Most common non obstetrical surgical complication of pregnancy: appendicitis

Among the surgical complications of pregnancy appendicitis  is the most common non obstetric complication.
The appendix is a vestigial organ which will be present in the form of  long diverticulum that extends from the inferior tip of the cecum. Its lining contains intermittent  lymphoid follicles.

Appendicitis, inflammatory condition of the appendix,   is the  most common surgical condition of the abdomen in general population.

Lifetime occurrence of the appendicitis in general population  is 7%.

Peak incidence  of the appendicitis is between  10-30y of age.

Pathogenesis of the appendicitis:

Appendicitis commonly occurs due to the appendiceal lumen obstruction.  Which may be due to various reasons like  lymphoid hyperplasia(due to viral illnesses or upper respiratory infection or mononucleosis or gastroenteritis etc.), fecoliths , parasites, foreign bodies etc  obstructing the appendiceal lumen and leading to inflammation of appendix, the appendicitis.

Other systemic diseases like crohn’s disease, primary  or  metastatic cancer involving the bowel, carcinoid syndrome etc can also lead to appendicitis by obstructing the lumen of appendix.

Incidence during pregnancy:

The Incidence of appendicitis during pregnancy is  0.05%.

One among 1000 pregnant women  will undergo appendectomy.  
Among them 1 in 1500 pregnant women will be  proved  cases of appendicitis.

 The incidence of appendicitis during  1^st trimester , 2^nd trimester, and 3^rd trimester are 30%, 45% and 25%  respectively.   
Whereas  the chances of rupture during  1^st trimester , 2^nd trimester, and 3^rd trimester are 22%, 27% and 50% respectively.

 Appendicitis  is slightly more common in the second trimester than in the first and third trimesters or postpartum.

 Rupture of  infected appendix is more likely  during pregnancy, especially in the third trimester, may be  because of change in anatomical position or delay in diagnosis and intervention.

Comparitively appendicitis is having lower incidence in females suggesting some relation with female sex hormones.  
As in pregnancy there will increase in the levels of female sex hormones, lower incidence may be substantiated.  So, pregnancy having a protective effect from appendicitis  especially the third trimester.

Symptoms of appendicitis:

Pain is the main symptom of appendicitis. 
Pain can occur in the RLQ(right lower quadrant) commonly  as, the appendix has an intraperitoneal location either anterior or retrocecal, and may come in contact with the anterior parietal peritoneum when it is inflamed.

Normally in pregnancy, the location of the appendix  changes significantly because of the growth of the uterus mainiy from  fourth to fifth months of gestation. 
Sometimes the appendix may be in pelvic, retroileal or retrocolic position. These changes in position leads to  changes the clinical manifestations of appendicitis.
 Depending on the  position of appendix pain can also come in the RUQ(right upper quadrant) or  in the flanks.

Vomiting  and  nausea are the other symptoms of appendicitis.

Pain migration can occur, it may start at the umbilicus and later migrate to right lower quadrant etc.

Fever presents as one of the initial  symptoms in some cases.

Signs of appendicitis:

Tenderness  can be noted in right lower quadrant  which is the single most important sign.

Rebound  tenderness & guarding of abdominal wall may present which are the peritoneal signs.

Other confirmatory peritoneal signs of appendicitis are as follows but absence of these signs does not exclude appendicitis:

Rovsing sign:  to demonstrate this sign,  when we palpate the left lower quadrant pain will be felt in right lower quadrant.

Dunphy’s sign: in this we have to ask the patient to cough which will increase the  pain.

Psoas sign: can be demonstrated in case of  retroperitoneal  retrocecal appendix , in it  pain felt on extension of right thigh.

Obturator sign: is seen in case of pelvic appendix, in which  pain will be noticed on extension of right thigh.

Rectal examination tenderness  may be noted when appendix is at cul-de-sac.

 Flank tenderness in right lower quadrant may be noted when the appendix is in retroperitoneal retrocecal position.
  The posture of the patient will also be typical, patient maintains hip flexion with knees drawn up to obtain relief from pain.

 Low grade fever of around 38°C is one of the common sign of appendicitis  will be normally but absence of fever or high grade fever can also occur.

Investigations:

Laboratory tests:

Sometimes the history given by patient and physical examination will not confirm the diagnosis and also some of the symptoms of pregnancy mimic appendicitis and lead to confusion in diagnosis at that time laboratory and radiological tests will  help.

WBC(white blood cell count):  
Normal white cell count will be between 4000 to 10,000/mm3, it will be elevated in  80% cases of appendicitis, neutrophilia is common. 
But in pregnancy also there will be elevation in WBC count, so this is less useful. 
But serial measurements may increase the specificity.

CRP (C-reactive protein): 
Estimation of  C-reactive protein level is an useful test. It will be elevated in  appendicitis to greater than 0.8 mg per dl. 
Combination of elevated C-reactive protein level, an elevated WBC count and neutrophilia are much useful in diagnosis than any single factor.

Urinalysis:
 In appendicitis, the patient’s  urinalysis may show mild pyuria, proteinuria and hematuria. 
This test is more useful to differentiate between urinary tract infection causing abdominal pain from appendicitis related abdominal pain.

Radiological tests:

  Plain x ray:  is not much helpful can be used to rule out other causes of abdominal pain. 
 In pregnancy normally radiographs are avoided to prevent radiation exposure to the fetus.

Barium enema, which was used previously is not used now a day as many better methods have came. And also  this is not preferable in pregnancy.

Ultrasonography:

 Is useful in pregnants as there is no exposure to radiation. 
To rule out appendicitis, a normal appendix with 6 mm or less in diameter to be  identified in ultrasonography.

