Intrathoracic Course Research Articles

P146 PERIPHERALLY INSERTED CENTRAL VENOUS CATHETER AND PERSISTENT LEFT SUPERIOR VENA CAVA: WHAT SHOULD WE KNOW?

Abstract Peripherally inserted central catheters (PICCs) are widely used medical devices to provide medium to long–term infusion treatment and therapy. PICC placement is contraindicated in cases of deep–vein thrombosis, end–stage renal disease or if deep venous access is compromised. Among the possible complications there are some related to the interventional procedure (e.g. accidental puncture of an arterial vessel, injury to peripheral nerves, misplacement, arrhythmias, haematoma) and others related to the post–implantation phase (e.g. thrombosis, infection, gas emboli, phlebitis). One of the possible intra–procedural complications is the occasional finding of a persistent left superior vena cava (PLSVC). PLSVC is an anatomical variant present in at least 0.5% of the general population and its occurrence during interventional procedures is not uncommon. Clinical case description An 82–year–old woman was admitted to our Institute following a diagnosis of herpetic encephalitis (HSV1). She had a history of hypothyroidism undergoing substitution treatment. Cause the poor peripheral venous patrimony and the need of infusion therapy with acyclovir, levetiracetam and ceftriaxone, the indication for PICC implantation was given. After antibiotic prophylaxis and sterile field preparation, the procedure was performed with ultrasound–guided Seldinger technique by puncturing the left basilic vein. A successive X–ray showed the PICC running unusually parallel to the right sternum (Fig. 1). The echoscopy with bubble test allowed to visualize the agitated saline solution in the right atrium. In view of the suspected venous abnormality, the PICC was removed and a single–lumen MiniMidline 4F of 11 cm length was placed in the right basilic vein (4 mm). A subsequent chest CT scan visualised the PLSVC and its intrathoracic course, the presence of the right superior vena cava was also observed (Fig. 2). The PLSVC is an anatomical variant encountered during interventional procedures involving peripherally inserted central venous catheters. It is important to recognise this variant to avoid possible procedural and/or post–procedural related surgical complications.

ETIOPATHOGENESIS OF VOCAL CORD PARESIS AND PALSY IN A TERTIARY CARE CENTRE- A PROSPECTIVE STUDY

The purpose of this study was to identify the patients with vocal cord paresis and palsy and to establish the etiology based on the study performed in a tertiary care centre. The study was done prospectively in the Department of ENT in Mahatma Gandhi Medical College & Hospital, Jaipur, for 1 year, from September 2020 to August 2021. 50 patients with vocal cord paresis and palsy were identied and examined by using exible or rigid laryngoscopy to make the etiological diagnosis. The etiology of vocal cord immobility was determined by history and complete head and neck examination. Patients in whom no cause was found, a CT scan from base of skull upto thorax was done before labelling them as idiopathic. Most patients presented with complaints of change in voice (92%). Other common presenting complaints included difculty in breathing, difculty in swallowing, vocal fatigue and cough. Unilateral vocal cord paralysis (88%) was more common than bilateral paralysis (12%), of which left (58%) was more commonly affected than right (42%) vocal cord because of longer intrathoracic course of left recurrent laryngeal nerve. The most common age group affected was 51–60 years (26%) followed by 61–70 years (18%). Males (60%) were affected more than females (40%) in a ratio of 3:2 and among the affected males 80% were known smokers. The most common cause of vocal cord paresis and palsy was found to be malignancy larynx (36%), followed by idiopathic (28%). Other causes included carcinoma of lung, thyroid and oesophagus, inammatory, traumatic, systemic diseases like Rheumatoid Arthritis and Hypertension leading to stroke. Identifying the exact etiopathogenesis of vocal cord paresis and palsy in patients has been a challenge and is very important in order to establish a proper diagnostic and treatment protocol for these patients.

Nerve at risk: anatomical variations of the left recurrent laryngeal nerve and implications for thoracic surgeons.

