Posterior Cervical Keyhole Laminoforaminotomy: A Cadaveric Comparative Study to Evaluate Limits of Bony Resection

2018 ◽  
Vol 16 (5) ◽  
pp. 607-613 ◽  
Author(s):  
Ahmed B Bayoumi ◽  
Selim Berk ◽  
Ibrahim E Efe ◽  
Elif Gulsah Bas ◽  
Melissa Duran ◽  
...  
Keyword(s):  
Comparative Study ◽  
Surface Area ◽  
Nerve Root ◽  
Root Length ◽  
Maximal Length ◽  
Nerve Roots ◽  
Surface Areas ◽  
Lateral Portion ◽  
The Right ◽  
Cervical Roots

Abstract BACKGROUND The posterior cervical keyhole (KH) laminoforaminotomy has been described to involve the lateral portion of cervical laminae of the upper vertebra alone (small KH) or of both upper and lower vertebrae (large KH). OBJECTIVE To microscopically compare the two keyhole techniques in terms of their ability to expose the corresponding cervical roots. METHODS Ten cadaveric specimens were operated bilaterally from C3-4 to C6-7 level to expose a total of 80 nerve roots. The large KH was applied to the left side, the small KH to the right side. The maximal length of exposed nerve roots was measured under microscope. The virtual optimal KH surface area was determined using digital software. Each root was inspected for exposure of its root and axilla. RESULTS The maximal exposed nerve root length on the large KH side was significantly larger than on the small KH side at C3-4, C5-6, and C6-7 levels (P = .031, P = .002, P = .003). No significance was reported for C4-5 (P = .06). We could expose right axillae in (3/40) and left axillae in (33/40; P < .001). Optimal keyhole surface areas were 37.9, 38.2, 38.7, and 46.2 mm2 in craniocaudal order. CONCLUSION Large KH defects involving both upper and lower laminae and facets can expose the roots to greater extent than small KH defects at C3-4, C5-6, and C6-7 levels. Large KH defects may allow better exposure of nerve roots axillae than small KH defects.

Neurovascular structures adjacent to the lumbar intervertebral discs: an anatomical study of their morphometry and relationships

2011 ◽  
Vol 14 (5) ◽  
pp. 630-638 ◽  
Author(s):  
Mehmet Arslan ◽  
Ayhan Cömert ◽  
Halil İbrahim Açar ◽  
Mevci Özdemir ◽  
Alaittin Elhan ◽  
...  
Keyword(s):  
Nerve Root ◽  
Lumbar Disc ◽  
Anatomical Study ◽  
Intervertebral Discs ◽  
Nerve Roots ◽  
Disc Space ◽  
Anatomical Knowledge ◽  
The Mean ◽  
The Right ◽  
Neurovascular Structures

Object Although infrequent, injury to adjacent neurovascular structures during posterior approaches to lumbar intervertebral discs can occur. A detailed anatomical knowledge of relationships may decrease surgical complications. Methods Ten formalin-fixed male cadavers were used for this study. Posterior exposure of the lumbar thecal sac, nerve roots, pedicles, and intervertebral discs was performed. To identify retroperitoneal structures at risk during posterior lumbar discectomy, a transabdominal retroperitoneal approach was performed, and observations were made. The distances between the posterior and anterior edges of the lumbar intervertebral discs were measured, and the relationships between the disc space, pedicle, and nerve root were evaluated. Results For right and left sides, the mean distance from the inferior pedicle to the disc gradually increased from L1–2 to L4–5 (range 2.7–3.8 mm and 2.9–4.5 mm for right and left side, respectively) and slightly decreased at L5–S1. For right and left sides, the mean distance from the superior pedicle to the disc was more or less the same for all disc spaces (range 9.3–11.6 mm and 8.2–10.5 mm for right and left, respectively). The right and left mean disc-to-root distance for the L3–4 to L5–S1 levels ranged from 8.3 to 22.1 mm and 7.2 to 20.6 mm, respectively. The root origin gradually increased from L-1 to L-5. The right and left nerve root–to-disc angle gradually decreased from L-3 to S-1 (range 105°–110.6° and 99°–108°). Disc heights gradually increased from L1–2 to L5–S1 (range 11.3–17.4 mm). The mean distance between the anterior and posterior borders of the intervertebral discs ranged from 39 to 46 mm for all levels. Conclusions To avoid neighboring neurovascular structures, instrumentation should not be inserted into the lumbar disc spaces more than 3 cm from their posterior edge. Accurate anatomical knowledge of the relationships of intervertebral discs to nerve roots is needed for spine surgeons.

scholarly journals Surgical placement of rectus sheath catheters in a cadaveric cystectomy model

