VIRTOPSY: minimally invasive, imaging-guided virtual autopsy

Invasive "body-opening" autopsy represents the traditional means of postmortem investigation in humans. However, modern cross-sectional imaging techniques can supplement and may even partially replace traditional autopsy. Computed tomography (CT) is the imaging modality of choice for two- and three-dimensional documentation and analysis of autopsy findings including fracture systems, pathologic gas collections (eg, air embolism, subcutaneous emphysema after trauma, hyperbaric trauma, decomposition effects), and gross tissue injury. Various postprocessing techniques can provide strong forensic evidence for use in legal proceedings. Magnetic resonance (MR) imaging has had a greater impact in demonstrating soft-tissue injury, organ trauma, and nontraumatic conditions. However, the differences in morphologic features and signal intensity characteristics seen at antemortem versus postmortem MR imaging have not yet been studied systematically. The documentation and analysis of postmortem findings with CT and MR imaging and postprocessing techniques ("virtopsy") is investigator independent, objective, and noninvasive and will lead to qualitative improvements in forensic pathologic investigation. Future applications of this approach include the assessment of morbidity and mortality in the general population and, perhaps, routine screening of bodies prior to burial.

Treatment of tibial fractures with plates using minimally invasive percutaneous osteosynthesis in dogs and cats

OBJECTIVES: The aim of the here described case series was to develop and evaluate the minimally invasive percutaneous osteosynthesis for the plate fixation of tibial fractures in dogs and cats. METHODS: Six dogs and four cats with shaft fractures of the tibia were treated using minimally invasive percutaneous osteosynthesis. Follow-up radiographs four to six weeks after fracture fixation were evaluated for fracture healing. For the long-term follow-up (minimum 2.4 years), owners were contacted by phone to complete a questionnaire. RESULTS: All fractures healed without the need for a second procedure. Follow-up radiographs obtained after four to six weeks in seven cases showed advanced bony healing with callus formation and filling of the fracture gaps with calcified tissue in all seven. All the patients had a good to excellent long-term result with full limb function. The time needed for regaining full limb use was two to three months. CLINICAL SIGNIFICANCE: Minimally invasive percutaneous osteosynthesis seems to be a useful technique for the treatment of tibial shaft fractures in dogs and cats.

Non-photorealistic rendering of virtual implant models for computer-assisted fluoroscopy-based surgical procedures

Surgical navigation systems visualize the positions and orientations of surgical instruments and implants as graphical overlays onto a medical image of the operated anatomy on a computer monitor. The orthopaedic surgical navigation systems could be categorized according to the image modalities that are used for the visualization of surgical action. In the so-called CT-based systems or 'surgeon-defined anatomy' based systems, where a 3D volume or surface representation of the operated anatomy could be constructed from the preoperatively acquired tomographic data or through intraoperatively digitized anatomy landmarks, a photorealistic rendering of the surgical action has been identified to greatly improve usability of these navigation systems. However, this may not hold true when the virtual representation of surgical instruments and implants is superimposed onto 2D projection images in a fluoroscopy-based navigation system due to the so-called image occlusion problem. Image occlusion occurs when the field of view of the fluoroscopic image is occupied by the virtual representation of surgical implants or instruments. In these situations, the surgeon may miss part of the image details, even if transparency and/or wire-frame rendering is used. In this paper, we propose to use non-photorealistic rendering to overcome this difficulty. Laboratory testing results on foamed plastic bones during various computer-assisted fluoroscopybased surgical procedures including total hip arthroplasty and long bone fracture reduction and osteosynthesis are shown.

Early implant placement following single-tooth extraction in the esthetic zone: biologic rationale and surgical procedures

Early implant placement is one treatment option for implant therapy following single-tooth extraction in the anterior maxilla. The surgical technique presented here is characterized by tooth extraction without flap elevation, a 4- to 8-week soft tissue healing period, implant placement in a correct three-dimensional position, simultaneous contour augmentation on the facial aspect with guided bone regeneration using a bioabsorbable collagen membrane combined with autogenous bone chips and a low-substitution bone filler, and tension-free primary wound closure. The surgical step-by-step procedure is presented with a case report. In addition, the biologic rationale is discussed.