OBJECTIVES Recurrent laryngeal nerve (RLN) injury during thoracic surgery may result in life-threatening postoperative complications including recurrent aspiration and pneumonia. Anatomical details of the intrathoracic course are scarce. However, only an in-depth understanding of the anatomy will help reduce nerve injury. The aim of this study was to assess the anatomic variations of the intrathoracic left RLN.METHODSLeft-sided vagal nerves and RLN were dissected in 100 consecutive Caucasian cadavers during routine autopsy. Anatomical details were documented. Available demographic data were assessed for possible correlations.RESULTSAll nerves were identified during dissection. Variant courses were classified in 3 different groups according to the level at which the RLN separated from the vagal nerve: above the aortic arch, level with the aortic arch and below the aortic arch. We found 11% of RLN separating above the aortic arch and crossing the aortic arch at a considerable distance to the vagal nerve. In 48% of the RLN, the nerve split off when it was level with the aortic arch, and 41% of the RLN leave the vagal nerve in a perpendicular direction below the aortic arch. All nerves crossed the ligamentum arteriosum on the posterior side. No gender-specific differences were observed.CONCLUSIONSMediastinal lymph node dissection in left-sided lung cancer patients puts the RLN at risk. With more detailed anatomical knowledge about its course, it is possible to avoid risking the nerve. Visualization will help protect the nerve.

Higher Division of Right Internal Thoracic Artery – a case report

The internal thoracic artery (ITA) is the largest artery of the thoracic wall. ITA has become a conduit of choice for coronary artery bypass graft surgery because of its predictable intrathoracic course, anatomical proximity to the heart and excellent long-term patency. The rare and unexpected occurrence of anomalies of the internal thoracic artery such as the one reported here may complicate the entire procedure of revascularization of the myocardium. We conclude that knowledge of variation of internal thoracic artery is necessary during surgical procedures that involve thoracic region.DOI: http://dx.doi.org/10.3126/jbs.v2i1.13032Journal of Biomedical Sciences 2015 Mar.; 2(1): 7-9

Kontinuierliches Neuromonitoring des N. laryngeus recurrens in der offenen Schilddrüsenchirurgie

Intraoperative neuromonitoring allows the evaluation of the recurrent laryngeal nerve function only at the moment of stimulation. Continuous vagal stimulation checks the complete extra- and intrathoracic course of the recurrent laryngeal nerve during all phases of preparation. The continuously running neuromonitoring is not implemented in the practice of thyroid surgery so far. A newly developed vagal probe for continuous stimulation is introduced and tested in a series of 20 thyroid resections. This advancement in probe technique for intraoperative neuromonitoring allows safe and continuous verification of the recurrent laryngeal nerve function during surgical preparation and may be beneficial in anatomically difficult situations.

Bilateral internal thoracic artery harvesting; anatomical variations to be considered

Predictable intrathoracic course, anatomical proximity to heart and long-term patency has made Internal thoracic artery (ITA) a conduit of choice in coronary artery bypass grafting (CABG). Its frequent bilateral use has necessitated the need to have a comparative knowledge of surgical anatomy of ITA on both sides. A random study was conducted on 100 adult human cadavers. Sternocostal wall was removed and fixed in 10% formalin and dissected for detailed anatomy of ITA. All observations were expressed as mean ± 2SD and appropriate statistical analysis conducted. ITA originated in common trunk with other branches of subclavian artery in 12% on right side and 4% on left. Mean length of right ITA was 20.15 ± 1.22 cm, left 19.83 ± 1.66 cm in 28% of cases where bilateral ITA terminated in 6th Intercostal space (ICS). On pattern of origin of sternal branches from ITA 3 groups were observed. Group-I-some sternal branches arising from common trunk of ITA on both sides (24%), Group-II-some sternal branches arising from common branch of ITA on one side only (54%), Group-III-all sternal branches arising directly from ITA on both sides (22%). Phrenic nerve crossed anterior to ITA on both sides in 52%, posteriorly in 14% and in remaining it crossed anteriorly on one side and posteriorly on other. Variations as described in our study in relations to phrenic nerve, level of bifurcation and sternal blood supply must be kept in mind while harvesting bilateral ITA to reduce risk of sternal dehiscence by preserving the sternal blood supply from common trunk and to prevent post operative phrenic nerve palsy.

Extended TRAM flap: feasibility study on fresh human cadavers.

