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PubMed2006

Complementary use of local excision and transanal endoscopic microsurgery for rectal cancer after neoadjuvant chemoradiation.

BACKGROUND: Neoadjuvant therapies have significantly improved local control and survival of patients with rectal cancer. Nevertheless, although a complete pathologic response can be achieved in 30% of cases, a transabdominal surgical resection is always required. This study aimed, for the first time, to test in the literature the feasibility of local excision combined with transanal endoscopic microsurgery (TEM) as a surgical option for patients treated with neoadjuvant chemoradiation. METHODS: Between July 1997 and December 2002, 30 patients with rectal cancer affected by an extraperitoneal tumor entered a protocol consisting of neoadjuvant chemoradiation followed by surgery. The surgical treatment, consisting of open surgery, local excision, or TEM, was planned according to the patient's clinical response after chemoradiation and distance from the anal verge. RESULTS: A significant clinical downstaging was observed in eight patients. Five of these patients underwent TEM, and three had local excision. Consequently, open surgery was performed for 22 patients. Histology showed six cases of complete pathologic response: three in the open surgery group and three in the transanal excision group. After a mean follow-up period of 47 months, the disease-free survival rate was 77% in the open surgery group and 100% in TEM or local excision group. CONCLUSIONS: The findings suggest the complementary feasibility of TEM and local excision after neoadjuvant chemoradiation. However, randomized trials are needed to confirm the oncologic safety of this approach.

Aged↗

PubMed2005

Operative strategies in aortic graft infections: is complete graft excision always necessary?

The classic approach to aortic graft infections involves complete excision of the graft material with remote reconstruction of the distal circulation. Certain patients may not be well suited for this approach for physiologic or anatomic reasons. This study was undertaken to determine the outcome of partial graft excision in selected patients with aortic graft infection who were not felt to be candidates for complete graft excision. Retrospective analysis of 30 consecutive patients treated with infected grafts arising from the aorta over the past 10 years was performed. Mean interval between graft placement and infection was 5.5 years. Complete graft excision with bypass via clean tissue planes was achieved in 15 patients (group A), and partial or complete graft salvage or in situ graft replacement was performed at the discretion of the surgeon in 15 patients (group B). Perioperative mortality occurred in eight subjects (27%), including six in group A (40%) and two in group B (13%; p = NS). Six patients (20%) developed recurrent infection following graft excision, two (13%) in group A and four (27%) in group B (p = NS). Microorganisms were recovered from 24 of 30 (80%) graft cultures: 13 (43%) were gram positive, 4 (13%) were gram negative, and both gram-positive and gram-negative organisms were recovered from 7 (23%). Identification of culture isolates did not influence either perioperative mortality or the development of recurrent infection. Long-term survival was no different between the groups. We conclude that in certain high-risk patients who may not tolerate complete graft excision, local resection of infected graft segments may be preferable and leads to similar short- and long-term outcome.

Aged↗

PubMed2003

Definitive intraoperative radiotherapy for musculoskeletal sarcomas and malignant lymphoma in combination with surgical excision.

BACKGROUND: . The purpose was to estimate retrospectively the outcome of patients with musculoskeletal sarcoma or malignant lymphoma treated with intraoperative radiotherapy (IORT). METHODS: Between 1988 and 1999, definitive IORT in combination with surgical excision was performed in 24 patients with musculoskeletal sarcoma (malignant fibrous histiocytoma, 10; osteosarcoma, 6; liposarcoma, 2; chondrosarcoma, 1; synovial sarcoma, 1; Ewing's sarcoma, 1; angiosarcoma, 1; epithelioid sarcoma, 1; malignant schwannoma, 1) and 3 patients with malignant lymphoma. The tumor was excised by marginal margin excision, intralesional margin excision, or wide margin excision; 15-45 Gy electrons was then delivered to the affected sites. RESULTS: In the 8 patients without distant metastases at the first visit, 4 patients are alive 6.5-11.5 years after IORT, and 4 patients died <4.5 years after IORT. The incidence of local recurrence was 13%. In the 19 patients with distant metastases at the first visit, 3 patients are alive 2.5-6.7 years after IORT, and 16 patients died 0.2-5.7 years after IORT. The incidence of local recurrence was 45%. Complications after IORT were found in 5 patients: neuropathy, 1 patient; skin necrosis, 1 patient; myelopathy, 1 patient; enteritis ileus, 1 patient; and edema, 1 patient. CONCLUSION: IORT with a radiation dose of 15-45 Gy in combination with surgical excision appeared to be useful for local control and to be more effective in patients without distant metastases at the first visit than in patients with distant metastases.