2018 ◽  
Vol 100 (2) ◽  
pp. 120-124 ◽  
Author(s):  
ECP Chedgy ◽  
G Lowe ◽  
R Tang ◽  
C Krebs ◽  
A Sawka ◽  
...  
Keyword(s):  
Abdominal Surgery ◽  
Surface Area ◽  
Nerve Root ◽  
Rectus Sheath ◽  
Rectus Muscle ◽  
Midline Incision ◽  
Nerve Roots ◽  
The Mean ◽  
Peritoneal Spread ◽  
Nerve Root Involvement

Introduction Surgically inserted rectus sheath catheters (RSCs) are used increasingly for analgesia after cystectomy and other abdominal surgery. Currently, there is little information on the optimal positioning of RSCs to allow maximal spread of local anaesthetic. This study sought to assess the spread of dye injected via RSCs and to highlight the extent of its coverage in a fresh unembalmed cadaveric cystectomy model in order to confirm the nerve endings that are likely to be anaesthetised with RSCs. Methods Four cadavers underwent lower midline incision with limited bladder mobilisation. A RSC was inserted into the eight hemiabdomens. The RSCs were positioned either anterior (n=5) or posterior to the rectus muscle (n=3). Dye was injected down the RSCs to evaluate spread. The eight hemiabdomens were dissected anatomically to determine the surface area of dye spread and nerve root involvement. Results The mean surface area of dye spread with anteriorly placed RSCs was 30.6cm2 anterior and 25.9cm2 posterior to the rectus muscle. The mean surface area of dye spread with posteriorly placed RSCs was 11.3cm2 anterior and 37.3cm2 posterior to the rectus muscle. The mean number of nerve roots stained with anteriorly and posteriorly placed RSCs was 3.8 and 2.7 respectively. Subcutaneous spread of dye was seen with one anterior RSC insertion. Peritoneal spread was seen with one anteriorly positioned RSC. Conclusions This study has demonstrated efficient nerve root infiltration with anteriorly and posteriorly positioned RSCs. It appears that dye spreads between the fibres of the rectus muscle rather than out laterally to the nerve roots when spreading from its initial compartment.

Anatomy of the L5 nerve root in the pelvis for safe sacral screw placement: a cadaveric study

2021 ◽  
pp. 1-6
Author(s):  
Shota Tamagawa ◽  
Takatoshi Okuda ◽  
Hidetoshi Nojiri ◽  
Tatsuya Sato ◽  
Rei Momomura ◽  
...  
Keyword(s):  
Nerve Root ◽  
Sagittal Plane ◽  
Pedicle Screws ◽  
Cadaveric Study ◽  
Nerve Roots ◽  
Nerve Root Injury ◽  
Inflection Points ◽  
Root Injury ◽  
The Right ◽  
Intervertebral Foramina

OBJECTIVE Previous reports have focused on the complications of L5 nerve root injury caused by anterolateral misplacement of the S1 pedicle screws. Anatomical knowledge of the L5 nerve root in the pelvis is essential for safe and effective placement of the sacral screw. This cadaveric study aimed to investigate the course of the L5 nerve root in the pelvis and to clarify a safe zone for inserting the sacral screw. METHODS Fifty-four L5 nerve roots located bilaterally in 27 formalin-fixed cadavers were studied. The ventral rami of the L5 nerve roots were dissected along their courses from the intervertebral foramina to the lesser pelvis. The running angles of the L5 nerve roots from the centerline were measured in the coronal plane. In addition, the distances from the ala of the sacrum to the L5 nerve roots were measured in the sagittal plane. RESULTS The authors found that the running angles of the L5 nerve roots changed at the most anterior surface of the ala of the sacrum. The angles of the bilateral L5 nerve roots from the right and left L5 intervertebral foramina to their inflection points were 13.77° ± 5.01° and 14.65° ± 4.71°, respectively. The angles of the bilateral L5 nerve roots from the right and left inflection points to the lesser pelvis were 19.66° ± 6.40° and 20.58° ± 5.78°, respectively. There were no significant differences between the angles measured in the right and left nerve roots. The majority of the L5 nerves coursed outward after changing their angles at the inflection point. The distances from the ala of the sacrum to the L5 nerve roots in the sagittal plane were less than 1 mm in all cases, which indicated that the L5 nerve roots were positioned close to the ala of the sacrum and had poor mobility. CONCLUSIONS All of the L5 nerve roots coursed outward after exiting the intervertebral foramina and never inward. To prevent iatrogenic L5 nerve root injury, surgeons should insert the S1 pedicle screw medially with an angle > 0° toward the inside of the S1 anterior foramina and the sacral alar screw laterally with an angle > 30°.

