Cavity Defects Research Articles

Latissimus dorsi muscle free flap revisited: A novel endoscope‐assisted approach

Achieving a functionally favorable and aesthetically acceptable outcome in oncologic and reconstructive surgery is important in the current era. Latissimus dorsi (LD) flap is traditionally performed with a large incision in lateral position. We report an endoscope-assisted harvest of LD muscle free flap in supine position to avoid a large scar and facilitate a two-team approach for oral cavity reconstruction. Consecutive case series. Four consecutive patients underwent LD muscle free flap for various oral cavity reconstructions. LD muscle free flaps were harvested under endoscope assistance. Endoscope-assisted LD free-flap harvest allowed a small incision in the axillary pit, which can be easily concealed without change of patient position, resulting in shortened operative time. Endoscopic harvest caused no acute complications, and donor site morbidity was minimal. Reconstructions with endoscope-assisted LD muscle free flap of the oral cavity defect site were successful in all cases. Endoscope-assisted LD muscle free flap is a feasible and practical option for the reconstruction of selective oral cavity defects with aesthetically excellent donor site scar.

Study on Local Extrusions' Effects on Improvement of Die Casting Prismatic Parts' Forming Quality

This paper analyzes traditional die casting process to find out the reasons that cause shrinkage cavity and porosity defects in casting. An optimized process of die casting by using local extrusion is proposed. A device used in local extrusion which realizes forcing compensating contraction on key parts of crankcase is designed and the parameters of local extrusion process are discussed. Compared the mechanical properties and microstructure of local extrusion used in die casting production with traditional. It shows that local extrusion used in die casting production can not only achieve the aim eliminating shrinkage porosity and cavity of a casting but also can refine grain to improve the mechanical properties.

Reconstruction of through-and-through oromandibular defects by the double-skin paddle fibula osteocutaneous flap: Can the skin paddle always be divided?

Reconstruction of the through-and-through defects of the oral cavity, involving oral mucosa, bone, and external skin is a major challenge. A single fibula osteocutaneous flap providing two skin islands is an option for such composite reconstruction. The number, location, and size of skin perforators were studied in the distal two thirds of the lower legs in 22 cases of fibula osteocutaneous flap mandibular reconstruction, and whether the skin paddle of the fibula flap could always be divided completely based on two distal perforators was examined. In this study, only 50% of the flaps had two or more distal perforators; thus, it was concluded that the skin paddle of the fibula osteocutaneous flap could not always be divided based on two distal skin perforators.

Platysma myocutaneous flap - its current role in reconstructive surgery of oral soft tissue defects

Reconstruction of oral soft-tissue defects following resection of oral carcinomas can be achieved using various techniques including microsurgical tissue transfer. However, there seems to be a role for regional or local flaps. Small to medium-size defects can be functionally reconstructed with the platysma myocutaneous flap as an excellent choice particularly in medically compromised patients not being eligible for free tissue transfer. The present paper reviews the indication, surgical technique, and complications following reconstruction of defects of the oral cavity with the platysma myocutaneous flap.

Craniofacial malformations in prenatal ultrasound evaluation. Literature review

Fetal face is the key anatomical location, both psychologically and clinically for the mother and the clinician. Ultrasound prenatal examination of the maxillofacial region allows to evaluate the fetal face in the first weeks of gestation. In ambulatory intravaginal ultrasound, sensitivity of the facial defect detection is 20-30% in cases without the risk of TORCH and fetal abnormalities, which may arouse suspicion of the presence of facial malformation. Facial defects form a wide group of pathologies. Unfortunately challenges connected with 2D and 3D ultrasound imaging cause frequent misdiagnoses in early gestation. Maxillofacial abnormalities can be solitary or they can coexist with other abnormalities or syndromes. In case of detecting a facial defect, a precise and thorough ultrasound of whole fetal body is necessary whereas in case of detecting any fetal body abnormality a precise and thorough ultrasound examination of the fetal face is obligatory Unfortunately most contemporary prenatal ultrasound standards propose only the overall "face and orbits" evaluation of the fetal face. The evaluation is difficult at 23 and 24 weeks of gestation and seems to be rather challenging in the third trimester of gestation. Not only facial malformations but also facial dimorphic features may lead to the suspicion of genetic syndrome and they may be extremely important in making correct diagnosis. Attempts at standardization in fetal face ultrasound evaluation have proved to be extremely difficult. Advantages of 2D ultrasound over 3D ultrasound and 3D ultrasound over 2D ultrasound in fetal face evaluation have been a topic of much debate. Most typically fetal face is examined with 2D ultrasound in a few basic planes: coronary sagittal, frontal and oblique. The planes preferred in the evaluation of facial structures are discussed in details in the paper Fetal facial defects evaluated in the ultrasound examination may be divided into a few main groups: examination of the orbit and eyeball defects, examination of the external nose and nasal cavity defects, examination of the cleft defects involving the lip, hard and soft palate which may be unilateral or bilateral, examination of external ear defects, examination of mandibular defects and detection of fetal tumors. 3D ultrasound evaluation of the fetal face is extremely useful in visualization of the face, thus presenting a problem to parents and clinicians. Prenatal ultrasound examination provides necessary and extremely useful data concerning fetal facial abnormalities, which allows to plan care and further treatment including interventions in pediatric ENT, pediatric surgery and plastic surgery areas. Cooperation of ultrasound diagnostician and clinicians taking care of a child in the future is therefore necessary when designing treatment scheme in cases of fetal facial defects.

