Variations of coronary sinus tributaries among patients undergoing cardiac resynchronisation therapy.

BACKGROUND: In cardiac resynchronisation therapy (CRT), the coronary venous system is used for left ventricular pacing electrode placement. Despite the well- -known anatomy of the coronary sinus and its tributaries, heart failure patients' remodelled and enlarged left ventricles may impede the successful lead placement because of acquired anatomical obstacles. MATERIALS AND METHODS: Fifty-five patients qualified for CRT treatment were divided into ischaemic and non-ischaemic cardiomyopathy. Forty-four control groups without heart failure underwent dual-source computed tomography (CT). Rendered reconstructions of cardiac coronary systems were compared. RESULTS: The presence of main tributaries was comparable in all groups. The left marginal vein, small cardiac vein, and oblique vein of the left atrium were present in 63%, 60%, and 51% of the hearts in all the groups. CRT referred CTs had significantly longer distances between posterior and lateral cardiac veins over the left ventricle (p < 0.05), wider angles of tributaries (p = 0.03), and smaller lumen of coronary sinus (p = 0.03). In the non-ischaemic group, the posterior interventricular and great cardiac veins are more extensive than in the control group. Age-related analysis of vessel size shows a moderate correlation between age and diminishing mean vessel size in all the groups studied. CONCLUSIONS: The general structure of the coronary heart system is consistent in patients with and without heart failure. The variance of the general structure, or the presence of adequate veins, is an individual variation. The use of CT and analysis of the coronary veins allow better planning of the CRT-D implantation procedure and may reduce the risk of ineffective left ventricular electrode implantation.

Ultrasound-guided topographic anatomy of the medial calcaneal branches of the tibial nerve.

BACKGROUND: The purpose of this study was to evaluate the topographic anatomy of the tibial nerve and its medial calcaneal branches in relation to the tip of the medial malleolus and to the posterior superior tip of the calcaneal tuberosity using the ultrasound examination and to verify its preoperative usefulness in surgical treatment. MATERIALS AND METHODS: Bilateral ultrasound examination was performed on 30 volunteers and the location of the tibial nerve bifurcation and medial calcaneal branches origin were measured. Medial calcaneal branches were analysed in reference to the amount and their respective nerves of origin. RESULTS: In 77% of cases, tibial nerve bifurcation occurred below the tip of the medial malleolus with the average distance of 5.9 mm and in 48% of cases above the posterior superior tip of the calcaneal tuberosity with the average distance of 2.7 mm. In 73% of cases medial calcaneal branches occurred as a single branch originating from the tibial nerve (60%). The average distance of the first, second and third medial calcaneal branch was accordingly 9.3 mm above, 9.5 mm below and 11.6 mm below the tip of the medial malleolus and 17.7 mm above, 1.6 mm below and 4 mm below the posterior superior tip of the calcaneal tuberosity. CONCLUSIONS: As the tibial nerve and its branches present a huge variability in the medial ankle area, in order to prevent the iatrogenic injuries, the preoperative or intraoperative ultrasound assessment (sonosurgery) of its localisation should be introduced into the clinic.

The terminal branch of the posterior interosseous nerve: an anatomic and histologic study.

BACKGROUND: The aim of this study was to evaluate the terminal branch of the posterior interosseous nerve (PIN) by anatomically and histologically assessing the number, dimension, and area of its individual fascicles, by determining the dimension and area of the whole nerve itself, and by calculating the nerve density ratio (ratio of the sum of the areas of individual fascicles to the area of the whole nerve) of the terminal branch of the PIN. MATERIALS AND METHODS: Twenty-eight terminal branches of the PIN nerve samples were collected from patients undergoing partial denervation of the wrist. The nerve samples were fixed in 10% buffered formalin and stained with haematoxylin and eosin to visualise their nerve bundles. Quantitative analysis of individual fascicles and the whole nerve itself were carried out. RESULTS: Ten nerve samples (35.7%) had one single fascicle (group 1) while the remaining 18 nerve samples (64.3%) contained 2-9 fascicles (group 2). The difference in the sum of the areas of individual fascicles between the two groups did not constitute a statistical difference. Statistically significant between-group differences (p < 0.05) were seen in the area of whole nerve, the ratio of fascicle area to the nerve cross-sectional area and the cross-section maximum nerve length and width. CONCLUSIONS: The number of nerve fascicles in the terminal branch of the PIN does not affect the overall size of the nerve. The majority of the volume of multi-fascicle nerves, therefore, primarily consists of the internal perineurium. However, due to the low number of nerves, this question cannot be clearly answered. This sets a further direction for further research on a larger group.