Quantitative magnetic resonance imaging of brainstem volumes, plaques, and surface area in the occipital regions of patients with multiple sclerosis

2006 ◽  
Vol 47 (4) ◽  
pp. 413-418 ◽  
Author(s):  
F. Alper ◽  
M. Kantarci ◽  
E. Altunkaynak ◽  
A. O. Varoglu ◽  
A. Karaman ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Magnetic Resonance ◽  
Surface Area ◽  
Occipital Lobe ◽  
Resonance Imaging ◽  
Secondary Progressive ◽  
Surface Areas ◽  
Relapsing Remitting ◽  
The Right ◽  
Occipital Lobes

Purpose: To determine brainstem volumes, number of plaques, and surface areas in the occipital lobes of patients with relapsing remitting multiple sclerosis (RRMS) and secondary progressive multiple sclerosis (SPMS), and to investigate whether there is any correlation between brainstem volume and the number/surface areas of plaque in the occipital lobes. Material and Methods: Magnetic resonance imaging was obtained on 14 relapsing-remitting (RR) and 13 secondary progressive (SP) MS patients and 26 female control subjects. The Cavalieri method was used by modern design stereology to measure brainstem volume. The point-counting grid was used to evaluate sclerotic plaque surface areas in the occipital lobe. The number of plaques in the imaging section was calculated. Results: Brainstem volumes for RR and SP with multiple sclerosis and control subjects were 3647 mm3, 3515 mm3, and 4517 mm3, respectively. Mean number of plaques in the right-left occipital lobe was found to be 2.7–3.4 in RR-MS and 5.2–2.8 in SP-MS. Mean plaque surface area in the right-left occipital lobe was determined to be 58.52–88.24 mm2 in RR MS and 124.3–64.82 mm2 in SP MS. Brainstem volumes were significantly reduced in both groups of patients with MS compared to controls ( P<0.01). Conclusion: Magnetic-resonance-estimated volume and surface area values in multiple sclerosis may facilitate our understanding of the clinical situation of patients and provide a simple index for evaluating therapeutic efficiency.

Recurrent spinal cord tethering by sacral nerve root following lipomyelomeningocele surgery

1991 ◽  
Vol 75 (1) ◽  
pp. 143-145 ◽  
Author(s):  
Giancarlo Barolat ◽  
Dale Schaefer ◽  
Sergio Zeme
Keyword(s):  
Nerve Root ◽  
Lower Extremities ◽  
Nerve Roots ◽  
Content Type ◽  
Surgical Exploration ◽  
Sacral Nerve Root ◽  
The Right ◽  
Progressive Weakness ◽  
Spinal Cord Tethering ◽  
Fine Print

✓ A 21-year-old woman had recurrent progressive weakness/hypesthesia and pain in both lower extremities. At the age of 5 and 19 years, she had undergone surgical resection of a lipomyelomeningocele at L5—S1. Surgical exploration revealed that the cord was tethered and pulled over to the side by an excessively short right S-1 nerve root. The contralateral L-5 and S-1 nerve roots were markedly stretched. Division of the right S-1 nerve root resulted in prompt disappearance of pain in the lower extremities and improvement in neurological function.

scholarly journals Surface area analysis in edentulous jaws of patients with skeletal class I

2011 ◽  
Vol 58 (4) ◽  
pp. 209-215 ◽  
Author(s):  
Srdjan Postic
Keyword(s):  
Surface Area ◽  
Class I ◽  
Anthropometric Parameter ◽  
Average Surface ◽  
Skeletal Class ◽  
Surface Areas ◽  
Significant Difference ◽  
Average Surface Area ◽  
The Right ◽  
Edentulous Jaws

Introduction. The surface area of edentulous jaw has been considered as an important functional and anthropometric parameter. The aim of this study was to assess the surface area of supporting tissue in edentulous jaws of patients with the skeletal class I. Material and Methods. Thin aluminum foils (0.5 mm of thickness) were adapted on plaster surfaces of 139 pairs of edentulous jaws casts. Foils were positioned on a millimeter-paper in order to measure their areas. Additionally, surface areas were measured using a mechanic plan-meter (G. Coradi, Zurich, Switzerland, serial no. 49823). The measurement error was 1%. Skeletal class of edentulous jaws was determined by analysis of lateral cephalometric radiographs, and assessing the ANB (SNA, SNB) angle. Results. The average surface area of edentulous upper jaws was 4654?407 mm2 in males, and 4212?368 mm2 in females. Edentulous lower jaws had average surface area of 2843?339 mm2 in males, and 2334?295 mm2 in females. Statistically significant difference (p<0.001) was found in comparison of surface areas and dimensions of upper and lower edentulous jaws in male and female. ANB values ranged from 2 to 4 degrees. Conclusion. The surface area is an important parameter in the analysis of edentulous jaws. Edentulous jaws in males had greater surface areas and dimensions as compared to females. Edentulous areas on the right side were not absolutely symmetric to areas on the left side.

