When the free TRAM flap was introduced for breast reconstruction, it was supposed to have many advantages over the pedicled TRAM flap: good perfusion of all four zones, better mobility and easier ...shaping of the breast, lower incidence of abdominal-wall complications, and less restrictive selection of patients. However, we have experienced several complications after free TRAM flaps in our practice, including fat necrosis, partial and complete flap necrosis, abdominal-wall weakness, and hernias. In order to evaluate the incidence and types of complications, as well as the influence of preoperative risk factors (chemotherapy, radiotherapy, overweight, smoking habits, and abdominal scars), on complications, a multicentric prospective study including Bern (Switzerland), Leuven (Belgium), Stuttgart (Germany), and Verona (Italy) was designed. In 111 consecutive patients, operated on over a period of 18 months, 123 flaps were done; 99 flaps were unilateral and 24 bilateral, and 36 were used for primary and 87 for late reconstruction. There was no preoperative selection of patients. The follow-up period was from 8 to 24 months (average 19 months). A two-team operating approach was used. All four zones were always included in the flap, and the end-to-end anastomoses were done to the thoracodorsal, the circumflex scapular, or the internal mammary arteries. The total number of fat and flap necroses was 24 (19.5 percent), 6 (5 percent) minor and 4 (3 percent) major fat necroses, 2 (1.6 percent) minor and 6 (5 percent) major flap necroses, and 6 (5 percent) total flap necroses. Twenty-two (20 percent) patients had abdominal-wall complications. The results of this study show that the complication rate of free TRAM flaps is considerable. Preoperative risk factors did not play a major role in the development of complications and should not be considered as contraindications for free TRAM flap surgery. All total flap failures resulted from impaired arterial inflow to the flap, and the choice of recipient vessel did not influence the outcome. The incidence of total flap failures might be reduced by good postoperative flap monitoring and early revision of the anastomosis. Partial fat and flap necroses might be prevented by removing the fat under the scarpa fascia in zones 4 and 3 or by reducing zone 4. Sparingly harvesting the rectus muscle and its sheath as well as the use of mesh in the rectus sheath repair may reduce the abdominal-wall complications.
A retrospective study was undertaken to evaluate the long-term results of reduction mammaplasties. Of special interest was the extent to which the amount of breast tissue removed correlated with pain ...relief after reduction mammaplasty. One hundred fourteen patients underwent an average reduction of 1,266 g. The follow-up time was 7.7 years. Ninety-one percent of the patients noticed a decrease in shoulder, neck, and back pain, and lessening of brassiere shoulder grooves. Nine percent noticed no change at all, and only 1 patient complained of increased breast pain after the operation. In 11% of the patients, pain was not an indicator for the operation. We could find a significant correlation (r = 0.36, p = 0.001) between the amount of tissue resected and pain relief after surgery. The follow-up time did not correlate with a regaining of the physical complaints (r = 0.15, p = 0.2). Patients gained an average of 1.2 kg and had an average preoperative overweight of 118%. From the results of our study we were able to conclude that an average reduction of 500 to 600 g of breast tissue on both sides has a long-lasting effect in reducing shoulder and back pain.
To evaluate the early and long-term results of the latissimus dorsi musculocutaneous flap for breast reconstruction, a series of 92 women who underwent surgery at my department from 1979 to 1989 was ...critically reviewed. Special attention was directed to the late foreign body reactions leading to deformation, asymmetry, and induration of the reconstructed breast. Guidelines regarding prevention of capsular contraction are discussed and some essential surgical refinements outlined.
Skin flaps are susceptible to ischemia, which may result in tissue necrosis particularly in areas deprived of their original anatomic blood supply. The pathophysiology of skin flap failure has been ...debated for many years, but due to methodological insufficiencies, every proposed theory has remained hypothetical. The aim of this study was to gain more evidence for the mechanisms involved in flap ischemia by assessing quantitatively hemodynamic parameters such as diameter, flow velocity, and volume flow in the microcirculation of a flap. To this end the authors developed a new island flap on the back of Syrian golden hamsters that allowed intravital microscopic investigation. The flap included an extended portion, which was deprived of its original anatomic blood supply. One hour after flap dissection, blood flow was 42% to 66% lower in all microvessels in the extended area than in the anatomically perfused part of the flap (p<0.05). In the entire microvasculature, a significant gradual decline of blood flow was observed over time. Any blood flow reduction was caused to a major extent by diminished flow velocity. At all times, microvascular diameters were slightly larger in the extended portion of the flap than in the anatomically perfused portion of the flap. The authors conclude that their new model is a unique tool for investigating microhemodynamic mechanisms involved in flap ischemia. This study reveals hypoperfusion of extended flap tissue, which is attributed to diminished arterial perfusion pressure but not to vasoconstriction or arteriovenous shunting.