Assessing the innervation of the dorsal wrist capsule using modified Sihler's staining.

BACKGROUND: The aim of this study was to assess the innervation of the dorsal articular capsule of the wrist using modified Sihler's staining. MATERIALS AND METHODS: Thirty dorsal wrist capsules were collected from 15 donors (both sides) within 12 hours of death. All the capsules were collected in the same manner - using the dorsal incision. The specimens were stained according to the protocol of the modified Sihler's staining technique. The preserved capsules were analysed under 8-16× magnification of an optical microscope for the presence of major nerve trunks, their major and minor branches, and nerve connections. RESULTS: The range of innervation visualised was that the posterior interosseous nerve innervated approximately 60% of the central part; the remaining area was innervated by the dorsal sensory branch of the radial nerve and medial antebrachial cutaneous nerve. The constant findings were the branches departing from the ulnar side of the posterior interosseous nerve and from the radial side, with an exception seen in 2 cases. A communicans branch between the posterior interosseous nerve and medial antebrachial cutaneous nerve was seen in all the specimens. The posterior interosseous nerve innervation extended beyond the level of the carpometacarpal joints II-V. CONCLUSIONS: The modified Sihler's staining technique allows for transparent visibility of the nerves that innervate the dorsal wrist capsule. However, it does not allow as accurate assessment as does histological examination, especially regarding the evaluation of nerve endings. Nevertheless, this method provides a significantly larger area of nerve observation than is provided by histological examination.

An anatomical investigation of rare upper limb neuropathies due to the Struthers' ligament or arcade: a meta-analysis.

BACKGROUND: The Struthers' ligament (SL) is a fibrous band that originates fromthe supracondylar humeral process and inserts into the medial humeral epicondyle, potentially compressing both the median nerve and brachial artery. The controversial Struthers' arcade (SA) is a musculotendinous band found in the distal end of the arm that might compress the ulnar nerve. This study aimed to evaluate the pooled prevalence estimate of the SL and SA, and their anatomical features. MATERIALS AND METHODS: A meticulous search of major electronic medical databases was carried out regarding both structures. Applicable articles (and all relevant references) were analysed. Data from the eligible articles was extracted and evaluated. The quality and the potential risk of bias in the included studies were assessed using the AQUA tool. RESULTS: The arcade was reported in 13 studies (510 arms), whereas the ligament in 6 studies (513 arms). The overall pooled prevalence estimate of the ligament was 1.8%, and 52.6% for the arcade. Most frequently, the ulnar nerve was covered by a tendinous arcade (42.2%). In all cases, the ligament inserted into the medial humeral epicondyle, but had various origins. Only 1 study reported compression of the median nerve by the ligament, whilst another contradicted this view. CONCLUSIONS: Although the SL is rare, and the SA is a valid anatomical entity (though with a variable presentation), clinically meaningful neurovascular entrapments caused by these structures are infrequent. Nonetheless, a better understanding of each may be beneficial for the best patient outcomes.

The anatomical landmarks effective in the localisation of the median nerve during orthopaedic procedures.

BACKGROUND: The aim of this study was to create a safe zone for surgeons who perform procedures in the wrist to avoid iatrogenic damage to the median nerve (MN) by identifying anatomical landmarks using ultrasound (USG). MATERIALS AND METHODS: We measured the distances between the MN and two easily identifiable anatomical landmarks at the level of the proximal border of carpal ligament using USG. RESULTS: A total of 57 volunteers (n = 114 upper limbs) were included in this study. Our main findings revealed that the distance from the flexor carpi radialis tendon to MN (FCR-MN) was 7.87 mm (95% confidence interval 7.37-8.37) and the distance from flexor carpi ulnaris tendon to MN (FCU-MN) was 19.09 mm (95% confidence interval 18.51-19.67). CONCLUSIONS: The tendons of FCR and FCU are easily identifiable landmarks that can be distinguished using simple palpation. Based on our USG findings, the area around FCR should be carefully navigated to avoid iatrogenic injury to the MN during surgical procedures around the carpal tunnel.