The purpose of this study was to investigate the feasibility of a superiorly based TRAM flap for breast reconstruction with its superior border abutting the inframammary fold. This flap would have a primary blood supply from the superior epigastric vessels, similar to a free flap attached to the mammary system. This flap, however, would not require microsurgery. Instead, it would have its superior epigastric pedicle lengthened by partial rib resection. Donor site closure would be accomplished by reverse abdominoplasty and the donor scar hidden in the inframammary fold. The surgical anatomy of such an extended TRAM flap (eTRAM) was investigated by cannulation of the internal mammary artery (IMA) in 10 fresh human cadavers bilaterally, injection with latex, and then dissection throughout its intrathoracic course. At the level of the third intercostal space, the mean external diameters of the right and left IMA were found to be 2.5 mm and 2.3 mm, respectively. The diameter of the vessel decreased until the IMA bifurcated into the superior epigastric artery and the musculophrenic artery, usually at the sixth intercostal space. The superior epigastric artery, having a mean diameter of 1.6 mm at its origin, descended caudally behind the seventh costal cartilage and could be followed until it entered the posterior rectus sheath and the rectus abdominis muscle. On its downward course, it was not embedded in the diaphragm muscle and was easily separated without violation of the thoracic cavity. From this anatomic study, it seems to be possible to raise an eTRAM after partial rib resection. Some technical considerations of such a flap are discussed. This modification of the TRAM would be helpful to surgeons commonly performing pedicled TRAM flaps and might extend its applicability beyond breast reconstruction to chest wall, intrathoracic, and head and neck reconstruction.

Three-dimensional time-of-flight MR angiography of the arch of aorta and its major branches: A comparative study with contrast angiography

The region of the arch of aorta and the intrathoracic course of its major branches was evaluated in 11 patients using three-dimensional time-of-flight magnetic resonance (MR) angiography. Abnormalities such as stenosis, occlusion, dilatation and aneurysm formation were documented in the innominate, both common carotid and both subclavian arteries. The results were compared with those of contrast angiography. There was a good correlation in 47 of the 55 arteries compared. There were five false positive results including overestimation of a stenosis, and three false negative results including underestimation of a stenosis. MR angiography had a sensitivity of 93% and a specificity of 89% for correctly detecting or excluding an abnormality. These results suggest that three-dimensional time-of-flight MR angiography demonstrates lesions in the major branches of the arch of aorta fairly accurately and will prove useful in the initial evaluation and in follow up studies.

Tumours involving the intrathoracic vagus and phrenic nerves demonstrated by computed tomography: Anatomical features

Four cases of mediastinal tumours involving the intrathoracic vagus and phrenic nerves are presented and their computed tomographic (CT) features are described with particular attention to the intrathoracic course of these nerves. One case of mediastinal plexiform neurofibromatosis appeared as a series of low attenuation masses along the intrathoracic course of the nerves. Three examples of neurilemmomas of the vagus nerve appeared as masses with central low attenuation; one in the retrocaval area, one to the left of the aortic arch, and one in the right paraoesophageal area. Familiarity with the CT anatomy of the vagus and phrenic nerves will greatly assist in the diagnosis of mediastinal tumours.

Déafférentation vagale totale et évacuation gastrique chez le porc

50-kg pigs fed a purified wheat starch and casein diet were fitted with a gastric cannula. Gastric emptying was studied by checking the residual gastric contents at 30 min and 1, 2, 4 and 7 hrs after feeding. Five of the 25 pigs were used as controls; 5 were submitted to total vagal deafferentation including removal of the left nodose ganglion, right truncal vagotomy at the diaphragm and resection of the interconnecting branches between the two vagi on their intrathoracic course; 5 were submitted to total contralateral vagal deafferentation; 5 only underwent left truncal vagotomy and resection of the connectives; 5 were submitted to the contralateral operation. Total vagal deafferentation, suppressing bilateral afferences originating below the diaphragm, resulted in much higher residual gastric contents at all times studied after the meal. Significant gastric retention was also observed after unilateral truncal vagotomy as compared to the controls. Nevertheless, this retention was significantly lower than after total deafferentation. The reduced emptying rate after total vagal deafferentation was a result of the loss of all afferences, while the simultaneous reduction of efferences was of little importance. The mechanisms responsible for gastric retention have been discussed in relation with the sustained antral hyperactivity previously found in deafferented pigs and with the various controls of gastric emptying. Several factors may be involved, including both motor and secretory changes. The prolonged postprandial activity of the gastric antrum seemed to be a consequence of gastric retention.