery with a common stem with the right internal thoracic artery. Although ectopic origin of the right bronchial artery from the right internal thoracic artery is rare, recognition of this anatomical variation is important in bronchial embolization due to hemoptysis, in coronary bypass grafting and in lung transplantation.

Vascular anatomy of the breast and its implications in the breast-sharing reconstruction technique.

The most frequently described breast-sharing procedure consists in a pedicled technique where the transferred lower breast pole is based on the lower perforators of the internal mammary (IM) artery. The current article investigates the vascular supply of the breast and its surgical implications in breast-sharing reconstruction. Contrast-enhanced magnetic resonance images of 55 patients (110 breasts) were retrospectively examined. A total of 473 branches of the IM, lateral thoracic (LT) and anterior intercostal (AI) arteries with a diameter greater than 0.5 mm were traced throughout their course in the breast. Distinct connections between the vessels were equally recorded. Although any vessel could vascularise any quadrant in the individual patient, blood supply to the lower quadrants came fundamentally from the AI arteries (76.2% of all the perforators). Lower IM branches (4th-5th) were seen to reach both lower quadrants in only 6.4% of the breasts, whereas LT branches did in 15.5%. In 86.4% of the breasts, at least a distinct AI perforator was seen to perfuse both lower quadrants. Well-defined connections between the IM and the LT arteries were observed in 41.8% of the breasts, always at or above the nipple-areola level. Other connections were far less common. Our study strongly indicates that the breast-sharing technique based on 4th-5th contralateral branches of the IM or LT arteries is unreliable in most patients. Given the unpredictable vascularization pattern in the lower breast pole, a preoperative imaging study is mandatory when the use of the contralateral breast is considered. Due to its accuracy, availability, and anatomical reliability, contrast-enhanced magnetic resonance is the best technique in the preoperative evaluation of the breast-sharing reconstruction.

The anatomy and variations of the internal thoracic (internal mammary) artery and implications in autologous breast reconstruction: clinical anatomical study and literature review.

BACKGROUND: The internal thoracic (IT) vessels (otherwise known as the thoracica interna or internal mammary vessels) are widely used as recipient vessels in autologous breast reconstruction. Despite this, normal and pathological variations in IT artery architecture have been described, and these have the potential to complicate dissection and the selection of suitable vessels. METHODS: A clinical anatomical study of 240 IT arteries (120 patients) and review of the literature was undertaken. Participants comprised 120 female patients undergoing preoperative imaging of the IT artery prior to autologous breast reconstruction, 42 with computed tomographic angiography (CTA) and 78 with ultrasound. RESULTS: There was complete concordance between surgical and radiological findings. An IT artery was present in 100% of cases, with a duplicate IT artery in two cases (1% overall). The position of the IT artery was between two IT veins most frequently (71.5% of cases), and was lateral to the vein(s) least frequently (6%). There were large IT perforators from the first and second intercostal spaces in 87 and 91% of cases, respectively, with the incidence of such perforators reducing in the lower spaces. The literature highlighted a range of cadaveric and clinical cases in which there was absence of a patent IT artery, variant course or size, and variant relationship to the IT vein. CONCLUSION: A range of congenital, pathological and iatrogenic variants in IT artery anatomy have the potential to limit the use of the IT artery in autologous breast reconstruction. Preoperative imaging with ultrasound or CTA may provide a clear and accurate method of identifying these anatomical variations pre-operatively.

The Importance of Fifth Anterior Intercostal Vessels following Nipple-Sparing Mastectomy.

BACKGROUND: The authors describe the vascular anatomy of the fifth anterior intercostal artery perforator and its role for perfusion of the nipple-areola complex following nipple-sparing mastectomy. METHODS: Twenty fresh cadavers were injected with 20 cc of colored latex through the internal mammary artery. The catheter was placed at the level of the second intercostal space after removal of the rib. The fifth intercostal space was dissected under magnification to observe the origin and trajectory of the fifth anterior intercostal artery perforator. Six selective computed tomographic angiograms of the fifth intercostal artery perforator were performed. A clinical case of nipple-sparing mastectomy in a woman with mammary hypertrophy is provided to demonstrate the utility of preserving the fifth anterior intercostal artery perforator. RESULTS: The fifth anterior intercostal artery perforator was consistently observed in all the cases and confirmed by angiography. The perforator gives rise to several branches that traverse in all directions. The ascending branches of the fifth anterior intercostal artery perforator are directed toward the nipple-areola complex and course within the subcutaneous layer between the skin and the parenchyma. The fourth and fifth anterior intercostal artery perforators are independent of one another. CONCLUSION: The main ascending branch of the fifth anterior intercostal artery perforator reaches the nipple-areola complex by the subcutaneous tissue independently of the Würinger fascia.