Computer-assisted measurements of the histological structure of the tibial nerve and its terminal branches.

BACKGROUND: The aim of this study was to analyse the histological structure (cross-sectional area [CSA] and number of nerve bundles) of the distal part of the tibial nerve and its terminal branches (medial plantar nerve, lateral plantar nerve) using computer-assisted image analysis. MATERIALS AND METHODS: The tibial nerve and its distal branches (medial and lateral plantar nerves) were dissected from the fresh cadavers. Each nerve was harvested 5 mm proximally and respectively 5 mm distally from the tibial nerve bifurcation, marked, dehydrated, embedded in paraffin, sectioned at 2 µm slices and stained with haematoxylin and eosin. Then photographed and analysed using Olympus cellSens software. RESULTS: The studied group comprised 28 female and 32 male feet (mean age 68.1 ± 15.2 years). The mean CSA and the number of nerve bundles were respectively 17.86 ± 4.57 mm2, 33.88 ± 6.31 for the tibial nerve, 9.58 ± 1.95 mm2, 23.41 ± 7.37 for the medial plantar nerve and 7.17 ± 2.36 mm2, 15.06 ± 5.81 for the lateral plantar nerve in males and 12.27 ± 2.45 mm2, 26.32 ± 8.87 for the tibial nerve, 7.81 ± 1.41 mm2, 17.71 ± 5.28 for the medial plantar nerve and 5.83 ± 1.25 mm2, 11.50 ± 3.72 for the lateral plantar nerve in females. Both CSA and number of nerve bundles of the tibial, medial plantar and lateral plantar nerves revealed no statistical differences when comparing foot side of the individual. The statistical difference was related to the gender, showing significantly bigger CSA and number of nerve bundles in males (CSA: p = 0.000, p = 0.000, p = 0.016; number of nerve bundles: p = 0.01, p = 0.003, p = 0.004, respectively). A positive correlation was found between the donor age and the tibial nerve CSA (r = 0.44, p = 0.000). A significant statistical difference was found between the medial and lateral plantar nerves both in CSA and number of nerve bundles (p < 0.001, p < 0.001, respectively). CONCLUSIONS: The CSA and the number of nerve bundles in the distal part of the tibial nerve and its branches are significantly larger in males with no differences between right and left foot of the individual. The tibial nerve shows increasing CSA with advanced age. The medial plantar nerve has larger CSA and more nerve bundles than the lateral plantar nerve.

Comparison of the histological structure of the tibial nerve and its terminal branches in the fresh and fresh-frozen cadavers.

BACKGROUND: The aim of this study was to compare the histological structure (cross-sectional area [CSA] and number of nerve fascicles) of the distal part of the tibial nerve (TN) and its terminal branches (medial plantar nerve [MPN], lateral plantar nerve [LPN]) in the fresh and fresh-frozen cadavers using computer assisted image analysis. MATERIALS AND METHODS: The TNs with terminal branches (MPN and LPN) were dissected from the fresh and fresh-frozen cadavers. Each nerve was harvested 5 mm proximally and respectively 5 mm distally from the TN bifurcation, marked, dehydrated, embedded in paraffin, sectioned at 2 µm slices and stained with haematoxylin and eosin. Then the specimens were photographed and analysed using Olympus cellSens software. RESULTS: The fresh cadavers' group comprised 60 feet (mean age 68.1 ± 15.2 years). The mean CSA and the number of nerve fascicles were respectively 15.25 ± 4.6 mm2, 30.35 ± 8.45 for the TN, 8.76 ± 1.93 mm2, 20.75 ± 7.04 for the MPN and 6.54 ± 2.02 mm2, 13.40 ± 5.22 for the LPN. The fresh-frozen cadavers' group comprised 21 feet (mean age 75.1 ± 9.0 years). The mean CSA and the number of nerve fascicles were respectively 13.71 ± 5.66 mm2, 28.57 ± 8.00 for the TN, 7.55 ± 3.25 mm2, 18.00 ± 6.72 for the MPN and 4.29 ± 1.93 mm2, 11.33 ± 1.93 for the LPN. Only LPNs showed statistical differences in the CSA and the number of nerve fascicles between examined groups (p = 0.000, p = 0.037, respectively). A positive correlation was found between donors age and tibial nerve CSA in the fresh cadavers group (r = 0.44, p = 0.000). A statistical difference was found between the MPN and LPN both in the CSA and the number of nerve fascicles (p < 0.001, p < 0.001, respectively). CONCLUSIONS: The CSA and the number of nerve fascicles of the tibial and medial plantar nerves were similar in the fresh and fresh-frozen cadavers whilst different in the LPN. The TN showed increasing CSA with the advanced age in the fresh cadavers. The MPN had larger CSA and more nerve fascicles than the LPN.