Adolescent↗

PubMed2003

Local excision of large rectal villous adenomas: long-term results.

PURPOSE: Transanal excision of rectal villous adenomas is a widely used surgical technique, because it is a one-step procedure, requiring no sophisticated instrumentation, and allowing complete histologic analysis of the excised tumor. Therefore, it ranks alongside radical surgery and palliative destructive procedures, but its results are highly variable in the published series. This discrepancy may be explained by the variable completeness of tumor excision because of potential dissection difficulties. Because intraoperative exposure may be a major limiting factor, one of us (JF) has developed a tractable cutaneomucous flap procedure to lower the rectal tumor to the anal verge, where control of the dissection line is easier. This retrospective review of consecutive patients operated on during ten-year period reports long-term results after transanal excision for large rectal villous adenomas with the tractable flap technique. PATIENTS: From 1978 to 1988, 207 consecutive patients (100 males), mean age 68 (range, 24-90) years, were operated on for an apparently benign villous rectal adenoma. Twenty-one patients (10 percent) were referred after failure of previous treatments: 11 endoscopic, 8 surgical, 1 laser, 1 radiotherapy. Mean distance of lower tumor edge from anal margin was 5.6 (range, 0-13) cm and was <10 cm in 82 percent. RESULTS: Three patients (1.5 percent), including one with a Tis carcinoma, underwent a secondary treatment for immediate gross failure of resection: one further local excision and two palliative laser destructions. Immediate postoperative course was uneventful for 96 percent; there was one death from perineal gangrenous infection, four cases of hemorrhage, and three urinary retentions. Subsequently one case of transient fecal incontinence and 11 medically managed stenoses were noted. Mean size of resected tumor was 5.4 (range, 1-17) cm. Deep excision margins concerned the rectal muscular layers in 199 patients (96 percent) and perirectal fat in 8 (4 percent). Specimen margins were negative for cancer in 175 (85 percent) and positive or unknown in 32 cases. Histologic evaluation demonstrated in situ cancer in 28 (14 percent) and invasive carcinoma in 9 (4 percent). In three patients (1 percent), two abdominoperineal resections were immediately performed (one T2 with a mucinous contingent, one T3) and one adjuvant radiotherapy (one undifferentiated T2). Four patients (2 percent) did not return for postoperative evaluation. For the remaining 198 patients, mean follow-up was 74 +/- 34 (median, 75; range, 1-168) months. Forty-four died from unrelated causes. Recurrence occurred in seven (3.6 percent) and was malignant in two, who subsequently died. Specific recurrence-free probability was 99.5 percent at one year, 96 percent at five years, and 95 percent at ten years. A lesion size >6 cm (10 vs. 1 percent for smaller tumors) and the presence of an invasive carcinoma (20 vs. 3 percent without invasive carcinoma) were significantly associated with an increased probability of recurrence at five years. CONCLUSION: Providing that adequate intraoperative exposure is obtained and advanced malignant tumors receive immediate secondary treatment, transanal resection of clinically benign, large rectal villous adenomas is safe and effective. It is an alternative to rectal resection, which exposes the patient to potentially adverse effects, and also to destructive procedures, which preclude any histologic evaluation of the tumor.

