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PubMedDate not supplied

Internal cardiac crux: two-dimensional echocardiography of normal and congenitally abnormal hearts.

The internal cardiac crux is an important anatomic landmark for the appreciation of both normal and congenitally altered anatomy. The four-chamber two-dimensional echocardiographic plane of section at the internal crux is the most feasible tomographic plane. The unique noninvasive access to the internal crux anatomy is frequently more sensitive and diagnostic than other imaging modalities, including angiography. This report describes the echocardiographic and anatomic landmarks of the normal crux and the more frequent congenital anomalies that alter these relationships.

Ebstein Anomaly↗
PubMed1996

Endoscopic anatomic distances on the lateral nasal wall.

OBJECTIVE: Functional endoscopic sinus surgery has become popularized during the last decade all over the world. Knowledge about the intricate anatomy of the nasal cavity, the ethmoid labyrinth, and related structures is of vital importance for the endoscopic sinus surgeon to avoid probable complications. This study was undertaken to provide a set of reference distances to the endoscopic surgeons. METHOD: In this surgical anatomic study, the distances of special anatomic landmarks from the anterior nasal spine were measured during the endoscopic dissection. The procedure was performed in 50 cadavers and measurements were done by the use of straight surgical guide under endoscopic vision. CONCLUSIONS: Optimum attention should be concentrated on vital structures such as optic nerve and internal carotid artery at posterior rhinobasis after approximately 75 mm. Surgical distances of critical anatomic landmarks on the lateral nasal wall from anterior nasal spine should be kept in mind during surgical interventions.

Adult↗
PubMed2002

Magnetic resonance imaging-based morphometry and landmark correlation of basal ganglia nuclei.

The two principle targets for deep brain stimulation or lesioning in patients with Parkinson's disease, the subthalamic nucleus (STN) and the globus pallidus internus (GPi), reveal a high degree of individual variability which is relevant to the planning of stereotactic operations. Both nuclei can clearly be delineated in T2WI spin echo MRI which was acquired under stereotactic conditions in general anesthesia before surgery. Such images of 35 patients served for retrospective morphometric analysis of different basal ganglia nuclei (STN, GP, red nucleus, and substantia nigra) and several anatomical landmarks (anterior and posterior commissure, maximum width of third ventricle, brain length and width). The average AC-PC distance was 25.74 mm (range 21 to 29 mm) and is in agreement with previous studies. On average, the center of the STN was located 12.65 mm (+/-1.3) lateral from the midline as determined 3 mm ventral to the intercommissural plane. The average width of the third ventricle was 7.05 mm (+/-2.41). The width of the third ventricle correlated with the laterality of the STN (r(right)=.78; r(left)=.83) and GP (r(right)=.76; r(left)=.68). Although to a lesser extent, significant correlations were also observed between the laterality of the STN and brain width, improving prediction of STN laterality by multiple linear regression analysis (r(right)=.82; r(left)=.87). Similarly, the laterality of GP correlated with brain width. In addition, gender-specific differences were detected. The STN and GP was located farther lateral in males which may be due to overall brain anatomy as gender-specific differences were also observed for brain width and length and AC-PC distance. MRI-based in vivo-localization of different basal ganglia nuclei extend statistical information from common histological brain atlases which are based on a limited number of brains. The correlations observed between different basal ganglia nuclei, i.e. the STN and GPi, and anatomical landmarks may be useful for surgical planning.

Adult↗
PubMed1988

A study of the height of intact alveolar bone on panoramic radiographs of adult patients.

This study describes a method of estimating alveolar bone height on panoramic radiographs by using constant anatomic landmarks as reference points and calculating ratios of given distances between certain of these landmarks in dentate patients with no radiographic evidence of horizontal bone loss. Measurements were performed on four different types of panoramic radiographs. Results determined for the maxillae and mandible were constant between the different types of panoramic films. Because of differences in the measurements obtained on the right and left sides on Panorex films that have been trimmed and spliced to remove anatomic overlap in the midline areas, this type of projection may not be suitable for analysis of the maxillary alveolar bone as described in this study. The use of the mental foramen as a constant anatomic landmark for analysis of mandibular alveolar bone on panoramic radiographs may not be feasible since it appears that it may not be possible to consistently determine the exact location of the foramen. The results of the present study suggest a difference of as much as 25% among patients in the same ratio in the maxillae and as much as 12% in the same ratio in the mandible. Therefore, the results may not be of significant value as "baseline" data to estimate alveolar bone loss at a given time after tooth loss. However, this method could prove valuable in serial studies where alveolar bone height for a single patient is compared at different times before and after tooth loss.

