if you have possibility to add at least one diagnostic method before making a decision to operate or now.

otherwise increase your sample size

It is a complex issue. As one gains experience the rate should dwindle drastically. Utilization of good imaging modalities will help keep the rate to a bare minimum.

I agree that it is a complex issue especially in resource limited settings where acute right iliac fossa pain is taken as an indication for appendicectomy due to lack of diagnostic facilities or even limited expertise in the use of diagnostic equipment.

I have also observed  that even an appendix that appeared normal when appendicectomy was performed after finding another abdominal pathology at exploratory laparotomy, histology results were that there were features of "appendicitis".

In some cases, radiology reports indicated "features acute appendicitis" and yet the appendix looks normal at surgery.

In my opinion therefore, all professionals involved in making a surgical diagnosis (surgeons, radiologists, pathologists etc. ) need to work as a team to reduce the negative appendicectomy rate. This is possible by establishing multidisciplinary surgical audit teams and conducting operational research aimed at continuous quality improvement.

My opinion is (as a surgeon that does around 70 appendectomies per year) that the problem about negative appendectomy rate is not so important.

1. We all know that significant percentage (some studies say even 70%) of female patients with chronic lower right abdominal pain do not have pain after elective appendectomy.

2. We are aware that small percentage of inflammation of appendix resolve during observational period in emergency room or during hospitalization. Some percentage of patients have up to several attacks of the same symptomatology in further life.

3. From my experience I operated on patients with clinical presentation of acute appendicitis that had the same symptoms previously with intraoperative findings of pericecal adhesions making somewhat more difficult operation.

4. You are aware that a small percentage of patients with typical clinical picture with peritoneal irritation have normal looking appendix during the operation. After the operation the pain is gone (not less intense but gone). Is that functional pain without pathologic evidence on specimen analysis.

4. Today with excellent (mini)laparoscopic equipment appendectomy is not the problem for operated patient in further life.

Don't get me wrong. Negative appendectomy rate should be less then 10%

In a world that even more speaks for Antibiotic VS surgery, we are debating about the right normal appendectomy rate? I think that if the antibiotic treatment for appendicitis will go on, in next future every appendectomy will be for a real appendicitis even with complication.

June 16, 2015, Vol 313, No. 23

Original Investigation | June 16, 2015

Antibiotic Therapy vs Appendectomy for Treatment of Uncomplicated Acute AppendicitisThe APPAC Randomized Clinical Trial

Dear Giorgio this is additional problem. If we say that negative appendectomy rate is 5-10%, or should be less then 5%. it means that 5-10% of patients will probably receive unneccessary antibiotic therapy.

Then the next question or problem arises. Is it better to perform appendectomy or to cure the same patient several times in several years with antibitics. What about the cost (not only antibiotics but complete diagnostic workup). What about development of resistant bacteria (ESBL + strains etc..).

 using sonographie as a diagnostic tool  can decrease the number of negative appendectomies. but less than 10% is very difficult to achieve

sonography is operator dependent and depends on the quality of the ultrasound machine itself. I saw several models that were unacceptable but used in some hospitals.

I completely agree with doctor Goran Augustin. A publication attach to support the position

A very provocative question! When I think back once taught us that it´s better to perform “white” appendectomy, than laparotomy for appendicular peritonitis. Now the imaging diagnostic plays a major role, but crucial for the diagnosis is the clinical examination and the personal experience. I study the literature and did not suspect that there are so serious studies about.

According M.Colson a.all  (1997,The AmJSurg,174,6,723) “A 10% to 20% negative appendectomy rate has been accepted in order to minimize the incidence of perforated appendicitis with its increased morbidity”.

In 2015 Papes a.all report that “The three largest series on pediatric appendectomy within the last two years are by Bachur that included 55,227 appendectomies (NAR 3.6%), Oyetunji that included 250,783 appendectomies (NAR 6.7%), and Cheong that included 78,625 children from US and 41,492 children from Canada (NAR 6.3 and 4.3%)”

There's something to think about, especially in the race for more new hospital patients.

http://www.karger.com/Article/FullText/380772

http://www.ingentaconnect.com/content/rcse/arcs/2012/00000094/00000006/art00004

http://pediatrics.aappublications.org/content/129/5/877.full.pdf

There is one thing that should be clarified. Negative appendectomy rate and perforated appendicitis are not connected as it was previously thought. Inflammatory type and obstructive type are practically two distinctive pathologies. That is why are specific groups of patients nowadays cured with antibiotics. But in obstructive type antibiotics would not prevent progression and perforation.

Well! I believe that each and every individual patient  with right lower quadrant or periumbilical pain should be studied on their own merits including age, sex,  clinical findings, concurrent diseases, hour of presentation, desire / consent of the patient, the level of consultant, status of the hospital and institution, investigation facilities available and many more. Judicious decisions must be made taking  all the  variables into consideration.  And then any NAR is acceptable.