Adenoma, Villous↗

PubMed1999

Sentinel node biopsy before and after wide excision of the primary melanoma.

BACKGROUND: Initially, the technique of sentinel node biopsy involved the use of blue dye alone and was later supplemented with the use of an intraoperative probe after radiocolloid injection near the melanoma site. Ideally, it should be done before wide excision. To our knowledge, there is no information in the literature regarding the applicability or reliability of this technique after wide excision. METHODS: We conducted a retrospective review of 142 patients (1993-1999) with melanomas > or =1.0 mm or Clark's level > or =IV. Of these, 116 patients had prior biopsy only, and 26 had wide excision. The mean melanoma thickness was 2.5 mm. The location of the primary lesion was in the upper extremity in 42 patients, the lower extremity in 33, the trunk in 49, and the head and neck area in 18. RESULTS: The sentinel node was identified in 88 (93%) of 95 nodal basins using the blue dye alone and in 65 (98.5%) of 66 basins using dye plus probe. The sentinel node was positive in 35 (25%) of the 142 patients and 38 (24%) of the 161 nodal basins. In a mean follow-up of 30 months of 115 basins with negative sentinel nodes, 3 (3%) later developed a palpable positive node in the same basin. In the group of dye alone, the sentinel node was identified in 40 (100%) of 40 extremity primaries and in 48 (87%) of 55 trunk and head and neck primary lesions (P = .02). Nine (35%) of the 26 patients with previous wide excision (25 with primary closure or skin graft, 1 with flap rotation) and 10 (32%) of 31 of nodal basins had a positive node; in 8 of the 9 patients, the positive node was also the sentinel node. The only patient with a positive node incidentally removed along with a histologically negative sentinel node was the one with a previous wide excision and flap rotation. CONCLUSIONS: Previous wide excision of the melanoma does not appear to negate the reliability of sentinel node biopsy, provided that no flap rotation was used to cover the defect.

Biopsy↗

PubMed1986

A new concept of the anatomy of the anal sphincter mechanism and the physiology of defecation. Reversion to normal defecation after combined excision operation and end colostomy for rectal cancer.

Twenty-one patients with combined excision operation for rectal cancer were subjected to electromyographic study of the levator ani muscle, the puborectalis muscle, and the external anal sphincter. Myoelectric activity of the puborectalis and levator ani muscles was detected in 12 patients, 6 of whom had normal activity of both muscles. Of the remaining six patients, there was reduced activity of the levator ani muscle in four and of the puborectalis muscle in all six. These patients underwent training and electric stimulation of these muscles. To verify the myoelectric findings, 15 specimens removed at combined excision operation were examined grossly and microscopically for the muscles removed at operation. Eight specimens were found to be free of the levator and puborectalis muscles, which indicated that these muscles were not excised. The 12 patients with myoelectrically active levator and puborectalis muscles were operated on to restore defecation by way of the normal perineal route. The technique comprises freeing of the colostomy and mobilization of the entire left side of the colon. The perineal scar is then excised and the colonic end fixed to the perineal skin and thus is controlled by the levator and puborectalis muscles. Full fecal control was achieved in seven patients and incomplete control in five. It is concluded that excision of the levator ani muscle, the puborectalis muscle, and the external anal sphincter should not be considered a standard part of the radical operation for cancer of the lower or middle third of the rectum, and that a combined excision operation has no place in the treatment of rectal cancer.

Adult↗

PubMed1993

Excision of benign pigmented skin tumours by deep shaving.

Benign pigmented skin tumours are frequently removed by shave excision. There is little information as to how often the method achieves a complete excision of the lesion and how often the full thickness of the dermis is removed. 43 benign pigmented skin tumours, on the trunk and proximal parts of the limbs, were removed by deep shaving and the shaved areas were then removed by elliptical excision. The shave excision achieved complete tumour removal in 72% of the lesions and did not divide the dermis to fat junction in 63%. Both objectives were achieved in 46%. Shave excision of these lesions may be preferable to elliptical excision in sites where the incidence of hypertrophic scarring is high, as preservation of some thickness of the dermis may result in a more acceptable scar.