Adolescent↗
PubMed2005

Coronal ultra-thick multiplanar CT reconstructions (MPR) of the pelvis in the multiple trauma patient: an alternative for the initial conventional radiograph.

PURPOSE: Multiple trauma patients with clinically suspected pelvic fractures often directly undergo a CT scan. However, the initial portable pelvis film (PPF) for further follow-up is then not available. This study examines whether coronal ultra-thick multiplanar reconstructions from CT data are similar when compared with the initial PPF, thus having the potential to serve as an alternative baseline image. MATERIALS AND METHODS: Initial PPF and coronal ultra-thick multiplanar CT reconstructions of 33 multiple trauma patients with pelvic fractures were retrospectively analyzed by two independent radiologists with regard to image quality, visualization of anatomical landmarks, and diagnostic accuracy. The primary diagnosis of pelvic fractures was made by using thin axial CT images and thin slice coronal and sagittal reconstructions and served as the standard of reference. RESULTS: Coronal ultra-thick multiplanar CT reconstructions were superior to PPF regarding image adjustment (p < 0.02), absence of overlaying structures (p < 0.05), and overall image quality (p < 0.01). Visualization of most anatomical landmarks was similar with both modalities, except of the iliosacral joint and acetabular lines which were more accurately depicted on ultra-thick multiplanar CT reconstructions (p < 0.05). Diagnostic accuracy of coronal ultra-thick CT reconstructions was similar to PPF regarding most fracture types, except of a higher accuracy of coronal ultra-thick CT reconstructions for iliosacral joint and acetabular column fractures (p < 0.05). CONCLUSION: Coronal ultra-thick multiplanar CT reconstructions of the pelvis provide similar image quality and diagnostic accuracy compared to PPF and are therefore suited as alternative baseline image in multiple trauma patients who directly undergo CT.

Adult↗
PubMed2001

Ambulatory 24-hour double-probe pH monitoring: the importance of manometry.

OBJECTIVE: Historically, manometry has been used for sphincter localization before ambulatory 24-hour double-probe pH monitoring to ensure accurate placement of the probes. Recently, direct-vision placement (DVP), using transnasal fiberoptic laryngoscopy (TFL), has been offered as an alternative technique. Presumably, DVP might be used to precisely place the proximal (pharyngeal) pH probe; however, using DVP, there appears to be no way to accurately position the distal (esophageal) probe. The purpose of this study was to evaluate the accuracy of DVP for pH probe placement using manometric measurement as the gold standard. METHODS: Thirty patients undergoing pH monitoring participated in this prospective study. Each subject underwent manometric examination of the esophagus to determine the precise location of the upper and lower esophageal sphincters (UES and LES). In addition, external anatomic landmarks were used to estimate interprobe distances. A physician blinded to the manometry results then placed a pH catheter using DVP so that the proximal probe was located just above the UES. The results were recorded and compared with those obtained by manometry. RESULTS: Accurate DVP of the proximal pH probe was achieved in 70% (23 of 30) of the subjects. The use of external anatomic landmarks to estimate interprobe distance resulted in accurate positioning of the distal probe in only 40% (12 of 30) of the subjects. Using fixed interprobe distances of 15 cm and 20 cm, distal probe position accuracy was 3% (1 of 30) and 40% (12 of 30), respectively. Therefore, using DVP, the distal esophageal probe was in an incorrect position in 60% to 97% of subjects. CONCLUSION: For double-probe pH monitoring, the proximal probe can be accurately positioned by DVP; however, there is no precise way to determine the interprobe distance required to correctly position the distal pH probe. Failure to accurately position the distal probe results in grossly inaccurate esophageal acid-exposure times. Thus, manometry is needed to ensure valid double-probe pH monitoring data.

Esophagus↗
PubMed2004

Intramedullary screw fixation of the fifth metatarsal: an anatomic study and improved technique.