Oral reconstruction with submental flap

Background:Submental flap is a useful technique for reconstruction of medium to large oral cavity defects. Hair bearing nature of this flap in men makes it less appropriate. Therefore, deepithelialized variant is introduced to overcome the problem of hair with this flap. Recently, application of this flap has been introduced in maxillofacial trauma patients.Materials and Methods:Deepithelialized orthograde submental flap is used for the reconstruction of oral cavity mucosal defects.Results:Four cases including two trauma patients and two squamous cell carcinomas (SCCs) of oral cavity were treated using deepithelialized orthograde submental flap. There were no complications in all four patients and secondary epithelialization occurred in raw surface of the flap which was exposed to oral cavity.Conclusion:Deepithelialized orthograde submental flap is very effective in reconstruction of oral cavity in men. The problem of hair is readily solved using this technique without jeopardizing flap blood supply.

Use of a combined latissimus dorsi scapular free flap revascularized with vein grafting to the internal mammary artery in a vessel-depleted and previously irradiated neck

For patients who have extensive prior treatment, use of the internal mammary artery/vein (IMA/IMV) or cephalic vein has been shown to be a reliable option. Additionally, for those patients who require vascularized bone and extensive soft tissue reconstruction, the combined latissimus dorsi scapular free flap (mega-flap) is an excellent option. We reviewed 3 cases in which extensive prior surgery and radiation precluded the use of traditional recipient vessels in the neck. Three patients with major jaw deformities were reconstructed using a mega-flap. In all cases, saphenous vein grafting succeeded in achieving arterial inflow from the IMA to the subscapular artery. Venous egress was achieved using a vein graft to the IMV in 1 patient and a transposed cephalic vein in the remaining 2 patients. This approach of restoring large oral cavity defects for patients with extensive prior therapy and comorbid conditions has proven to be reliable and reproducible.

Anterior Superficial Temporal Artery Island Flap

There are many options for the repair of intraoral defects. Today, free radial forearm or anterolateral thigh perforator flap is the first choice for the repair of intraoral defects. However, the importance of regional flaps is still maintained for patients whose medical condition is inappropriate for a long surgery and anesthesia time. In this report, we present our clinical experience with 9 patients who underwent retromolar trigone, buccal mucosal, gingival, and mouth floor reconstruction with anterior superficial temporal artery island flap (ASTIF) which has not been described in the literature before. Their mean age is 49 (27-85) years. ASTIF dimensions used for the reconstructions ranged from 3 × 5 to 8 × 16 cm. No partial or total flap necrosis was seen in any of the patients; only 3 patients had venous congestion problem for the first 3 days of the surgery, but they all healed well. Five patients had squamous cell carcinoma, 2 patients had squamous cell carcinoma with local recurrence, 1 patient had adenocarcinoma, and 1 patient had mandibular osteocarcinoma. Patients were followed for a minimum of 6 months postoperatively (average 12 months, range 6 to 24 months). ASTIF provides an excellent alternative for reconstructing defects of the oral cavity for some patients who have significant comorbid conditions or specific contraindications to free tissue transfer. At the same time, the combination with the free flaps increases the success of the restoration. Level IV therapeutic study.

IMAGING DIAGNOSIS—BILATERAL ABNORMAL OSSIFICATION OF THE SUPRAGLENOID TUBERCLE AND CRANIAL GLENOID CAVITY IN AN ENGLISH SETTER

An 8-month-old intact male English Setter was presented with bilateral shoulder lameness. Radiographic and CT examinations demonstrated bilateral irregular margination and separation of the supraglenoid tubercle from the scapula, with involvement of the cranial articular surface of the glenoid cavity. After 30 days of cage rest, complete fusion of proximal portions of both supraglenoid tubercles and persistent un-united cranial portions of both glenoid cavities were evident. Histopathologic findings from biopsies of glenoid cavity defects were consistent with osteochondrosis or focal chondrodysplasia.