Adolescent↗

PubMed1975

A mutant of Eshcerchia coli K-12, URT-43, with a temperature-sensitive defect at the incision step of the excision repair mechanism.

URT-43, which has a defect in excision repair, exhibits a temperature-dependent ultraviolet survival. It was shown that URT-43 requires protein synthesis but not DNA synthesis for recovery, by examining recovery in a growth medium containing chloramphenicol or nalidixic acid. The recovery of irradiated bacteriophage lambda in URT-43 took place in a medium containing nalidixic acid at 30 degrees, but not at 41 degrees, and chloramphenicol prevented this recovery. These results seem to imply that the product of the mutated gene in URT-43 is labile. URT-43 was confirmed to have a temperature-sensitive mutation at the incision step of the excision repair mechanism by examining the nick formation of parental DNA in alkaline sucrose gradients. The release of pyrimidine dimers was reinvestigated directly by one- and two-dimensional paper-chromatography and indirectly by examining the distribution of DNA molecules synthesized after irradiation. Dimers were excised into the acid-soluble fraction when growing bacteria were incubated, but were not excised when in amino acid starved bacteria. These results suggest that URT-43 is a mutant slowly excising pyrimidine dimers because the product of a mutated gene concerned with the incision step of the excision repair mechanism is unstable.

Centrifugation, Zonal↗

PubMed1979

DNA excision-repair processes in human cells can eliminate the cytotoxic and mutagenic consequences of ultraviolet irradiation.

The ability of DNA excision-repair processes in diploid human fibroblasts to eliminate potentially cytotoxic and mutagenic lesions induced by UV radiation (254 nm) was demonstrated in two ways: (1) Cells with normal rates of excision were compared with cells with an intermediate rate of excision (XP2BE) and cells with an excision rate less than or equal to 1% that of normal (XP12BE) for sensitivity to the killing and mutagenic action of UV radiation. The normal cells proved resistant to doses of UV which reduced the survival of the XP cells to 14% and 0.7%, respectively, and increased the frequency of mutations to 8-azaguanine resistance in the XP cells 5- to 10-fold over background. (2) Cells in confluence were irradiated with cytotoxic and mutagenic doses of UV and allowed to carry out excision repair. After various lengths of time they were replated at lower densities to allow for expression of mutations to 6-thioguanine resistance and/or at cloning densities to assay survival. Normal cells and XP cells with reduced rates of excision repair (from complementation groups C and D) exhibited a gradual increase in survival from an initial level of 15--20% to 100% if held approximately 20 h in confluence. In contrast, XP12BE cells showed no increase from an initial survival of 20% even when held for 7 days. Normal cells irradiated in confluence but prevented from replicating for 7 days exhibited background mutation frequencies, whereas the mutation frequency in XP12BE cells did not change with the time in confluence.

Cell Line↗

PubMed1989

Modulation of mutagenesis involving precise excision of transposon Tn10.

Precise excision of transposon Tn10 results in reversion of the Trp- phenotype to Trp+ in a trp-1014::Tn10 strain of Salmonella typhimurium, and also occurs at a markedly higher frequency in a strain carrying the temperature-sensitive polA7 allele. The frequency with which precise excision events occurs can be modified by the plating medium, results indicating that the great majority of mutants which arise on broth-supplemented or tryptophan-supplemented minimal media actually arise on the selective plating medium. Trp+ revertants (1000) arising from excision of Tn10 were purified by re-streaking for single colonies; none were found to retain the Tn10 encoded resistance to tetracycline. Yields of Trp+ revertants of the polA7 strain were consistently higher when glycerol rather than glucose was used as sole carbon source in the selective medium. Clean excision of Tn10 can also be increased by ultraviolet irradiation in (R) plasmid-free strains, and is further increased in strains carrying an N-group plasmid (R205, R46 or pKM101). Ultraviolet-induced precise excision of Tn10 also occurs at a much enhanced frequency in a strain with a deletion through the uvrB gene; in this case, however, the addition of plasmid pKM101 leads to a decrease in yields of ultraviolet-induced precise excision events.