 In case of appendicitis the inflamed appendix will be more than  6 mm in diameter,  it will be  noncompressible and tenderness will felt on focal compression.

But false positive findings can come in some other causes causing  right lower quadrant pain. 
Eg. inflammatory bowel disease, cecal diverticulitis, Meckel's diverticulum, endometriosis and pelvic inflammatory disease etc.

Computed tomographic (CT) scans:

In CT scans, generally appendiceal CT is preferable in which oral contrast may be given after a gastrografin-saline enema in which intravenous contrast is not needed.  

CT can identify the normal appendix better compared with  the ultrasonography. But CT is not recommended generally in pregnancy because of increased chances of radiation exposure.

MRI:
MRI is preferable alternative to CT. As there is no risk of radiation exposure. 

Differential diagnosis:

Surgical conditions mimicking the  appendicitis are :  renal stone,  gastroenteritis, pancreatitis, cholecystitis, mesenteric adenitis, hernia, bowel obstruction,  pyelonephritis  etc.

Gynecological conditions mimicking the appendicitis are:  preterm labor, placenta abruptio, chorioamnionitis,  adnexal torsion, ectopic pregnancy, pelvic inflammatory disease, round ligament  pain,  uterine myoma degeneration etc.

Treatment:

If appendicitis is suspected during pregnancy  better to go for  immediate surgical intervention.

Delay  in treatment can cause perforation of appendix, generalized peritonitis etc.

Antimicrobial therapy has to be started  prior to surgery.  2^nd generation cephalosporins can be used peri operatively.

Tocolytics can be used to calm the uterus from insult of acute abdomen. But their usage is controversial. 

Ritodrine is not that much effective, it can also cause tachycardia & vomiting.

anti-prostaglandin   drugs are having side effects like  anti-inflammatory,  antipyretic and fetal side effects.

Surgery:

 In pregnant patients also as in nonpregnant patients, appendectomy is the standard for treatment. 
Surgey can be done by either laparotomy or by laparoscopy methods.

But in around 20% cases  negative appendectomies are done. Because of this  nonoperative management with parenteral antibiotic treatment is done in some cases, but 40 percent of these patients eventually required appendectomy. 
So,  better to go for surgical treatment when strong suspicion is there instead of wasting time and facing consequences.

Complications of surgical procedure will show effect on  pregnancy outcome.  Perinatal morbidity  in nonobstetrical surgery in pregnancy is attributable to the disease itself.

In uncomplicated cases the maternal mortality is less and the overall fetal mortality rate is 2 to 8.5 percent. 
But it may increase to as high as 35 percent in case of perforation with generalized peritonitis.

Laparotomy:

Appendectomy by laparotomy  is the procedure which is most commonly employed in the treatment of appendicitis.

In it the incision of choice in all trimesters  is at the  McBurney’s point only. It is the point which is present on the spino umbilical line,  at 1/3 of distance from iliac spine. 

And the procedure is same as in non-pregnant patients.

Laparoscopy:

 Laparoscopy is  advised in some cases as it is having the advantage of less post-operative complications.

But laparoscopy is having the disadvantage that Co2 pneumo peritoneum has to be created during the procedure which will cause decreased uterine blood flow leading to fetal acidosis and premature labor.

Laparoscopy is safe especially in 1^st half of pregnancy (as size of gravid uterus will be less).  And similar perinatal outcomes with laparoscopy compared to laparotomies are noted.

The mortality of appendicitis complicating pregnancy is to be taken as the mortality of delay.

Complications during pregnancy due to appendicitis and its treatment:

 As the gestational age  increases the  complication rate also increases.

 Uterine contractions  may start in  80% of cases over 24 weeks of gestation.

 In conditions when appendicitis occurs in  3^rd trimester and in case of perforated appendix & peritonitis preterm labor can develop.

 When appendicitis occurs in 1^st trimester, abortion can occur.  Fetal loss  is around 15%.

 After appendicitis and its treatment fetus may develop with decreased birth weight .

 Other surgical complication like wound infection, atelectasis etc may develop.

But there will be  no increased infertility, no congenital malformation and no stillborn infants after  proper treatment.

Perforated appendicitis:

Incidence of perforated appendicitis is  4 -19% in  non-pregnant patients and increases to  57%   in pregnant women.

As the gestational age  increase the chances of  perforations  and peritonitis also increase.

Perforation is more common in pregnancy may be because of the change of  position of appendix  leading to  no containment of infection by omentum  and  inability of the omentum to isolate infection leads to more generalized peritonitis.

And no direct cause and effect relationship  noted between duration of symptoms and perforation or between time to operative intervention and perforation.

 When generalized peritonitis results from perforation the  physical findings become more obvious leading to complete abdominal tenderness.

 When appendicular abscess forms it will present as an ill-defined mass felt in the right lower quadrant.

 Compared with imperforated appendix, fever is more common with rupture. And the WBC count may be elevate to 20,000 to 30,000 per mm³.

 A periappendiceal abscess can be treated in two ways either by immediate surgery or by nonoperative management.

 During  nonoperative management parenteral antibiotics are to be given and patient to be kept in  observation or in case of accumulation of inflammatory fluid CT-guided drainage can be done, followed by appendectomy six weeks to three months later, which is called interval appendectomy.

Appendicitis during puerperium:

Incidence of appendicitis and chances of perforation are high during puerperium.

Appendicitis can stimulate labor,  after the uterus empties there may develop diffuse peritonitis in puerperium if perforation occurs.

Surgical treatment can be given under antibiotic coverage.

Usually prognosis is  generally good in puerperal period.