Parathyroid Hormone Applications in the Craniofacial Skeleton

Parathyroid hormone (PTH) is known for its ability to ‘build’ bone, with research in this area centered on its use as an osteoporosis therapeutic. Recent interest has developed regarding its potential for regenerative applications such as fracture healing and osseous defects of the oral cavity. Many years of investigation using murine gene-targeted models substantiate a role for signaling at the PTH/PTH-related protein (PTHrP) receptor (PPR) in intramembranous bone formation in the craniofacial region as well as in tooth development. Pre-clinical studies clearly support a positive role of intermittent PTH administration in craniofacial bones and in fracture healing and implant integration. A few human clinical studies have shown favorable responses with teriparatide (the biologically active fragment of PTH) administration. Favorable outcomes have emerged with teriparatide administration in patients with osteonecrosis of the jaw (ONJ). New delivery strategies are in development to optimize targeted application of PTH and to help maximize local approaches. The promising host-modulating potential of PTH requires more information to further its effectiveness for craniofacial regeneration and osseous wound-healing, including a better delineation of cellular targets, temporal effects of PTH action, and improved approaches for local/targeted delivery of PTH.

Study on the Cavity Defects of Low-Pressure Lost Foam Casting for Magnesium Alloy

Cavity defects of low-pressure lost foam casting (LP-LFC) for magnesium alloy were investigated by using ladder samples and claviform samples.The physical feature of typical cavity defects of LP-LFC for magnesium castings had been tested by optical microscopy and scanning electron microscopy. And the chemical constitution of cavity surface was also tseted by energy spectrometer. The result indicated that the cluster cavity defects were formed with the application of higher vacuum at the metal-mold interface, which caused the liquid-EPS residue in the castings. Some irregular shape cavity defects were caused by slag entrapment or coating slough. These cavity defects could be avoided through reducing pouring temperature, filling velocity and vacuum level, improving the permeability of coating.

Infrahyoid Myocutaneous Flap for Medium‐Sized Head and Neck Defects

To evaluate the surgical outcomes associated with infrahyoid myocutaneous flaps used in the reconstruction of medium-sized defects following head and neck cancer resection, as well as to discuss a novel technique modification. Case series with chart review. University cancer hospital. A total of 20 patients with oral or hypopharyngeal carcinoma who underwent infrahyoid myocutaneous flap reconstruction between June 2005 and December 2011 were retrospectively studied. A novel technical modification of flap harvest, preservation of the cranial portion of the anterior jugular vein, was attempted in 15 flaps and was successful in 13 flaps. Functional evaluation was performed in all patients 3 to 6 months after the operation or postoperative radiation. Total flap necrosis, marginal skin paddle necrosis, and total skin paddle loss were observed in 1, 2, and 1 patient(s), respectively. Pharyngocutaneous fistula without flap problem occurred in 1 patient. No flap complications occurred in 13 cases where the cranial portion of the anterior jugular vein was successfully preserved. Functional results were excellent in 16 patients, good in 3 patients, and fair in 1 patient. The infrahyoid myocutaneous flap is a reliable and convenient technique that can serve as an alternative to free flaps in the reconstruction of medium-sized defects of the oral cavity or hypopharynx. Preservation of the cranial portion of the anterior jugular vein is a novel technical modification of harvesting this flap, which may result in better venous return of the skin paddle and reduce skin paddle necrosis.

Surgical strategies based on standard templates for microsurgical reconstruction of oral cavity and oropharynx soft tissue: A 20 years' experience

Microsurgical reconstruction has become the worldwide gold standard for repairing surgical defects in head and neck cancer. The aim of this article is to describe a standardized reconstructive approach to the oral cavity and oropharynx soft tissue defects. Since 1992, the authors have treated 163 patients affected by oral cavity and oropharynx cancer, performing a total of 175 flaps. A systematic postoperative functional study prompted a surgical strategy, in terms of flap choice, shape, and insetting. A two-dimensional template was used to obtain a three-dimensional reconstruction for the best functional and aesthetic outcome. To simplify preoperative planning, surgical resections were divided into a set number of classes. The templates, flap choice, and insetting are described for each region. Complications consisted of seven partial necroses of the flap which easily resolved with a local toilette and 12 complete necroses of the flap due to vascular thrombosis, these patients required a secondary reconstruction with another free flap. Functional results were systematically evaluated in the first 60 patients of our series with particular attention to the swallowing function, which was analyzed by both videofluoroscopy and functional endoscopic evaluation of swallowing. Results showed a good functional recovery with the described reconstructive techniques. A standardized surgical strategy based on reproducible templates might facilitate less experienced surgeons in analyzing the problem, choosing the best technical solution and foreseeing the functional outcomes.