Chromosome Deletion↗

PubMed1992

Mutagenic DNA repair in Escherichia coli. XXI. A stable SOS-inducing signal persisting after excision repair of ultraviolet damage.

Mutations to streptomycin resistance induced by ultraviolet light in Escherichia coli can lose their susceptibility to photoreversing light during excision repair and in the absence of chromosomal replication and protein synthesis, i.e., under conditions where SOS induction cannot occur. Using fusions of lac with sulA and umuC we have shown that after excision of UV damage in the presence of chloramphenicol there is a persisting, relatively stable signal capable of inducing SOS genes when protein synthesis is subsequently permitted. The persisting signal is formed roughly in proportion to the square of the UV dose and is about 30% photoreversible. It is suggested that the persisting SOS-inducing signal comprises a UV photoproduct (the target lesion) opposite a gap in the opposing DNA strand, and is formed by excision of one (the ancillary lesion) of a pair of closely opposed photoproducts. Calculations suggest that as few as two or three such configurations in a cell can lead to induction of sulA when protein synthesis is permitted. It is not clear whether these configurations can directly induce the SOS system because of their region of single-stranded DNA or whether the ultimate SOS-inducing signal is a more extensive single-stranded region formed when such configurations encounter a replication fork. Photoproduct/gap configurations have been previously suggested to be potentially mutagenic. UV-induced mutations to streptomycin resistance are mostly at A:T sites and are not photoreversible in fully SOS-induced bacteria in the absence of excision repair, indicating that they are not targeted at cyclobutane-type pyrimidine dimers. In SOS-induced excision-proficient bacteria there is about 39% photoreversibility which is rapidly lost after UV. This photoreversibility is attributed to many ancillary lesions being cyclobutane-type pyrimidine dimers which are excised leading to the exposure of target lesions on the opposing strand which, at these particular sites, are mostly non-photoreversible photoproducts.

Bacterial Proteins↗

PubMed1981

In vitro splicing of the ribosomal RNA precursor of Tetrahymena: involvement of a guanosine nucleotide in the excision of the intervening sequence.

In previous studies of transcription and splicing of the ribosomal RNA precursor in isolated Tetrahymena nuclei, we found that the intervening sequence (IVS) was excised as a unique linear RNA molecule and was subsequently cyclized. In the present work, transcription at low monovalent cation concentration is found to inhibit splicing and to lead to the accumulation of a splicing intermediate. This intermediate contains splicing activity that either is tightly bound to the RNA or is part of the RNA molecule itself. The intermediate is able to complete the excision of the IVS when it is incubated with a monovalent cation (75 mM (NH4)2SO4), a divalent cation (5-10 mM MgCl2) and a guanosine compound (1 microM GTP, GDP, GMP or guanosine). ATP, UTP, CTP and guanosine compounds without 2' and 3' hydroxyl groups are inactive in causing excision of the IVS. Accurate excision of the IVS, cyclization of the IVS and (apparently) ligation of the 26S rRNA sequences bordering the IVS all take place under these conditions, suggesting that a single activity is responsible for all three reactions. During excision of the IVS, the 3' hydroxyl of the guanosine moiety becomes linked to the 5' end of the IVS RNA via a normal phosphodiester bond. When GTP is used to drive the reaction, it is added intact without hydrolysis. Based on these results, we propose that Tetrahymena pre-rRNA splicing occurs by a phosphoester transferase mechanism. According to this model, the guanosine cofactor provides the free 3' hydroxyl necessary to initiate a series of three transfers that results in splicing of the pre-rRNA and cyclization of the excised IVS.