scholarly journals PSIX-31 The effect of days on feed and trenbolone acetate + estradiol-17β implants on the dimensional measurements of serially harvested steer carcasses

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 333-334
Author(s):  
Lauren M Mayer ◽  
Tylo J Kirkpatrick ◽  
Sierra L Pillmore ◽  
Kaitlyn R Wesley ◽  
Kimberly B Cooper ◽  
...  
Keyword(s):  
Surface Area ◽  
Fixed Effects ◽  
Growth Promotion ◽  
Maximal Length ◽  
Trenbolone Acetate ◽  
Dorsal Edge ◽  
Exogenous Growth ◽  
Maximal Width ◽  
Dimensional Measurements ◽  
The Right

Abstract Charolais x Angus steers (n = 80) were serially harvested to evaluate the effect of days on feed and exogenous growth promotion on dimensional measurements of chilled carcasses. Steers were randomly distributed to treatment and harvest day in a 2 x 10 factorial design. Steers were paired by genetic similarity and randomly assigned one of two treatments; implanted with Revalor-XS (REV) on d 0 and d 190 or non-implanted control (CON). Four pairs were randomly assigned to market endpoints of 0, 42, 84, 126, 168, 210, 252, 294, 336, or 378 DOF. Forty-eight h after harvest, a digital image was obtained of the lateral aspect of the right side of each carcass in front of a grid containing 390 contrasting black and green squares (100 cm2 each). Images were individually calibrated to a common standard and digitally measured for 2-dimensional surface area and maximal carcass length and width. Maximal length was measured from the caudal tip of the hindshank to cranial edge of the foreshank and maximal width was measured from the dorsal edge of the crest to the ventral edge of the foreshank. Carcass dimensional measurements were analyzed using mixed models; fixed effects were implant treatment and DOF with d 0 BW as a covariate. No TRT x DOF interaction was observed (P ≥ 0.13) for any dependent variable. Steers administered REV yielded 516 cm2 greater (P &lt; 0.01) surface area than CON; moreover, surface area increased 21.0 cm2 /day. No TRT effect (P = 0.57) was observed for maximal length, however maximal width was 3.9 cm greater (P &lt; 0.01) for REV steers. Steer carcasses increased 0.16 cm/day in length and 0.07 cm/day in width. These data illustrate growth in carcass size following exogenous growth promotant administration and finishing steers for various lengths of time.

Cell morphology, volume, and surface area determinations from multilevel contouring within HVEM micrographs of serial sections and whole-cell mounts

1987 ◽  
Vol 45 ◽  
pp. 588-589
Author(s):  
M. Marko ◽  
A. Leith ◽  
D. Parsons
Keyword(s):  
Surface Area ◽  
Electron Micrographs ◽  
Cell Morphology ◽  
Individual Variation ◽  
Serial Section ◽  
Stereo Pair ◽  
Complex Structures ◽  
Serial Sections ◽  
Surface Areas ◽  
Computer Based

The use of serial sections and computer-based 3-D reconstruction techniques affords an opportunity not only to visualize the shape and distribution of the structures being studied, but also to determine their volumes and surface areas. Up until now, this has been done using serial ultrathin sections.The serial-section approach differs from the stereo logical methods of Weibel in that it is based on the Information from a set of single, complete cells (or organelles) rather than on a random 2-dimensional sampling of a population of cells. Because of this, it can more easily provide absolute values of volume and surface area, especially for highly-complex structures. It also allows study of individual variation among the cells, and study of structures which occur only infrequently.We have developed a system for 3-D reconstruction of objects from stereo-pair electron micrographs of thick specimens.

A rare variation in the formation of the lower trunk of the brachial plexus its embryological basis and clinical importance - a case report

2012 ◽  
Vol 6 (4) ◽  
pp. 49-52
Author(s):  
N Satyanarayana ◽  
R Guha ◽  
P Sunitha ◽  
GN Reddy ◽  
G Praveen ◽  
...  
Keyword(s):  
Case Report ◽  
Brachial Plexus ◽  
Upper Limb ◽  
Clinical Importance ◽  
Medical Sciences ◽  
Nerve Roots ◽  
Rare Variation ◽  
Lower Trunk ◽  
Male Cadaver ◽  
The Right

Brachial plexus is the plexus of nerves, that supplies the upper limb.Variations in the branches of brachial plexus are common but variations in the roots and trunks are very rare. Here, we report one of the such rare variations in the formations of the lower trunk of the brachial plexus in the right upper limb of a male cadaver. In the present case the lower trunk was formed by the union of ventral rami of C7,C8 and T1 nerve roots. The middle trunk was absent. Upper trunk formation was normal. Journal of College of Medical Sciences-Nepal,2011,Vol-6,No-4, 49-52 DOI: http://dx.doi.org/10.3126/jcmsn.v6i4.6727

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