Design of tool system for the external nonrotational shoulder assisted friction stir welding and its experimental validations on 2219-T6 aluminum alloy

The nonrotational shoulder assisted friction stir welding (NRSA-FSW) is still in the feasibility study stage. To reveal details in the tool system designing and highlight advantages of this novel technology, the tool system for the NRSA-FSW was designed and utilized to weld high-strength aluminum alloy 2219-T6 for validations. Compared with the joints welded by the friction stir welding (FSW) without assistance of the nonrotational shoulder (NRS), the effect of the NRS on the weld formation and mechanical properties was illustrated. At a constant welding speed 100 mm/min, defect-free joints can only be obtained at the tool rotation speed 800 rpm by the FSW without assistance of the NRS, but the NRSA-FSW can produce defect-free joints in a wider range of tool rotation speeds 600–900 rpm. The NRS prevented all plasticized materials from escaping from the stirring zone, thus the weld nugget zone transformed from the basin-type formation to the spherical formation with increasing of the stirring effect when the tool rotation speed increased gradually. For joints welded by these two FSW processes, both the tensile strength and the elongation showed nearly the same trend with the tool rotation speed, but the NRSA-FSW can produce joints with the maximum tensile strength in a wider range. Compared with the maximum joint efficiency 71.2 % of the FSW without assistance of the NRS, the maximum tensile strength obtained by the NRSA-FSW also reached 69.0 % of the base material. All tensile specimens machined from defect-free joints fractured at the weakest region with minimum Vicker’s hardness; while for those joints with cavity defects, the fracture occurred at the defect location.

Effects of tool rotation speed on microstructures and mechanical properties of AA2219-T6 welded by the external non-rotational shoulder assisted friction stir welding

The external non-rotational shoulder assisted friction stir welding (NRSA-FSW) was applied to weld high strength aluminum alloy 2219-T6 successfully, and effects of the tool rotation speed on microstructures and mechanical properties were investigated in detail. Defect-free joints were obtained in a wide range of tool rotation speeds from 600rpm to 900rpm, but cavity defects appeared on the advancing side when the tool rotation speed increased to 1000rpm. The microstructural deformation and heat generation were dominated by the rotating tool pin and sub-size concave shoulder, while the non-rotational shoulder helped to improve the weld formation. Microstructures and Vickers hardness distributions showed that the NRSA-FSW is beneficial to improving the asymmetry and inhomogeneity, especially in the weld nugget zone (WNZ). At the tool rotation speed of 800rpm, both the tensile strength and the elongation reached the maximum, and the maximum tensile strength was up to 69.0% of the base material. All defect-free joints were fractured at the weakest region with minimum Vickers hardness in the WNZ, while for the joint with cavity defects the fracture occurred at the defect location.

Modelling of shrinkage cavity defects during the wheel and belt casting process

Properzi continuous casting is a wheel and belt casting process used for producing aluminium wire rod which is essential to the making of electrical cables and over head lines. One of the main concerns of Properzi process users is to ensure good quality of the final product and to avoid cast defects especially the presence of shrinkage cavity. Numerical models developed with the Alsim software, which allows an automatic calculation of gap dependent heat transfer coefficients at the metal-mould interface due to thermal deformation, are used in order to get a better understanding on the shrinkage cavity formation. Models show the effect of process parameters on the cavity defect development and provide initial guidance for users in order to avoid this kind of casting defect.

Do Dynamic Cement-on-Cement Knee Spacers Provide Better Function and Activity During Two-stage Exchange?