Computer-assisted assessment of the histological structure of the human sural nerve.

BACKGROUND: The aim of this study was to assess the histological structure (cross-sectional area - CSA, number of nerve bundles) of the human sural nerve at the level above the lateral malleolus, using computer-assisted image analysis. MATERIALS AND METHODS: This study has been conducted using sural nerves dissected from cadavers during routine autopsies. The harvested tissues samples were dehydrated, embedded in paraffin, sectioned at 4 µm and stained with haematoxylin and eosin. Each cross-section was photographed (16 × magnification) and the images were analysed using Java ImageJ. RESULTS: The studied group comprised 12 women and 25 men (mean age 60.1 ± 15.7 years), yielding a total of 74 sural nerves (37 right vs. 37 left). The mean ± standard deviation CSA of the sural nerve was 0.14 ± 0.07 cm2. The mean number of nerve bundles in the sural nerve was 10.5 ± 6.0. In terms of gender and side, neither the CSA (p = 0.45 and p = 0.79, respectively) nor the number of nerve bundles revealed any differences (p = 0.34 and p = 0.47, respectively). Strong negative correlations were noted between the age of the donors and the sural nerve CSA (r = -0.69,p = 0.02), as well as the number of nerve bundles (r = -0.57, p = 0.06). CONCLUSIONS: This study shows that there are no statistical differences between the CSA and the number of nerve bundles in the sural nerve when compared by gender and side of the lower limb. This study also allows drawing the conclusion that the sural nerve degenerates with age in terms of both the CSA and the number of nerve bundles.

'Venous lakes' - a corrosion cast scanning electron microscopy study of regular and myomatous human uterine blood vessels.

BACKGROUND: The aim of this study was to evaluate the venous structure of regularand myomatous human uteri, using corrosion casting and scanning electron microscopy (SEM). Special attention was paid to the endometrium and the socalled 'venous lakes'. MATERIALS AND METHODS: Uteri collected at autopsy (n = 67) were injected with Mercox CL-2R resin, which penetrated the capillary bed and filled both arteriesand veins. After the polymerisation of the resin, the corrosion was performed. The obtained vascular casts, visualising all vessels including capillaries, were examinedusing scanning electron microscopy. RESULTS: Amongst the 67 uteri prepared for the corrosion casting, only 22 (15 containing leiomyomata) yielded casts of acceptable quality for SEM assessment. Veins of the endometrium and the myometrium were present in the form of a chaotic network, which did not run parallel to the arterialsystem, but was rather independent. Microscopic venous dilations ('venouslakes') were observed both within the functional layer of the endometrium and the myometrium. They were digit-like in shape and could be compared to venous sinuses. They drained the subendothelial capillary plexus and were supplied by numerous capillaries and venules. Their size ranged from 270 to 420 µm. Those dilatations were absent in the outer myometrium and the perimetrium, as well as the uterine cervix. We have not observed any arteriovenous anastomoses. CONCLUSIONS: The myomatous uteri tend to have larger venous lakes than the normal uteri. The number and size of venous lakes increases with menstrual cycle progression. Further data on morphology and changes in venous lakesusing scanning electronic microscopy should be acquired.

Vascular architecture of the human uterine cervix, as assessed in light- and scanning electron microscopy.