I want to agree with all of you, however the discussion shows how difficult any figure for neg. appendectomy rates might be to be accepted generally.

We should not forget this by Goran Augustin neglected connection of NAR and perforation rates. It will be - how ever we do our diagnostics- always possible to extend the time to wait until a perforation occurs - we will have wonderful NAR´s going to zero! Therefore I would think the NAR has to be always connected to the rate of perforated appendices in the same collective to be significant.

Another main problem in all those studies is the quality of the pathohistological examination of the specimen. I know from several pathologies all over the world who do customize the result of their examination to the needs or wishes of the surgical dept. or the surgeons, particularly in private settings or if the bed occupancy rate is a criteria.

In large retrospective studies including different hospitals it will be very difficult to find a general and easy to use pathohistological definition of what is a non inflamed appendix.

What also is not determined up to now is that many of the patients we do treat - if surgically or conservative- will not be followed up by our own institution but by any other hospital and we never know if the same patient has been  treated e.g. surgically a month later somewhere else...for a late complication after appendectomy, or for appendectomy after prior conservative treatment.

Another problem is that some of us are experienced in ultrasound diagnostics with appendicitis, others have best experience by using CT-scan and modern low dose ct is available also during night, or MRI or combinations,  or others just rely on their clinical experience, there is no ultimate diagnostic tool and usage of it and also others do not have the choice or possibilities to perform more diagnostics or deny a surgical approach in cases of right abdominal pain. And not every removed specimen is sent to pathohistological evaluation!

Some of the surgeons don´t want to admit that the appendix was not inflamed, some are not experienced enough to differentiate and there is a wide field of subjective diagnosing.

As you see the uncertainties are so high that real significances are difficult to achieve. Thats the reason why I would agree with most of you but would also agree (at least for the time being) that NAR between 10 - 20% are acceptable if perforation rates at the same collective will not exceed 5-7%.

Dear Paya

I said 'Negative appendectomy rate and perforated appendicitis are not connected as it was previously thought'. previously the connection was direct. Today we not that it is connected but not as previously thought. And not every appendicitis will result in perforation. We are aware of cases with spontaneous resolution + cases treated with antibiotics

Accordingly to the literature an acceptable negative appendectomy is around 15%, and the complication rate of acute appendicitis (perforated appendicitis) is between 10-26%. In despite to the other question, clinical judge apparently is still the best way, although nowadays we have radiological (US or CT) images to help us with the diagnosis we as surgeon should not fall into fully depend on this method that are helpful when is a difficult case (old or very young patient). Here I leave you this title of an article for performance of diagnostic appendicitis scores: A new adult appendicitis score improves diagnostic accuracy of acute appendicitis - a prospective study  Sammalkorpi et al. BMC Gastroenterology 2014, 14:114

For paediatric patients managed in a tertiary centre with experienced Paediatric Surgery Team the negative appendectomy rate should be less than 2%. It just shows how clinical and radiological investigation have helped us tremendously the last 10 years. How do we strive to reduce the NAR from 4% to 2% without causing morbidity? Same clinical rules; regular assessment and ask for specific radiological signs suggestive of appendicitis. Never be satisfied with ultrasound findings of "appendix not well visualised". If a child with suspected appendicitis still has a tender right iliac fossa despite rehydration and analgesia but ultrasound showed compressible appendix-look for other causes; in Malaysia dengue infection mimics appendicitis.

Dear Dayang Anita Abdul Aziz - I appreciate your ambitious goal of just 2% of NAR! But the explanation how you want to achieve this does not convince me, just to rule out Dengue fever cannot be the clue, do you have any studies to prove this figures? 

We never had the chance to reach such good numbers without risk of accepting higher rates of overlooked appendicitis and complications due to late surgery. It would be great if you have found a way to nearly avoid any NAR- let us know how this works please.

Hi Prof Kurosh Paya. The figures are from our audit. Perhaps I didn't make it clear enough. In our unit, if a child comes in with probable acute appendicitis. We rule out the number one medical cause of RIF pain which is Dengue. The history, Haematocrit level and Dengue screening will help. I don't think we are different in the way we do clinical assessment and rehydration so I won't elaborate. We keep the child nil orally and antibiotics are not started unless perforated appendicitis is suspected, every child will get an ultrasound abdomen unless abdominal signs are too compelling. (Per rectal examination is important for assessment of pelvic appendicitis as RIF will be normal on examination and ultrasound) The only sign on ultrasound acceptable to exclude appendicitis is presence of compressible normal appendix. We do surgery when RIF is tender + usound shows distended appendix or faeces in appendix or free fluid at RIF. We also do surgery for patients with improved abdominal sign but usound showed distended appendix, faecolith in appendix. I guess the tricky part is for patients whom we continue to observe and challenge orally. We find those who tolerate orally not an issue anymore except in obese children. Obese children in our series do not have anorexia as a cardinal symptom of appendicitis. These are the ones we will subject them for CT Abdomen if ultrasound assessment is difficult. Patients who don't tolerate orally will go for repeat ultrasound 24 hours later and further clinical assessment. Changes if any in the first and second ultrasound are compared and correlated with clinical signs. We do laparoscopic appendectomy. We do not do diagnostic laparoscopy as an investigative tool. In some of the acute abdomen that macroscopically showed normal appendix, HPE did reveal helminth or inflammatory changes. In cases where there was definite leucocytosis and acute abdomen with macroscopically normal appendix, our pathologist would be informed and we have had cases of leukaemic infiltrates and other rare causes of appendicitis. I hope this explanation helps :)