A retrospective analysis of patients referred for implant placement to a specialty clinic: indications, surgical procedures, and early failures

Purpose: This retrospective study analyzed the pool of patients referred for treatment with dental implants over a 3-year period in a referral specialty clinic. Materials and Methods: All patients receiving dental implants between 2002 and 2004 in the Department of Oral Surgery and Stomatology, University of Bern, were included in this retrospective study. Patients were analyzed according to age, gender, indications for implant therapy, location of implants, and type and length of implants placed. A cumulative logistic regression analysis was performed to identify and analyze potential risk factors for complications or failures. Results: A total of 1,206 patients received 1,817 dental implants. The group comprised 573 men and 633 women with a mean age of 55.2 years. Almost 60% of patients were age 50 or older. The most frequent indication for implant therapy was single-tooth replacement in the maxilla (522 implants or 28.7%). A total of 726 implants (40%) were inserted in the esthetically demanding region of the anterior maxilla. For 939 implants (51.7%), additional bone-augmentation procedures were required. Of these, ridge augmentation with guided bone regeneration was performed more frequently than sinus grafting. Thirteen complications leading to early failures were recorded, resulting in an early failure rate of 0.7%. The regression analysis failed to identify statistically significant failure etiologies for the variables assessed. Conclusions: From this study it can be concluded that patients referred to a specialty clinic for implant placement were more likely to be partially edentulous and over 50 years old. Single-tooth replacement was the most frequent indication (> 50%). Similarly, additional bone augmentation was indicated in more than 50% of cases. Adhering to strict patient selection criteria and a standardized surgical protocol, an early failure rate of 0.7% was experienced in this study population

Minimally invasive strabismus surgery (MISS) for inferior obliquus recession

PURPOSE: To present a novel, minimally invasive strabismus surgery (MISS) technique for inferior obliquus recessions. METHODS: Graded MISS inferior obliquus recessions were performed in 20 eyes of 15 patients by applying two small conjunctival cuts, one at the insertion of inferior obliquus and another where the scleral anchoring of the muscle occurred. RESULTS: The amount of recession was 12.2 +/- 2.3 mm (range 6 to 14 mm). The vertical deviation, which was measured in 25 degrees of adduction, decreased from preoperatively 12.8 degrees +/- 5.6 degrees to 2.7 degrees +/- 2.2 degrees (p < 0.0001) at 6 months. LogMAR visual acuity was preoperatively -0.10 +/- 0.17 and at 6 months -0.14 +/- 0.22 (p > 0.1). In one eye (2.5%) the two cuts had to be joined because of excessive bleeding. Binocular vision improved in eight patients, remained unchanged in six patients, and decreased from 30 to 60 arcsec in one patient (p > 0.1). Conjunctival and lid swelling were hardly visible on the first postoperative day in primary gaze position in 10/20 (50%) of eyes. Five of the eyes (25%) had mild and five (25%) moderate visibility of surgery. One patient out of 15 (7%) needed repeat surgery because of insufficient reduction of the sursoadduction within the first 6 months. The dose-effect relationship 6 months postoperatively for an accommodative near target at 25 degrees adduction was 0.83 degrees +/- 0.43 degrees per mm of recession. CONCLUSIONS: This study demonstrates that small-incision, minimal dissection inferior obliquus graded recessions are feasible and effective to improve ocular alignment in patients with strabismus sursoadductorius.

Minimally invasive strabismus surgery for rectus muscle posterior fixation

AIMS: To present a novel, minimally invasive strabismus surgery (MISS) technique for rectus muscle posterior fixation. METHODS: This study reports the results of 32 consecutive MISS rectus muscle posterior fixation surgeries performed on 19 patients by applying only two small L-shaped openings where the two retroequatorial scleromuscular sutures were placed. RESULTS: On the first postoperative day, in primary position, redness was hardly visible in 16 eyes (50%) and only moderate redness was visible in 6 eyes (19%). No serious complication occurred. Preoperative visual acuity and refraction remained unchanged at 6 months (p > 0.1). The preoperative convergence excess (n = 13) decreased from 10.3 +/- 4.1 to 5.2 +/- 4.0 degrees at 6 months (p < 0.005). In all patients operated on for gaze incomitance (n = 6) improvement was achieved at 6 months. CONCLUSIONS: This study shows that keyhole minimal-dissection rectus muscle posterior fixation surgery is feasible and effective to improve ocular alignment. The MISS technique seems to be superior in the direct postoperative period since only minimal conjunctival swelling and no corneal complications were observed.