A cadaver study of the vascular territories of dominant and nondominant internal mammary artery perforators.

The perfusion territory of the pedicled internal mammary artery perforator flap has been described, but the number of perforators to be included in the flap's pedicle is controversial. We studied the vascular territory of the dominant perforator and the contribution of additional nondominant perforators to it. Therefore, the dominant perforators in 9 fresh cadavers and the nondominant perforators in 4 of these, were injected with water-based ink. The dominant perforator vascularized a territory extending from the superior border of the clavicle to the xiphoid, and from midsternal to the anterior axial fold, with a mean craniocaudal length of 19.4 cm (range, 17.0-24.0) and a mean mediolateral width of 18.6 cm (range, 16.0-22.5). Additional injection of nondominant perforators did not lead to any substantial enlargement of this territory. One single dominant perforator vascularizes a large part of the hemithorax, allowing for various flap designs. Nondominant perforators do not have to be included in the vascular pedicle of the internal mammary artery perforator flap, which leads to less donor-site morbidity.

Incidence of the accessory internal thoracic artery and its safety area in the thoracic wall.

OBJECTIVE: To provide the incidence, origin, size and the safety area of the accessory internal thoracic artery (AITA) in the fourth intercostal space. MATERIAL AND METHOD: One hundred and thirty two thoracic cages were dissected and examined for the presence of AITA. The origin, course, diameter and location in the fourth intercostal space of detected AITA were investigated. RESULTS: AITA with diameter ranging from 0.6 to 3.05 (mean = 1.76 +/- 0.69) millimeters existed in 10 of 132 (7.58%) cadavers. They originated from the upper part of the internal thoracic artery, close and inferior to the subclavian artery (0-3 cm, mean = 2.4 +/- 0.78) and ran inferolaterally on the deep surface of the thoracic wall and ended in the second to the sixth intercostal spaces. Most of them ended in the fifth intercostal spaces (28.57%). The artery was present bilaterally in 4 cases (3.03%) and unilaterally in 6 cases (4.55%). Most of these arteries were located close to the midaxillary line (0-3 cm, mean = 1.73 +/- 1.18) in the fourth intercostal space which is endangered in several surgical procedures such as thoracoscopy. CONCLUSION: Even the incidence of AITA is low (7.57%) but when present, it is endangered in thoracic surgical procedures. The safety area of AITA for surgical procedures in the fourth intercostal space is at least 3 centimeters anterior to the midaxillary line.

Is Internal Mammary to the Anterior Descending Always the Best Option?

The left internal mammary artery (LIMA) is the gold standard conduit used to revascularize the left anterior descending artery and has consistently been shown to be associated with better survival, graft patency, and freedom from cardiac events compared with other used conduits. Evaluation of LIMA flow and anatomy is not routinely done by the interventional cardiologist while performing the left heart catheterization. We present a case where the LIMA was found to be the major blood supply to the left leg, which might have led to leg ischemia if the LIMA had been used as graft.

Internal mammary artery: the primary conduit for surgical revascularization.

Internal mammary artery, by far, is the gold standard and first conduit for surgical revascularization especially when it comes to bypassing a lesion in the left anterior descending coronary artery. Several factors behind using this artery have been established, including but not limited to, the anatomical location, the course and flow, the elastic nature of the artery as well as the physiological characteristics that make this conduit to yield excellent long-term patency rates. This review aims to thoroughly examine current literature and establish the facts behind using this conduit in our daily surgical revascularization practice.

Uncommon Anatomic Variation of Left Internal Mammary Artery: God-Created Y-Graft Conduit.

The left internal mammary artery is the most accepted and widely used conduit in coronary artery bypass grafting. This report presents a rare case of very early bifurcation of the left internal mammary artery at the level of the third intercostal space.