Animals↗

PubMed1992

Precise excision of transposons and point mutations induced by chemicals.

The ability of 23 chemicals (carcinogens and non-carcinogens) to induce precise excision of Tn10 and point mutations was studied in experiments with a single strain. The mutation assay was shown to detect a wider spectrum of genotoxic agents than the assay of Tn10 precise excision. The latter was induced only by potent SOS mutagens, which is in accordance with data on the SOS dependence of the induction of precise excision of Tn10. The precise excision assay as an additional test contributing to the knowledge of particular features of the action of a tested mutagen is discussed. The induction of precise excision of Tn10 by pyrene (and its failure to induce point mutations in this strain) demonstrates the value of using the transposon excision assay in cases of 'problem' mutagens.

Carcinogenicity Tests↗

PubMed1983

Lack of effect of hydroxyurea on base excision repair in mammalian cells.

The effect of hydroxyurea on the initial steps of base excision repair has been examined in mammalian cells in 3 different proliferative states: i.e., quiescent cells, asynchronously growing cells undergoing multiple divisions prior to confluence; and synchronous cell populations undergoing the first cell cycle(s) after release from quiescence. Two parameters of the base excision repair pathway were examined: (1) The direct excision of 7-methylguanine from cellular DNA in the presence of increasing hydroxyurea concentrations was quantitated by high performance liquid chromatography; (2) the effects of hydroxyurea on the uracil DNA glycosylase were examined by quantitating the levels of this base excision repair enzyme in quiescent and proliferating cells. In quiescent cells, hydroxyurea at concentrations routinely used to quantitate DNA repair had no effect on the excision rates of 7-methylguanine examined over a span of 3 days; nor was there any effect on the specific activity of uracil DNA glycosylase in confluent cells. In asynchronously proliferating mammalian cells, identical hydroxyurea concentrations had no effect on the induction of the glycosylase. In synchronous growing cells HU had no effect on the temporal sequence of induction of uracil DNA glycosylase prior to DNA replication, nor on the extent of this induction. These results suggest that hydroxyurea at concentrations generally used to measure DNA repair has no effect on base excision repair.

Animals↗

PubMed1985

Excision repair of UV- or benzo[a]pyrene diol epoxide-induced lesions in xeroderma pigmentosum variant cells is 'error free'.

It is known that cells from one class of xeroderma pigmentosum (XP) patients, called XP variants, carry out excision repair of UV-induced DNA damage at a normal rate and are only slightly more sensitive than normal cells to the cytotoxic effect of UV radiation, but are much more sensitive to the mutagenic effect of UV. To see if this hypermutability were the result of an 'error-prone', excision repair process, we irradiated fibroblasts derived from an XP variant patient, XP4BE, under conditions that allowed the cells various lengths of time for excision repair before the onset of DNA synthesis (S phase) and assayed the frequency of 6-thioguanine (TG)-resistant mutants. Cells synchronized by release from confluence (G0 state) and irradiated just prior to S phase showed a dose-dependent increase in mutants at very high frequencies; cells irradiated in early G1, approximately 12 h before the onset of S phase, showed frequencies 4 times lower. Cells irradiated in the G0 state and allowed 24 h or 48 h for excision repair before the onset of S phase showed still lower frequencies. A comparison of the relative rates of decrease in mutant frequency with time for excision repair before the onset of S phase in XP variant cells and normal human fibroblasts after a dose of 4 or 6 J/m2 showed that these were equal. However, for every time point, the frequency of mutants induced per dose of UV was significantly higher in the XP variant population than in the normal, suggesting that the XP variant cells have an abnormally error-prone process of replicating DNA on a template containing unexcised lesions or normal cells are by-passing many of such lesions using an error-free process. A similar comparative study in synchronized populations of XP4BE cells and normal cells, using the anti 7,8-diol-9,10-epoxide of benzo[a]pyrene, showed that excision repair prior to the onset of S phase also decreased the frequency of mutants induced in XP variant cells by this agent. But for every dose and time point, the frequencies induced in XP4BE cells and normal cells were identical. Thus, the hypermutability of the XP4BE cells was specific to UV radiation-induced DNA lesions.