as a protocol in our hospital we do appendectomy in a male patient with RLQ pain and positive physical examination in serial exam but in female patient we are more sensitive and decision for operation we need more evidence to confirm diagnosis.

in equivocal cases especially female, obese patient we do diagnostic laparoscopy.

Hi and thanks Ms Dayang Anita Abdul Aziz! Now I do understand your way more clearly. Very interesting is the issue that you tell us that obese children do not show the sign of anorexia...

I will check in our patients now, too. Maybe obesity shows a different pattern of signs in appendicitis?

60 to 70% of the times is clínical diagnosis.  The other 30 to 40% requieres abdominal ultrasound. hae of thes

PATHOFGENESIS ! Anatomy- The appendix is invested like a small intestine but is blind. Etiology: Stage I: ProdromaBlockage in the lumen, by e.g. any foreign body or an enlarging, infected lymThis prodroma takes about 5 hours. ph node (Payers patch -->absceProdromass), the appendix  will try to expel it. If succesful symptoms disappear If not--> Inflammation supervenes( Tumor, Dolor, Calor Rubor). Nerve supply from coeliac axis-->mesenteric symptoms like anorexia, nausea, epigastric distress, etc. may  be present.  This prodroma takes about 5 hours. Stage II: If onstruction is unrelieved --> colicky pains start.

Sorry, I accidentally hit the wrong key...so...to continue: -->Stage II: Pain: Also on or about 5 hours. With continuing obstruction- the colicky abdominal pain starts in the right lower quadrant (RLQ). Abdomen still soft.  WBC ount still normal. CT may show FB but. Ultrasound useless. Stage III: Peritoneal Irritation: Inflammation proceeds through the wall to the serosa and irritates the peritoneum.  RLQ is guarding, harder, tender, with beginning rebound.  WBC rising. Stage IV:Spreading RLQ Peritonitis: All local symptoms now  are unequivocal, WBC up ( except: late in elderly  and those with relative adrenal insufficiency.) Stage V: Preperforation: All classical  local and general symtoms present. Stahe VI- Post perforation & Spreading peritonitis -  you do not need labs.  All the stages take on or about four to five hours each, so always ask when the prodromal S&S  started and factor in the chronology . Ultrasound is useless because by the time it is positive you already have a diagnosis. CT scan may see the fecalith sooner but collections only starts after peritoneal irritation stage. Gastrografin enema will also show the blockage. Rebound dtarts sooner than the CT scan will see . Antibiotics will work only in infection, not in obstruction. Before  preperforation, the appendicitis can still resolve if the appendix expels the obstruction or abscess drains intraluminally. Advice: Take your chronologically timed history and perform your PE and be the master of technology not enslaved by it.

I think It ought to be 15-20(max) % of the ones taken to the operating room for appendectomy.

For teaching hospital- 25% as students are involved. At consultant level 10-15%.

It the rates are low you are likely missing out.

For teaching hospital- 25% as students are involved. At consultant level 10-15%.

It the rates are low you are likely missing out.

I think  10 max % in childern, so they are very good to diagnstic by ultrasound

Provided you can adopt blood tests, including WBC, C-reactive Protein and Procalcitonin, experienced pediatric surgeons and good radiologist for abdominal USS, I think that 3% is the highest acceptable negative appendectomy rate for those patients who undergo surgery in emergency.

Conversely, in case of Recurrent Abdominal Pain (RAP), the rate of normal appendices approaches 100% (interval appendectomies excluded) being 20-30% of times enterobius vermcularis detected within the appendiceal lumen. Nonetheless, the effectiveness of laparoscopic surgery and appendectomy in case of RAP approaches 90% thus suggesting a sort of chronic irritability of the appendix itself, regardless of the presence of any histological abnormalities. This prompts us to perform Laparoscopic exploration and appendectomy in any kid (mostly girls) with recurrent abdominal pain lasting longer than 3 months with significant interference with daily activities (school loss, sports interruption, night-time awakening).

Unfortunately in my experience, the time of having an emergent mid night appendectomy still exist, and often are those appendicitis previously judged uncomplicated  or absent.