Intramedullary screw fixation has been found to be a reliable treatment for certain fractures of the fifth metatarsal. Techniques for this treatment have been described relying largely on intraoperative fluoroscopy. Ten human cadaver specimens had their fifth metatarsals osteotomized and underwent retrograde intramedullary pin placement. Anatomic landmarks and the location of the sural nerve in relation to this starting point were measured. The trajectory of a pin reducing the osteotomy was analyzed. Using the resultant starting point and guide pin trajectory, intramedullary screw placement was performed reliably without the aid of fluoroscopy. This study demonstrates that intramedullary screw fixation of proximal fifth metatarsal fractures may be performed with the use of anatomic landmarks, which decreases the amount of intraoperative fluoroscopy needed.

Bone Screws↗
PubMed2002

Computer assisted surgery for total knee arthroplasty.

The author has attempted to assess the value of computer-assisted surgery in arthroplasty of the knee. Basic requisites in TKR include adequate alignment and ligament balance. These requisites have become easier to meet as ancillary instrumentations have improved over time. Numerical tools are now available; they are sometimes presented as an essential technical step. The author reviews the various available options, with their advantages and disadvantages. Satisfactory alignment in the three planes classically relies on anatomic landmarks, the reliability of which is limited, and on ligament tension. Targeting systems, intra- or extramedullary, all have a margin of error. Computer-assisted surgery aims at increasing the precision of implant positioning and achieving optimal ligament balance. Among the systems currently available, a distinction must be made between active and passive systems. The former correspond to the "surgical robots", which are capable of performing the various parts of the operation following adequate preparation, at least regarding the bone cuts. Passive systems remain under control from the surgeon and assist him in positioning the cutting jigs. Among localization systems, a distinction must be made between optical and magnetic systems. Certain systems require preoperative imaging--usually CT scan--in order to first reconstruct a 3-D model of the knee. This step is time-consuming, but this will likely improve in the future. Image matching requires the use of a software, with specific landmarks defined preoperatively by the surgeon. Such systems may be used in cases with major deformities; their main drawback is the need for preoperative imaging. Other systems do not require preoperative imaging: a few points are identified by kinematic analysis of the hip, knee and ankle; they are used for 2-D or 3-D reconstruction. Computer-assisted systems may improve the precision in defining anatomic landmarks and achieving accurate location and orientation of the bone cuts, but this must still be validated. Computer-assisted surgery allows for intraoperative control of the orientation of bone cuts, the mechanical axes, the ligament balance and the range of motion. It remains to be demonstrated that using these systems will result into a clinically relevant benefit for the patient, as several of the prostheses widely implanted so far have demonstrated high survivorship rates at 15 or 20 years, so that the demonstration of a possible superiority would need considerable investment. Using these techniques does not solve all problems anyway. The patellar cut remains empirical, and these techniques also do not give any information about femoropatellar joint function. The present systems make use of the classical instrumentation, but it may be anticipated that instrumentations especially intended for computer-assisted surgery will be developed in the future. Regarding imaging, some possibilities have not yet been explored, such as plain radiography or fluoroscopy. Computer-assisted surgery should be of particular interest in revision arthroplasties, but it poses additional problem. The indications are relatively scarce however, and no major advances should be anticipated in the near future. On the whole, this is an emerging technical field. Development is slow, none of the available products is fully mature and caution is warranted in the face of enthusiastic reports and presentations. The value of computer-assisted surgery in TKR has not been demonstrated and its real usefulness still needs to be evaluated. It will, anyway, by no means exempt the surgeon from mastering the classical operative technique.

Arthroplasty, Replacement, Knee↗
PubMed2001

Multimodality image registration quality assurance for conformal three-dimensional treatment planning.

PURPOSE: We present a quality assurance methodology to determine the accuracy of multimodality image registration and fusion for the purpose of conformal three-dimensional and intensity-modulated radiation therapy treatment planning. Registration and fusion accuracy between any combination of computed tomography (CT), magnetic resonance (MR), and positron emission computed tomography (PET) imaging studies can be evaluated. METHODS AND MATERIALS: A commercial anthropomorphic head phantom filled with water and containing CT, MR, and PET visible targets was modified to evaluate the accuracy of multimodality image registration and fusion software. For MR and PET imaging, the water inside the phantom was doped with CuNO(3) and 18F-fluorodeoxyglucose (18F-FDG), respectively. Targets consisting of plastic spheres and pins were distributed throughout the cranium section of the phantom. Each target sphere had a conical-shaped bore with its apex at the center of the sphere. The pins had a conical extension or indentation at the free end. The contours of the spheres, sphere centers, and pin tips were used as anatomic landmark models for image registration, which was performed using affine coordinate-transformation tools provided in a commercial multimodality image registration/fusion software package. Four sets of phantom image studies were obtained: primary CT, secondary CT with different phantom immobilization, MR, and PET study. A novel CT, MR, and PET external fiducial marking system was also tested. RESULTS: The registration of CT/CT, CT/MR, and CT/PET images allowed correlation of anatomic landmarks to within 2 mm, verifying the accuracy of the registration software and spatial fidelity of the four multimodality image sets. CONCLUSIONS: This straightforward phantom-based quality assurance of the image registration and fusion process can be used in a routine clinical setting or for providing a working image set for development of the image registration and fusion process and new software.