Minimally invasive strabismus surgery for horizontal rectus muscle reoperations

AIMS: To study if minimally invasive strabismus surgery (MISS) is suitable for rectus muscle reoperations. METHODS: The study presents a series of consecutive patients operated on by the same surgeon at Kantonsspital St Gallen, Switzerland with a novel MISS rectus muscle reoperation technique. Surgery is done by applying two small radial cuts along the muscle insertion. Through the tunnel obtained after muscle separation from surrounding tissue, a recession, advancement or plication is performed. RESULTS: In 62 eyes of 51 patients (age 35.4 (SD 16.3) years) a total of 86 horizontal rectus muscles were reoperated. On the average, the patients had 2.1 strabismus surgeries previously. Preoperative logMAR visual acuity was 0.38 (0.82) compared with 0.37 (0.83) at 6 months (p>0.1). On the first postoperative day, in the primary gaze position conjunctival and lid swelling and redness was hardly visible in 11 eyes, discrete in 15 eyes, moderate in 11 eyes and severe in 15 eyes. One corneal dellen and one corneal erosion occurred, which both quickly resolved. The preoperative deviation at distance for esodeviations (n = 15) of 12.5 (8.5) degrees decreased to 2.6 (7.8) degrees at 6 months (p<0.001). For near, a decrease from 12.0 (10.1) degrees to 2.9 (1.6) degrees was observed (p<0.001). The preoperative deviation at distance for exodeviations (n = 35) of -16.4 (8.5) degrees decreased to -7.9 (6.5) degrees at 6 months (p<0.005). For near, a decrease from -16.5 (11.4) degrees to -2.9 (1.5) degrees was observed (p<0.005). Within the first 6 months, only one patient had a reoperation. At month 6, in four patients a reoperation was planned or suggested by us because of unsatisfactory alignment. No patient experienced persistent diplopia or necessitated a reoperation because of double vision. Stereovision improved at month 6 compared with preoperatively (p<0.01). CONCLUSIONS: The study demonstrates that a small-cut, minimal dissection technique allows to perform rectus muscle reoperations. The MISS technique seems to reduce conjunctival and lid swelling in the direct postoperative period.

Comparison of a new, minimally invasive strabismus surgery technique with the usual limbal approach for rectus muscle recession and plication

AIM: To present a novel, minimally invasive strabismus surgery (MISS) technique for rectus muscle operations. METHODS: In this prospective study with a non-concurrent, retrospective comparison group, the first 20 consecutive patients treated with MISS were matched by age, diagnosis and muscles operated on, with 20 patients with a limbal opening operated on by the same surgeon at Kantonsspital, St Gallen, Switzerland. A total of 39 muscles were operated on. MISS is performed by applying two small radial cuts along the superior and inferior muscle margin. After muscle separation from surrounding tissue, a recession or plication is performed through the resulting tunnel. Alignment, binocular single vision, variations in vision, refraction, and number and types of complications during the first 6 postoperative months were registered. RESULTS: Visual acuity decreased at postoperative day 1 in both groups. The decrease was less pronounced in the group operated on with MISS (difference of decrease 0.14 logMAR, p<0.001). An abnormal lid swelling at day 1 was more frequent in the control group (21%, 95% confidence interval (CI) 9% to 41%, 5/24 v 0%, 95% CI 0 to 13%, 0/25, p<0.05). No significant difference was found for final alignment, binocular single vision, other visual acuities, refractive changes or complications (allergic reactions, dellen formation, abnormal conjuctival findings). A conversion to a limbal opening was necessary in 5% (95% CI 2% to 17%, 2/39) of muscles. CONCLUSIONS: This study shows that this new, small-incision, minimal dissection technique is feasible. The MISS technique seems to be superior in the direct postoperative period as better visual acuities and less lid swelling were observed. Long-term results did not differ in the two groups.

Radiation metabolomics. 1. Identification of minimally invasive urine biomarkers for gamma-radiation exposure in mice

Gamma-radiation exposure has both short- and long-term adverse health effects. The threat of modern terrorism places human populations at risk for radiological exposures, yet current medical countermeasures to radiation exposure are limited. Here we describe metabolomics for gamma-radiation biodosimetry in a mouse model. Mice were gamma-irradiated at doses of 0, 3 and 8 Gy (2.57 Gy/min), and urine samples collected over the first 24 h after exposure were analyzed by ultra-performance liquid chromatography-time-of-flight mass spectrometry (UPLC-TOFMS). Multivariate data were analyzed by orthogonal partial least squares (OPLS). Both 3- and 8-Gy exposures yielded distinct urine metabolomic phenotypes. The top 22 ions for 3 and 8 Gy were analyzed further, including tandem mass spectrometric comparison with authentic standards, revealing that N-hexanoylglycine and beta-thymidine are urinary biomarkers of exposure to 3 and 8 Gy, 3-hydroxy-2-methylbenzoic acid 3-O-sulfate is elevated in urine of mice exposed to 3 but not 8 Gy, and taurine is elevated after 8 but not 3 Gy. Gene Expression Dynamics Inspector (GEDI) self-organizing maps showed clear dose-response relationships for subsets of the urine metabolome. This approach is useful for identifying mice exposed to gamma radiation and for developing metabolomic strategies for noninvasive radiation biodosimetry in humans.