The CPLEAR electromagnetic calorimeter Adler, R.; Backenstoss, G.; Bal, F. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
05/1997, Letnik:
390, Številka:
3
Journal Article
Recenzirano
Odprti dostop
A large-acceptance lead/gas sampling electromagnetic calorimeter (ECAL) was constructed for the CPLEAR experiment to detect photons from decays of π
0s with momentum
p
π
0 ≤ 800 MeV/
c. The main ...purpose of the ECAL is to determine the decay vertex of neutral-kaon decays K
0 → π
0π
0 → 4γ and K
0 → π
0π
0π
0 → 6γ. This requires a position-sensitive photon detector with high spatial granularity in
r−,
ϕ−, and
z−coordinates. The ECAL - a barrel without end-caps located inside a magnetic field of 0.44 T - consists of 18 identical concentric layers. Each layer of
1
3
radiation length (
X
0) contains a converter plate followed by small cross-section high-gain tubes of 2640 mm active length which are sandwiched by passive pick-up strip plates. The ECAL, with a total of 6
X
0 has an energy resolution of
α(E)
E
≈
13%
(E(
GeV)
and a position resolution of 4.5 mm for the shower foot. The shower topology allows separation of electrons from pions. The design, construction, read-out electronics, and performance of the detector are described.
The face lift procedure is often performed in aesthetic plastic surgery. It corrects the stigmata of age, i.e. the multiple facial wrinkles and the sagging of the atrophic soft tissues by undermining ...and retensioning the superficial and deeper facial and cervical structures. Since the public can not fully appreciate the extent and the inconveniences involved with this operation, emphasis must be laid on an exact preoperative information of the patient with regards to possible complications, the pros and cons of this procedure and the results to be expected. In this paper the face lift operation is explained in detail and the indications and contraindications given. The most frequent postoperative complications are outlined and the preventive measures and modalities of treatment discussed. From the medico-legal point of view it is important that such an operation is performed by a certified and well experienced plastic surgeon.
A follow-up study concerns about 120 eyes with an AC lens implanted between 5 and 11 years ago (mean: 6.75 years). Corneal edema is present in 6.5%, CME (reversible cases included) in 7.5%, secondary ...glaucoma only in 2%, and retinal detachment in 1%. Corneal edema, the main complication, is correlated with time and vitreous loss.
After unsuccessful ECCE, an AC lens should be implanted mainly in elderly patients, but seems still to be a true alternative.
The CPLEAR detector at CERN Adler, R.; Albrecht, W.; Alhalel, T. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
09/1996, Letnik:
379, Številka:
1
Journal Article
Recenzirano
Odprti dostop
The CPLEAR collaboration has constructed a detector at CERN for an extensive programme of CP-, T- and CPT-symmetry studies using K
0 and
K
0 produced by the annihilation of
p
's in a hydrogen gas ...target. The K
0 and
K
0 are identified by their companion products of the annihilation K
±
π
∓ which are tracked with multiwire proportional chambers, drift chambers and streamer tubes. Particle identification is carried out with a liquid Cherenkov detector for fast separation of pions and kaons and with scintillators which allow the measurement of time of flight and energy loss. Photons are measured with a lead/gas sampling electromagnetic calorimeter. The required antiproton annihilation modes are selected by fast online processors using the tracking chamber and particle identification information. All the detectors are mounted in a 0.44 T uniform field of an axial solenoid of diameter 2 m and length 3.6 m to form a magnetic spectrometer capable of full on-line reconstruction and selection of events. The design, operating parameters and performance of the subdetectors are described.
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