Head and Neck Neoplasms↗
PubMed2000

Advanced surgical approach for selective amygdalohippocampectomy through neuronavigation.

OBJECTIVE: Selective removal of the mesiobasal temporal structures through the transsylvian approach was introduced by Yasargil and Wieser in 1982. This alternative to standard temporal lobectomy provides excellent outcomes for seizure control. Basic actions in the transsylvian fissure exposure mainly serve to orient the surgeon, and they carry the risk of vasospasm and vessel damage. The aim of our study was to reduce landmark-guided surgery steps through neuronavigation. METHODS: During a 14-month period, 16 selective amygdalohippocampectomies were performed with the aid of the SMN (Carl Zeiss, Inc., Thornwood, NY) or StealthStation (Sofamor Danek, Memphis, TN) optically guided systems. We added safety procedures to the operation (including intraoperative rereferencing, obtaining additional bony reference points before craniotomy, performing a small craniotomy and making an accurate dural incision, and using contrast medium for vessel visualization) to develop a method that relies on navigational systems without further orientation by anatomic landmarks. RESULTS: Originally, performing an amygdalohippocampectomy required exposing the sylvian fissure from the carotid bifurcation to 2 cm beyond the middle cerebral artery bifurcation, which exposed one-third of the insula. By determining the entry point at the limen insulae and the target at the tip of the temporal horn, the mandatory extent of the opening to the sylvian fissure can be projected. Therefore, the exposure of the fissure can be limited to exactly the extent required for the transventricular approach through the uncinate fasciculus. CONCLUSION: Computer-assisted surgery is an effective tool in eliminating the exposure of anatomic landmarks in selective amygdalohippocampectomy. This modification combines the precision of targeting with minimal cortical and vessel traumatization.

Adult↗
PubMed1982

Movements of the lumbar spine measured by three-dimensional X-ray analysis.

Techniques for the calculation from biplanar radiographs of the three-dimensional coordinates of anatomical landmarks on human lumbar vertebrae, and of the movements in three dimensions of the vertebrae between different positions of the spine are presented. The calculation of three-dimensional coordinates uses a calibration procedure based on direct linear transformation. Coordinate systems are used to define the orientations of each vertebra, and movements are derived from coordinate transformations between neighbouring vertebrae. The root mean square error in determining the absolute locations of anatomical landmarks was found to be less than 1 mm. For the movements of one vertebra relative to its neighbour the root mean square errors for translations were less than 2 mm and for rotations were less than 1.5 degrees. The system has been used to assess patients after spinal fusions and is currently being used in the diagnosis and assessment of patients with specific pathologies.

Humans↗
PubMed2003

Enhancing accuracy of magnetic resonance image fusion by defining a volume of interest.

We compared the registration accuracy for corresponding anatomical landmarks in two MR images after fusing the complete volume (CV) and a defined volume of interest (VOI) of both MRI data sets. We carried out contrast-enhanced T1-weighted gradient-echo and T2-weighted fast spin-echo MRI (matrix 256 x 256) in 39 cases. The CV and a defined VOI data set were each fused using prototype software. We measured and analysed the distance between 25 anatomical landmarks in predefined areas identified at levels L(1)-L(5) corresponding to defined axial sections. Fusion technique, landmark areas and level of fusion were further processed using a feed-forward neural network to calculate the difference which can be expected based on the measurements. We identified 975 landmarks for both T1- and T2-weighted images and found a significant difference in registration accuracy ( P<0.01) for all landmarks between CV (1.6+/-1.2 mm) and VOI (0.7+/-1.0 mm). From cranial (L(1)) to caudal (L(5)), mean deviations were: L(1) CV 1.5 mm, VOI 0.5 mm; L(2) CV 1.8 mm, VOI 0.4 mm; L(3) CV 1.7 mm, VOI 0.4 mm; L(4) CV 1.6 mm, VOI 0.6 mm; and L(5) CV 1.6 mm, VOI 1.6 mm. Neural network analysis predicted a higher accuracy for VOI (0.05-0.15 mm) than for CV fusion (0.9-1.6 mm). Deviations due to magnetic susceptibility changes between air and tissue seen on gradient-echo images can decrease fusion accuracy. Our VOI fusion technique improves image fusion accuracy to <0.5 mm by excluding areas with marked susceptibility changes.