7,8-Dihydro-7,8-dihydroxybenzo(a)pyrene 9,10-oxide↗

PubMed1988

UV mutagenesis in E. coli with excision repair initiated by uvrABC or denV gene products.

Mutation frequency responses produced by ultraviolet light are compared in 4 closely related strains of E. coli B/r having the same tyr(Oc) allele and different excision-repair capabilities: uvr+ (excision repair initiated by wild-type UvrABC activity), uvrA (excision repair defective), uvrA/pdenV-7 (excision repair initiated by endonuclease V of bacteriophage T4, DenV activity), and uvr+/pdenV-7 (excision repair initiated by UvrABC and DenV activities). The production of Tyr+ prototrophic mutants is classified into back-mutations and de novo or converted glutamine tRNA suppressor mutations to indicate different mutation events. Cells transformed with the plasmid pdenV-7 require larger exposures than the parent strains to produce comparable mutation frequency responses, indicating that DenV activity can repair mutagenic photoproducts. When damage reduction by UvrABC or DenV is compared for each of the specific categories of mutation, the results are consistent with the idea that pyrimidine dimers infrequently or never target back-mutations of this allele, frequently target the de novo suppressor mutations, and extensively or exclusively target the converted suppressor mutations. This analysis is based on the distinction that UvrABC-initiated excision repair recognizes dimer and non-dimer (pyrimidine (6-4) pyrimidone) photoproducts but that DenV-initiated repair recognizes only pyrimidine dimers.

Cloning, Molecular↗

PubMed1995

Acne keloidalis nuchae: treatment with excision and second-intention healing.

BACKGROUND: Acne keloidalis nuchae (AKN) is a chronic inflammatory disorder of the posterior aspect of the neck and occipital region of the scalp. Despite numerous medical and surgical treatment modalities, few offer cure or a superior cosmetic result for patients with extensive disease. OBJECTIVE: Our purpose was to determine whether excision with second-intention healing is an effective therapeutic modality for AKN. METHODS: Excision of the involved area to the level of the muscle fascia or deep subcutaneous tissue was performed in six patients. Postoperative sites healed by second intention. RESULTS: Four of six patients had a horizontal elliptic excision of the involved area that included the posterior hairline, with good to excellent results. The other two, who received nonelliptic excision of affected scalp that spared the hairline, had slower wound healing and poor contraction. CONCLUSION: Best results were achieved in excision of AKN with second-intention healing when the excision was a horizontal ellipse of the posterior aspect of the scalp including the posterior hairline.

Acne Keloid↗

PubMed1983

Subjacent heat production during tissue excision with electrosurgery.

A study was designed to document heat production subjacent to tissue excision by electrosurgery. In Phase I of the study, 20 electrosurgery excisions were made with a loop electrode in the palatal mucosa of miniature swine. Subjacent heat production was measured with implantation thermistors. Temperature measurements adjacent to 20 single incisions made with a needle electrode were used for comparison. Energy used and duration of active electrode contact with the tissue were recorded for each procedure with an electronic measuring device. In Phase II, 20 sets of excisions consisting of three successive excisions were performed. The following intraexcisional cooling periods were used for four sets each: 1 second, 5 seconds, 8 seconds, 10 seconds, and 15 seconds. Results indicate that single electrosurgery excisions with a loop electrode generate more energy than incisions made with a needle electrode. Subjacent heat production, however, is not significantly different. Cooling intervals of at least 15 seconds between successive electrosurgery excisions made with a loop electrode are necessary to prevent heat build-up of a magnitude capable of initiating destructive alveolar changes.

Animals↗