Implantation of an antibiotic bone cement spacer is used to treat infection of a TKA. Dynamic spacers fashioned with cement-on-cement articulating surfaces potentially facilitate patient mobility and reduce bone loss as compared with their static counterparts, while consisting of a biomaterial not traditionally used for load-bearing articulations. However, their direct impact on patient mobility and wear damage while implanted remains poorly understood. We characterized patient activity, surface damage, and porous structure of dynamic cement-on-cement spacers. We collected 22 dynamic and 14 static knee antibiotic cement spacers at revision surgeries at times ranging from 0.5 to 13months from implantation. For these patients, we obtained demographic data and UCLA activity levels. We characterized surface damage using the Hood damage scoring method and used micro-CT analysis to observe the internal structure, cracking, and porosity of the cement. The average UCLA score was higher for patients with dynamic spacers than for patients with static spacers, with no differences in BMI or age. Burnishing was the only prevalent damage mode on all the bearing surfaces. Micro-CT analysis revealed the internal structure of the spacers was porous and highly inhomogeneous, including heterogeneous dispersion of radiopaque material and cavity defects. The average porosity was 8% (range, 1%-29%) and more than ½ of the spacers had pores greater than 1mm in diameter. Our observations suggest dynamic, cement-on-cement spacers allow for increased patient activity without catastrophic failure. Despite the antibiotic loading and internal structural inhomogeneity, burnishing was the only prevalent damage mode that could be consistently classified with no evidence of fracture or delamination. The porous structure of the spacers varied highly across the surfaces without influencing the material failure.

Risk Factors Associated With Repair of Orbital and Lateral Skull Defects

To explore the complications and associated risks factors after orbital exenteration and lateral skull base defect repair. Patients who had undergone a reconstruction of their orbital cavity and lateral skull base defects were selected from our departmental database. The outcome of interest was postoperative complications. The risks factors were defined as age, sex, history of radiation therapy, and intracranial involvement (with and without dural involvement). Information was collected on the type of reconstruction used after the orbital cavity repair. The χ2 test and logistic regression were used to analyze associations between postoperative complications and the various risks factors. Of the 32 identified patients, 19 had intracranial involvement (9 with dural involvement). Twenty-four patients underwent reconstruction with free tissue transfer in the same setting. Reconstruction with free tissue transfer was significantly associated with fewer major postoperative complications (P < .053). There was a trend toward more complications with a history of radiation therapy or intracranial involvement. Reconstruction of the orbital cavity and lateral skull base can be challenging, especially if there is a history of radiation therapy and intracranial involvement. Free tissue transfer is a safe and effective method for reconstruction of such defects.

Use of Nasolabial Flap in Intra and Extraoral Reconstruction: Our Experience with 40 Cases

This article represents the use of inferiorly based nasolabial flap in reconstruction of various intraoral and extraoral defects. Nasolabial flaps were performed in 40 patients, for reconstruction of buccal mucosa, gingivobuccal sulcus, commissure, lower lip, floor of mouth, upper lip and lower alveolar defects. The most common defect site in the oral cavity was the buccal mucosa. Partial flap necrosis occurred in five patients. Out of 40 cases of carcinoma of lip, commissure and floor of the mouth, all the patients had good speech after complete healing of the wound. None of the patients who had lip or commissure reconstruction developed drooling of saliva due to lip incompetence. The inferiorly based nasolabial flap provides reliable coverage of intermediate-sized oral cavity defects when used alone. Minimal donor morbidity is associated with its use. It is especially useful in elderly patients with facial skin laxity and where esthetics is not a major concern.

Expression of leukemia inhibitory factor in the endometrium in abnormal uterine cavities during the implantation window

To investigate the expression of the implantation factors leukemia inhibitory factor (LIF), interleukin-11 (IL-11), and IL-6ST/gp130 in the endometrium to examine the relationship between loss of implantation and abnormal uterine cavity. Case-control study. Department of Obstetrics and Gynecology, Tokyo Medical University. Subjects comprised 41 patients in the abnormal uterine cavity group who underwent resection of a uterine submucosal myoma or an endometrial polyp by transcervical resectoscopy (TCR) and 18 patients in the control group who underwent laparoscopic surgery. In the abnormal uterine cavity group, endometrial tissue specimens were obtained before resection under hysteroscopy. In the control group, endometrial tissue specimens were obtained by curettage at the time of laparoscopic surgery. We divided the patients into four groups according to menstrual cycle and measured the endometrial expression of LIF, IL-11, and IL-6ST/gp130 with the use of quantitative real-time reverse-transcription polymerase chain reaction. Significant increases in LIF and IL-11 mRNA expression were recognized during the midsecretory phase of the menstrual cycle in the control group. However, no difference in IL-6ST/gp130 mRNA expression was observed in any phase during the menstrual cycle in either group. In terms of LIF and IL-11 mRNA expression at the midsecretory phase, the abnormal uterine cavity group showed a significantly decreased LIF mRNA expression compared with the control group. LIF mRNA expression was significantly decreased in abnormal uterine cavities during the midsecretory phase, indicating that endometrial cavity defects are a possible cause of poor reproductive outcomes.