Algorithms↗
PubMedDate not supplied

[Zuckerkandl tubercle of the thyroid gland (anatomo-surgical study: preliminary considerations)].

The presence of tubercle of Zuckerkandl (TZ) of the thyroid gland has been investigated in 20 specimens obtained from patients died from diseases not concerned to the cervical area. The project mas undertaken to elucidate the presence and the role of TZ as normal anatomical landmark. Special attempt has been paid to the relationships of the TZ with parathyroid gland and recurrent laryngeal nerve and the branches of the inferior thyroid artery. The tubercle was constantly found on the postero-medial surface of the thyroid lobe which showed constant relations with the branches of the inferior thyroid artery, superior parathyroid gland and recurrent laryngeal nerve. The outcomes of this preliminary report prove that TZ is an useful anatomical landmark to detect both superior parathyroid gland and laryngeal nerve in thyroid surgery.

Aged↗
PubMed2005

Cardiac three-dimensional magnetic resonance imaging and fluoroscopy merging: a new approach for electroanatomic mapping to assist catheter ablation.

BACKGROUND: Modern nonfluoroscopic mapping systems construct 3D electroanatomic maps by tracking intracardiac catheters. They require specialized catheters and/or dedicated hardware. We developed a new method for electroanatomic mapping by merging detailed 3D models of the endocardial cavities with fluoroscopic images without the need for specialized hardware. This developmental work focused on the right atrium because of the difficulties in visualizing its anatomic landmarks in 3D with current approaches. METHODS AND RESULTS: Cardiac MRI images were acquired in 39 patients referred for radiofrequency catheter ablation using balanced steady state free-precession sequences. We optimized acquisition and developed software for construction of detailed 3D models, after contouring of endocardial cavities with cross-checking of different imaging planes. 3D models were then merged with biplane fluoroscopic images by methods for image calibration and registration implemented in a custom software application. The feasibility and accuracy of this merging process were determined in heart-cast experiments and electroanatomic mapping in patients. Right atrial dimensions and relevant anatomic landmarks could be identified and measured in all 3D models. Cephalocaudal, posteroanterior, and lateroseptal diameters were, respectively, 65+/-11, 54+/-11, and 57+/-9 mm; posterior isthmus length was 26+/-6 mm; Eustachian valve height was 5+/-5 mm; and coronary sinus ostium height and width were 16+/-3 and 12+/-3 mm, respectively (n=39). The average alignment error was 0.2+/-0.3 mm in heart casts (n=40) and 1.9 to 2.5 mm in patient experiments (n=9), ie, acceptable for clinical use. In 11 patients, reliable catheter positioning and projection of activation times resulted in 3D electroanatomic maps with an unprecedented level of anatomic detail, which assisted ablation. CONCLUSIONS: This new approach allows activation visualization in a highly detailed 3D anatomic environment without the need for a specialized nonfluoroscopic mapping system.

Arrhythmias, Cardiac↗
PubMed1989

A porcine model for multiple musculocutaneous flaps.