BACKGROUND: The aim of this study was to visualise and describe the vasculature of the human uterine cervix. MATERIAL AND METHODS: The material for this study was obtained from women (age between 20 to 45 years) during autopsy. The material was collected not later than 24 h post-mortem. This study was performed using uteri from cadavers of menstruating nulliparas (33 uteri) and menstruating multiparas (27 uteri). Collected uteri were perfused via the afferent vessels with Mercox resin (for corrosion-casting and SEM assessment) or acrylic paint solution (light microscopy assessment). The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/121/8/2007). RESULTS: In all cases bilateral cervical branches (1-4), originating from the uterine artery, were found. Both in the vaginal and supravaginal parts of the cervix, four distinct vascular zones were found. In the pericanalar zone ran small veins, responsible for draining the mucosal capillaries. Both in the muscular layer, as well as in the pericanalar zone, arterioles, and venules passed close to each other, often adjoining. CONCLUSIONS: This study does not confirm the existence of a single cervicovaginal artery, but shows that the vascular supply of the cervix comes from several vessels. It also introduces the idea of two systems, responsible for draining blood from the mucosal capillaries. Neither assessment in light microscopy nor in SEM revealed any differences between multiparas and nulliparas, regarding the vascular architecture of the cervix.

Median nerve thenar motor branch anatomical variations.

BACKGROUND: The aim of this study was to determine the prevalence of the different types of median nerve thenar motor branch and to compare them with literature data. MATERIAL AND METHODS: This study was conducted using median nerves dissected from cadavers stored in a 10% solution of formaldehyde at the Department of Anatomy of Jagiellonian University Medical College (JUMC) and cadavers from the Department of Forensic Medicine JUMC. The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/ /209/B/2002). RESULTS: The studied group comprised 8 (26.7%) women and 22 men (age between 23 and 92 years), yielding a total of 60 thenar motor branches (30 right vs. 30 left). Forty-seven (78.3%) nerves were classified as extraligamentous, 12 (20%) were subligamentous, and 1 (1.7%) was transligamentous. As for the side of origin of the thenar motor branch, in 45 (75%) cases it was the radial side and in 2 (3.33%) cases it was the ulnar side. CONCLUSIONS: The obtained results confirm that the extraligamentous type of thenar motor branch is the most common and that the ulnar origin of the thenar motor branch is the rarest.

The use of computer-assisted image analysis in measuring the histological structure of the human median nerve.

BACKGROUND AND AIM: The aim of this study was to assess the histological structure of the median nerve and its motor branch (number and arrangement of nerve bundles) and the cross-sectional area (CSA) of the median nerve (on the level of the carpal tunnel). MATERIAL AND METHODS: This study has been conducted using median nerves dissected from cadavers stored in a 10% solution of formaldehyde at the Department of Anatomy of the Jagiellonian University Medical College and cadavers from the Department of Forensic Medicine of the Jagiellonian University Medical College. After dissection the median nerves were stained with haematoxylin and eosin and histological slides were prepared. These were later photographed (16 x magnification) and analysed using ImageJ software. The research protocol was approved by the Jagiellonian University Ethics Committee (registry KBET/209/B/2002). RESULTS: The studied group comprised 8 women and 22 men (age between 23-92 years), yielding a total of 60 median nerves (30 right vs. 30 left). In 4 (6.67%) cases an accessory motor branch was found. The mean CSA of the median nerve was 0.19 cm(2). The median nerves from the right hand had a statistically larger CSA (p = 0.017). The number of nerve bundles in the median nerve varied between 13 to 38 and in the motor branch of the median nerve between 4 to 14. CONCLUSIONS: The nerve bundles of the median nerve, at the level of the carpal tunnel, display no particular type of arrangement. ImageJ software proved useful in the assessment of the histological structure of the human median nerve and its motor branch.

The median nerve in the carpal tunnel.

A study of the variations of the course and branching pattern of the median nerve within the carpal tunnel were carried out on 60 wrists from 30 fresh cadavers autopsied in the Department of Forensic Medicine of Jagiellonian University Medical College. The results were compared with the literature. The study confirmed that the extraligamentous type of motor branch variation is most common. The transligamentous course of the nerve is of special importance: it is usually accompanied by hypertrophic muscle, and the nerve hidden within this muscle can easily be cut during transection of the retinaculum. The results proved the necessity of approaching the median nerve from the ulnar side when opening the carpal tunnel.

An anomalous bilateral muscle in Guyon's canal found during cadaver study.

During anatomical dissection, an unusual bilateral muscle in the region of Guyon's canal was found in a 29-year-old human male cadaver. It originated from the pisiform bone and inserted to the flexor retinaculum. The muscle passed between the superficial and deep branch of the ulnar nerve. The ulnar artery passed anteriorly to the muscle. This work reports this finding and tries to categorize it in one of the groups following the literature.