Acute lower gastrointestinal hemorrhage: minimally invasive management with microcatheter embolization

PURPOSE: To evaluate the efficacy of superselective embolization therapy in the management of acute lower gastrointestinal (LGI) hemorrhage, including any bleeding distal to the ligament of Treitz. MATERIALS AND METHODS: Between June and August 2007, 20 patients with acute LGI bleeding underwent superselective transcatheter arterial embolization (TAE) at the authors' institution. The bleeding had different causes. All patients were treated with use of microcatheters. The following embolic agents were used: microcoils (n = 16), polyvinyl alcohol (PVA) particles (n = 2), and a combination of microcoils and PVA particles (n = 2). Outcome measures included technical success (complete cessation of bleeding as documented at completion angiography), clinical success (resolution of signs or symptoms of LGI bleeding within 30 days after TAE), and the rate of major and minor complications. RESULTS: The identified bleeding sources were as follows: jejunal branch, branch of middle colic artery, branch of ileocolic artery, ileal branch, branch of left colic artery, branch of sigmoid artery, branch of the superior rectal artery, and branch of the middle rectal artery. Technical success with effective control of active bleeding was achieved in all patients (100%). Clinical success attributed to TAE was documented in 18 of the 20 patients (90%). Major complications included death due to pulmonary embolism, heart infarction, and multiorgan failure in the 3rd week after TAE; a procedure-related colonic infarction occurred in one patient. A minor complication occurred in one patient who developed a groin hematoma. CONCLUSIONS: Superselective embolization may be used for effective, minimally invasive control of acute LGI bleeding.

Cone Beam and Micro-Computed Tomography Validation of Manual Array Insertion for Minimally Invasive Cochlear Implantation

Delivering cochlear implants through a minimally invasive tunnel (1.8 mm in diameter) from the mastoid surface to the inner ear is referred to as direct cochlear access (DCA). Based on cone beam as well as micro-computed tomography imaging, this in vitro study evaluates the feasibility and efficacy of manual cochlear electrode array insertions via DCA. Free-fitting electrode arrays were inserted in 8 temporal bone specimens with previously drilled DCA tunnels. The insertion depth angle, procedural time, tunnel alignment as well as the inserted scala and intracochlear trauma were assessed. Seven of the 8 insertions were full insertions, with insertion depth angles higher than 520°. Three cases of atraumatic scala tympani insertion, 3 cases of probable basilar membrane rupture and 1 case of dislocation into the scala vestibuli were observed (1 specimen was damaged during extraction). Manual electrode array insertion following a DCA procedure seems to be feasible and safe and is a further step toward clinical application of image-guided otological microsurgery.

Novel prototype sewing device, EndoSew ® , for minimally invasive surgery: an extracorporeal ileal conduit construction pilot study in 10 patients

What's known on the subject? and What does the study add? The EndoSew® prototype was first tested in a porcine model several years ago. The investigators found it both simple to master and reliable, its greatest advantage being a 2.4-fold time saving compared with straight laparoscopic suturing. In addition to that publication, there is a single case report describing the performance of an open EndoSew® suture to close parts (16 cm) of an ileal neobladder. The time for suturing the 16 cm ileum was 25 min, which is in line with our experience. The knowledge on this subject is limited to these two publications. We report on the first consecutive series of ileal conduits performed in humans using the novel prototype sewing device EndoSew®. The study shows that the beginning and the end of the suture process represent the critical procedural steps. It also shows that, overall, the prototype sewing machine has the potential to facilitate the intracorporeal suturing required in reconstructive urology for construction of urinary diversions. Objective To evaluate the feasibility and safety of the novel prototype sewing device EndoSew® in placing an extracorporeal resorbable running suture for ileal conduits. Patients and Methods We conducted a prospective single-centre pilot study of 10 consecutive patients undergoing ileal conduit, in whom the proximal end of the ileal conduit was closed extracorporeally using an EndoSew® running suture. The primary endpoint was the safety of the device and the feasibility of the sewing procedure which was defined as a complete watertight running suture line accomplished by EndoSew® only. Watertightness was assessed using methylene blue intraoperatively and by loopography on postoperative days 7 and 14. Secondary endpoints were the time requirements and complications ≤30 days after surgery. Results A complete EndoSew® running suture was feasible in nine patients; the suture had to be abandoned in one patient because of mechanical failure. In three patients, two additional single freehand stitches were needed to anchor the thread and to seal tiny leaks. Consequently, all suture lines in 6/10 patients were watertight with EndoSew® suturing alone and in 10/10 patients after additional freehand stitches. The median (range) sewing time was 5.5 (3–10) min and the median (range) suture length was 4.5 (2–5.5) cm. There were no suture-related complications. Conclusions The EndoSew® procedure is both feasible and safe. After additional freehand stitches in four patients all sutures were watertight. With further technical refinements, EndoSew® has the potential to facilitate the intracorporeal construction of urinary diversions.