The purpose of this study was to develop and describe in detail a reproducible porcine model for musculocutaneous flap study. The model was required to demonstrate the following: 1. consistent, easily identifiable anatomical landmarks for muscles and muscular vascular pedicles; 2. flap survival, consistent with the musculocutaneous perforator arrangement of blood supply; 3. ease of islanded- or free-flap formation; 4. arrangement of flaps on each animal, allowing paired studies of control and experimental flaps; and 5. a maximum number of flaps per animal, without undue morbidity or mortality. Pilot dissections were made of the pectoralis, trapezius, latissimus dorsi, gracilis, biceps femoris, and tensor fasciae latae muscles and their major vascular pedicles. After establishing the anatomical landmarks, we formed musculocutaneous flaps at each site to verify the above five requirements. A total of 72 muscle/vessel pedicle dissections were performed, incorporating formation of 61 island musculocutaneous flaps. The skin component overlying an islanded muscle block survived in 60 instances, confirming the reliability of the flap model. We concluded that five pairs of musculocutaneous flaps could be fashioned on one pig, using the bilateral control/experimental paradigm if desired. The pectoralis, latissimus dorsi, trapezius, gracilis, and biceps femoris muscles were used. The ventral muscle group (pectoralis, gracilis) was raised in one operating session, and the lateral muscles (trapezius, latissimus dorsi, biceps femoris) were raised in one further session per side. Three new porcine flaps are described--the pectoralis, biceps femoris, and trapezius. Morbidity was confined to mild splinting of the limbs for one day. This is also the first example of the use of ten musculocutaneous island flaps on one pig, and represents an opportunity for performing physiological, pathological, or pharmacological experiments on the musculocutaneous flap.

Animals↗
PubMed1990

Stature estimation from fragmentary femora: a revision of the Steele method.

The skeletal remains presented to forensic anthropologists are often fragmentary. Previously described methods of estimating stature from segments of long bones have not proved satisfactory because of the difficulty involved in identifying the precise anatomical landmarks by which they are defined. This study represents an assessment of the feasibility of stature estimation from fragmentary femora. A sample of 200 males and females, blacks and whites (total sample = 800), was obtained from the Terry Collection. New regression equations for the estimation of maximum femur length and stature from three well-defined and easy-to-measure segments of the femur are presented. This technique represents an improvement over methods currently in use for estimating stature from femur fragments; the location of the anatomical landmarks and the accuracy of the prediction are enhanced. The applicability of these formulae to a modern forensic sample is addressed with regard to secular trends in stature increase and changes in body segment proportions.

Anthropology, Physical↗
PubMed1996

A surgical guide for identifying the lateral femoral circumflex vessels during free vascularized fibular transfer for avascular necrosis of the femoral head.

Free vascularized fibular transfer for avascular necrosis of the femoral head was developed in an attempt to preserve, rather than replace, the femoral head. In this procedure, the peroneal vessels of the autogenous fibular graft are anastomosed to recipient branches of the lateral femoral circumflex vessels. A problem with this procedure has been the difficulty in locating the lateral femoral circumflex vessels. An anatomic and surgical study was conducted to seek a consistent anatomic landmark for use in isolating these vessels. Ten cadaveric and 29 surgical hip dissections were performed. A falx, or fascial band, was consistently found approximately 10 cm distal to the anterior superior iliac spine; it is attached to the anterior intertrochanteric line of the proximal femur, with additional attachments to the investing fascia of the tensor fascia lata and rectus femoris muscles. Cautious release of this falx from superficial to deep leads to the fat layer surrounding the lateral femoral circumflex vessels. This study has shown that an anatomic landmark exists, which consistently leads to location of the lateral femoral circumflex vessels during a free vascularized fibular transfer. By incorporating the use of this landmark ito the authors' surgical technique, they have significantly reduced surgical dissection time and have provided a safe method for isolating the recipient vessels during this challenging operation.

Angiography↗
PubMed2005

[Modified "Wigand" technique used in the revision endoscopic sinus surgery].

OBJECTIVE: To introduce the modified "Wigand" revision endoscopic sinus surgical technique and evaluate the effect for the patients with recurrent type 3 nasal chronic sinusitis and polyps. METHOD: One hundred and thirteen cases with recurrent type 3 disease of nasal chronic sinusitis and polyps had been operated by the way of "from anterior-to-posterior-to-anterior" modified "Wigand" revision endoscopic sinus surgery. Take choanae, maxillary sinus ostium, the remnant of middle turbinate and the roof and lateral wall of sphenoid sinus as four stable anatomic landmarks. All the patients were operated bilaterally total ethmoidectomy at the same time. RESULT: Seventy-six cases of 113 (67.3%) were cured, 31 (27.4%) were improved, 6 (5.3%) were of no effect, and the total effective rate was 94.7%; the average volume of blood during surgery was 165 ml. The total operating time was no more than 1 hour. No severe complication was observed. CONCLUSION: "From anterior-to-posterior-to-anterior" modified "Wigand" technique is a safe, quick and effective revision endoscopic sinus surgery. Four stable anatomic landmarks are helpful for us to resect the total ethmoid thoroughly and prevent severe complications.

Adolescent↗